INTEGUMENTARY B.

STRATUM SPINOSUM (SPINY

SYSTEM LAYER)
 is immediately superficial to the
- The integumentary system is an basal layer
organ system consisting of the skin,  its cells appear spiky (hence their
hair, nails, and exocrine glands. Its name) because as skin is
primary function is to act as a prepared for histological
barrier to protect the body from examination, its cells – shrink but
outside world. Additionally, it helps their desmosomes hold tight
regulate temperature and is involved  cells in the basal and spiny layers
in sensory perception. The skin, the are the only ones that receive
largest organ of the system, is made adequate nourishment
up of multiple layers, each with its
own unique properties and functions. C. STRATUM GRANUSOLUM
THE SKIN (GRANULAR LAYER)
 is named for the abundant
- The major organ of the granules in its cells
integumentary system. The skin  some of these granules contain a
does much more than just cover the waterproofing glycolipid that is
body exterior. secreted into the extracellular
space
PARTS OF THE SKIN
D. STRATUM LUCIDUM (CLEAR
1. EPIDERMIS LAYER)
- The outer layer that you can see or  is a thin translucent band of
feel. It protects the body from flattened dea keratinocytes
damage and helps regulate body  is present only on thick skin, such
temperature. as the palms of the hands and
soles of feet
LAYERS OF EPIDERMIS
A. STRATUM BASALE (BASAL E. STRATUM CORNEUM (HORNY
LAYER) LAYER)
 a single row of cells that abuts  the outermost epidermal layer, is
the dermis 20 to 30 cell layers thick and
 its cells constantly undergo cell comprises most of the epidermal
division to produce millions of thickness
new cells daily  the cells in this layer are dead,
 about a quarter of the cells in this and their flattened remnants,
stratum are the spidery, brown- filled with keratin, resemble
to-black pigment producing cells scales
called melanocytes 2. DERMIS
 - The layer under the epidermis. It that is an excellent source of
contains nerve endings, the blood nutrients for the bacteria typically
vessels, oil glands, and sweat glands found on the skin

3. PAPILLARY LAYER 4. SEBACEOUS (OIL) GLAND

- The more superficial papillary layer - Found nearly all over the skin,
is very uneven and has fingerlike except for the palms of the hands
projections from its superior surface, and the soles of the feet. Their ducts
called dermal papillae, which attach usually empty into a hair follicle, but
it to the epidermis above some open directly onto the skin
surface
4. RETICULAR LAYER - Ex: sebum, acne, blackhead
- The deepest skin layers. It contains
blood vessels, sweat and sebaceous 5. HAIR
glands, and pressure receptors - Are found over the entire body
(Pacinian receptors) surface, except for the palms of the
hands, the soles of the feet, parts of
5. HYPODERMIS the external genitalia, the nipples
- The deepest layer of the skin. It and the lips
connects the dermis layer to the
muscles and bones. It contains a 6. HAIR BULB
layer of adipose tissue - Forms the base of the hair follicle. In
the hair bulb, cells divide to build
and grow the hair
APPENDAGES OF THE SKIN
7. NAILS
1. SWEAT GLAND
- Hornlike derivatives of the
- It makes sweat. Its main function is
epidermis, are transparent and
to control body temperature. Sweat
nearly colorless, but they appear
is mainly water, but it also contains
pink because of the blood supply in
some salts
the underlying dermis

2. ECCRINE GLAND
- Distributed all over the body, FUNCTION OF THE SKIN
produce clear perspiration,
1. WOUND HEALING
consisting primarily of water, salts
- Involves four phases:
(mostly NaCl), and urea
 Hemostasis
 Inflammation
3. APOCRINE GLAND
 Proliferation
- Found chiefly in the axillary and
 Remodeling
genital areas, secrete a milky protein
- Hemostasis triggers fibrin clot
and fat-rich substance (also
formation
containing water, salts, and urea)
 - Inflammation eliminates pathogens - Eczema is a chronic skin condition
proliferation forms granulation affecting both children and adults,
tissue, and influenced by epidermal junction
- Remodeling restores tissue defects, reduced skin immunity, and
architecture through apoptosis and genetics. Itching, a hallmark
matrix metalloproteases. This symptom, is often triggered by
process involves immune cells, environmental factors, leading to
fibroblasts, and myofibroblasts, skin lichenification
forming a collagen network
3. PSORIASIS
2. REGULATION OF BODY - Chronic plaque psoriasis, the most
TEMPERATURE common subtype, presents as well-
- The skin’s extensive vascular defined red plaques covered with
network and large surface area silvery scales. Approximately half of
facilitate efficient heat conservation patients experience itching. These
and release through vasoconstriction lesions primarily occur on extensor
and vasodilation. Blood vessels surfaces and exhibit a symmetric
dilate, sweat evaporation aids, and distribution. The condition’s
hair traps heat pathophysiology involves excessive
keratinocyte proliferation in the
3. PHYSICAL PROTECTION epidermis and immune system
- The integumentary system, dysregulation
composed of layers of cells, provides
physical protection to the body, 4. ALOPECIA AREATA
including the epidermis, dermis, - a disease that happens when the
hypodermis, glands, nails, and hairs, immune system attacks hair follicles
ensuring blood supply, sensory and causes hair loss. Hair follicles
perception, and protection and causes hair loss. Hair follicles
are the structures in skin that form
hair. While hair can be lost from any
SKIN CONDITIONS
part of the body, alopecia areata
1. ACNE usually affects the head and face.
- Is a common skin condition causing
inflammation of hair follicles due to 5. BURN
excess keratin, sebum, and - burn result from excessive heat,
cutibacterium acnes bacteria. Factors radiation, or chemical exposure, and
include skin trauma, diet, stress, and grading the severity of the burn is by
hormonal fluctuations the depth and area of skin
involvement

2. ATOPIC DERMATITIS
6. NAIL PITTING
 - Is when small round depressions or
notches appear in the nails. It’s
common in people who have skin SKELETAL SYSTEM
disorders such as psoriasis and
FUNCTIONS
eczema
- Our body’s support structure
7. AGING CHANGES SKIN - Gives our body its shape
- Skin changes are among the most - Allows movement
visible signs of aging. Evidence of - Makes blood cells
increasing age includes wrinkles and - Provides protection for our organs
sagging skin. Whitening or graying and stores minerals
of the hair is another obvious sign of
ORGANS
aging
- As we age, the skin’s outer layer, the 1. Bones
epidermis, becomes thinner, with 2. Cartilages
melanocytes decreasing and 3. Ligaments
remaining cells increasing. This 4. Joints
results in thinner, paler, and clearer
skin, with lentigos in sun-exposed
ANATOMY OF THE SKELETAL SYSTEM
areas and elastosis in sun-exposed
areas 1. Bones
2. Bone tissues
SKIN DISORDERS CAN BE CAUSED BY
3. Bone cells
MANY CONDITIONS

- Blood vessel diseases, such as

atherosclerosis BONES
- Diabetes
- Primarily give support to the
- Heart disease
appendages and protect the fragile
- Liver disease
organs of the body such as the
- Nutritional deficiencies
brain, spinal cord, heart, and lungs
- Obesity
- Also store calcium and phosphorus in
- Reactions to medicines
the hard bone matrix, which can be
- Stress
released when needed elsewhere
- The bumps, ridges, and grooves on
the surface of bones provide
OTHER CAUSES OF SKIN CHANGES
attachment sites for the skeletal
- Allergies to plants and other muscles
substances - Additionally, many bones contain a
- Climate soft tissue called marrow that
- Clothing produces new blood cells and stores
- Exposure to industrial and household fat
chemicals indoor heating
 - Is one of the hardest parts of the IN EMBRYOS
body, very lightweight, and can
- Skeleton made of hyaline cartilage
release tension
- Gets replaced by bone with age
A. Calcium salts make it hard
B. Collagen fibers make it strong
and flexible
CARTILAGE remains in a few places
- The adult human skeleton is a
framework of 206 bones and is - Bridge of nose
anatomically divided into two parts: - Parts of ribs
A. Axial skeleton - Joints
B. Appendicular skeleton
BONE GROWTH

FUNCTIONS OF BONES - Epiphyseal plates allow for growth of

long bone during children
1. SUPPORT
- New cartilage is continuously formed
- Internal framework of the body
- Older cartilage becomes ossified
- Ex: legs support body trunk, rib cage
A. Cartilage is broken down
supports chest wall
B. Bone replaces cartilage
- Bones remodeled, lengthened until
2. PROTECTION
growth stops
- Protects soft body organs
A. Bones change shape somewhat
- Ex: skull protects brain, ribs protect
B. Bones grow in width
heart and lungs etc.

3. BLOOD CELL FORMATION

TYPES OF BONE CELLS
- Hematopoiesis—occurs in bone
marrow of long bones - Osteocyte—mature bone cell
- Osteoblast—bone builders
4. STORAGE - Osteoclast—"bone destroyers,”
- Fat storage—in yellow marrow break down bone matrix to remodel
- Mineral storage—phosphorus and and/or release calcium
others

5. MOVEMENT BONE REMODELLING

- Muscles use bones as levers to move - Bone remodeling is done by
body osteoblasts and osteoclasts
- Not a function skeletal system can - Essential for bones to keep normal
do on its own proportions and strength
- Bones get larger/thicker when;
 Large muscles are attached to
BONE FORMATION them
  Need more bone to attach the - Made of compact bone surrounding
large muscle to spongy bone
 Bones get smaller/weaker; - Covered with articular cartilage—
a. Physical inactivity smooth, glassy, decreases friction at
b. Non-use of muscles—atrophy joints
c. Small muscles don’t need large
bones to attach to 3. EPIPHYSEAL LINE
d. Bones remodeled to become - Line of bone tissue that looks
smaller different from rest of bone
- Remnant of epiphyseal plate
- Hyaline cartilage
BONE CLASSIFICATION - Causes long bones to grow
lengthwise
1. LONG BONES
- Longer than wide
4. PERIOSTEUM
- Contain shaft with head at each end
- Outer covering of shaft
- Mostly compact bone
- Like “skin” on chicken bone
- Ex: Limbs (not ankle or wrist bone)

5. SHARPEY’S FIBERS
2. SHORT BONES
- Attach periosteum to bone
- Cube-shaped
- Mostly spongy bone
6. ARTERIES
- Ex: Wrist and ankle bones, patella
- Supply nutrients to bone cells
(kneecap)

7. MEDULLARY CAVITY
3. FLAT BONES
- In shaft
- Thin, flat, usually curved
- Contains yellow marrow (adipose) in
- Two layers of compact bone with
adults
spongy bone in between
- Contains red marrow in infants (for
- Ex: Skull, ribs, breastbone
blood cell formation)
4. IRREGULAR BONES
- Don’t fit into the other categories MICROSCOPIC ANATOMY OF BONES
- Ex: Vertebrae, hip bones
1. OSTEON (HAVERSIAN CANAL)
- Unit of bone
LONG BONE ANATOMY
2. CENTRAL (HAVERSIAN) CANAL
1. DIAPHYSIS - Opening in center of osteon
- Shaft - Contains blood vessels
- Made of compact bone
2. EPIPHYSES 3. PERFORATING (VOLKMAN’S)
- Ends of long bone CANAL
 - Perpendicular to central canal B. Lower limbs (legs)
- Contains blood vessels and nerves C. Pelvic girdle
D. Pectoral girdle
4. LACUNAE
- Cavities that contain osteocytes
(bone cells) AXIAL SKELETON
- Arranged in concentric rings (like
- The core of the skeleton is referred
tree rings)
to as the axial skeleton. It contains
the following 80 bones
5. LAMELLAE
- The upright posture of humans is
- Rings around the central canal
maintained by the axial skeleton,
- Where the lacunae can be found
which transmits the weight from the
head, the trunk, and the upper
6. CANALICULI
extremities down to the lower
- Tiny canals
extremities at the hip joints
- Radiate from central canal to lacunae
- Skull: 22 bones
- Transport nutrients to bone cells
- Hyoid: 1 bone
- Vertebrae: 32-34 bones
- Ribs: 24 bones
BONE TISSUES
- Sternum: 1 bone
1. COMPACT BONE
- Homogenous appearance
- Dense, looks smooth SKULL

- Consists of 22 bones and 7

2. SPONGY BONE
associated bones.
- Small, needle-like pieces
- They fall into two main groups:
- Lots of open spaces
A. One group (including the frontal,
- Looks like a sponge; hence the name
parietal, and temporal bones)
surrounds the brain and is fused
together to form the cranium
COMPONENTS OF THE SKELETAL
B. The remainder of the bones form
SYSTEM
the face
THE HUMAN SKELETON CAN BE - Sutures
DIVIDED INTO TWO  interlocking, immovable joints
holding most skull bones together
1. AXIAL SKELETON
- Mandible-only freely movable bone
A. Skull
in skull
B. Vertebral column
C. Rib cage

2. APPENDICULAR SKELETON
FETAL SKULL
A. Upper limbs (arms)
 - Large in comparison to body length - Hollow portions of bone around nasal
of infant cavity
- Contains fontanelles—soft fibrous - Named for bones they are found in
membranes connecting cranial bones - Lighten skull
- “Soft spots” - Amplify sounds when speaking/ give
- Usually convert to bone around resonance
24 months after birth

BONY THORAX
VERTEBRAL COLUMN
- Forms a cage to protect organs
- This highly flexible structure, also
- 3 parts:
called the vertebral column, supports
A. Sternum
the head and body
B. Rib cage
- It also protects the delicate tissues
C. Thoracic vertebrae
of the spinal cord
- It is made up of 32-34 bones
1. Sternum
called vertebrae, separated by
- Flat bone
intervertebral discs, which act as
- 3 fused bones:
shock absorbers
A. Manubrium
- The bones of the spine are kept in
B. Body
place and supported by attached
C. Xyphoid process
ligaments and muscles
- Attached to first 7 pair of ribs

VERTEBRAE NAMED FOR THEIR 2. Rib cage

LOCATION - 12 pairs
A. True ribs—7 pair
 7 cervical vertebrae:
B. False ribs—5 pair
- C1 = atlas
C. Floating ribs—2 pair
- C2 = axis
 12 thoracic vertebrae
3. Thoracic vertebrae
 5 lumbar vertebrae
 Sacrum
- 5 fused vertebrae
APPENDICULAR SKELETON
 Coccyx
- 4 fused vertebrae - Their function is to make locomotion
 Vertebrae separated by possible and to protect the major
fibrocartilage discs organs and digestion, excretion, and
- Cushions/absorbs shock reproduction

PARANASAL SINUSES DIVIDED INTO SIX MAJOR ORGANS:

 1. Pectoral girdle (4 bones) - Structure/function
A. Left and right clavicle—2
B. Left and right scapula—2 1. Fibrous joints
- Immovable
2. Arms and forearms (6 bones) - Ex: sutures of skull
A. Left and right humerus—2
B. Ulna—2 2. Cartilaginous joints
C. Radius—2 - Immovable or slightly movable
- Ex: pubic symphysis and vertebrae
3. Hands (54 bones)
A. Left and right carpals—16 3. Synovial joints
B. Metacarpals—10 - Freely movable
C. Proximal phalanges—10 - Ex: knees, elbows, and shoulder
D. Intermediate phalanges—8
E. Distal phalanges—10
SYNOVIAL JOINTS
4. Pelvis (2 bones)
- Articulating bones separated by joint
A. Left and right hip bone—2 cavity
A. Articular cartilage covers bone
ends
5. Thighs and legs (8 bones)
B. Joint surfaces enclosed by fibrous
A. Left and right femur—2
capsule
B. Patella—2
C. Cavity contains synovial fluid
C. Tibia—2
D. Ligaments help reinforce the joint
D. Fibula—2
- Associated joint structures:
1. Bursae
6. Feet and ankles (52 bones)
 flat fibrous sacs
A. Left and right tarsals—14
 lined with synovial membrane
B. Metatarsals—10
 contains synovial fluid
C. Proximal phalanges—10
 common where ligaments,
D. Intermediate phalanges—8
muscles, skin, tendons rub
E. Distal phalanges—10
together

JOINTS 2. Tendon sheath

 elongated bursa wrapping around
- Articulations of bones
a tendon that deals with lots of
friction
FUNCTIONS OF JOINTS  like a bun around hotdog
- Hold bones together
- Mobility
TYPES OF SYNOVIAL JOINTS BY
JOINTS ARE CLASSIFIED AS SHAPE
 A. Plane joint—carpals - Broken bone portion is pressed
B. Hinge joint—ulna, humerus inward
C. Pivot joint—ulna, radius - Typical of skull fracture
D. Condyloid joint—metacarpal,
phalanx 4. IMPACTED
E. Saddle joint—metacarpal, carpal - Broken bone ends are forced into
F. Ball-and-socket joint—head of each other
humerus, scapula - Commonly occurs when one
attempts to break a fall with
outstretched arms
FRACTURES
5. SPIRAL
- A break in bone
- Ragged break occurs when excessive
twisting forces are applied to a bone
- Common sports fracture
TYPES OF FRACTURES

1. SIMPLE (CLOSED) FRACTURE 6. GREENSTICK

- Bone breaks cleanly, does not - Bone breaks incompletely, much in
penetrate skin the way a green adult
- Common in children, whose bones
2. COMPOUND (OPEN) FRACTURE are more flexible than those of
- When bone ends penetrate through adults
skin
- Treated by reduction and
BONE REPAIR
immobilization
HEMATOMA FORMS
3. REALIGNMENT OF BONE ENDS
- Blood vessels rupture when bone
breaks
- Blood filled swelling
COMMON FRACTURES
- Cells without nutrients die
1. COMMINUTED
- Bone breaks into many fragments
FIBROCARTILAGE CALLUS FORMS
- Particularly common in the aged,
whose bones are more brittle - Made of connective tissue
- Splints the break
2. COMPRESSION - Phagocytes dispose of dead tissue
- Bone is crushed (e.g., osteoporotic
bones)
BONY CALLUS FORMS
- Common in porous bones
- Osteoblasts/clasts move in, create
3. DEPRESSED callus of spongy bone
REMODELING - Malignant tumors originating in bone
tissue, leading to pain, fractures,
- Osteoblasts/clasts remodel in
and systemic symptoms
response to stress on the bone
- Helps strengthen bone
- Creates a permanent “patch” at the
WAYS TO MAINTAIN BONE HEALTH
site
- Often, a healed fracture can be - Eat healthy food
stronger than the rest of the bone - Engage in weight-bearing exercises
- Avoid smoking
- Limit caffeine and alcohol
SKELETAL DISORDERS AND consumption
CONDITIONS - Get regular sunlight exposure
- Take supplements (if recommended
1. OSTEOPOROSIS
by your doctor)
- Is a condition characterized by
- Practice good posture
weakened bones and increased risk
- Maintain a stable weight
of fractures due to bone loss and
- Get a bone density test
decreased bone density

2. ARTHRITIS
- Is an inflammation of joints leading MUSCULAR SYSTEM
to pain, stiffness, and reduced
- The muscular system is made up of
mobility, with various types such as
specialized cells called muscle fibers.
osteoarthritis and rheumatoid
Their primary function is
arthritis
contractibility
- Movement is controlled by muscles,
3. FRACTURES
which are attached to bones, internal
- Breaks or cracks in bone tissue
organs, and blood vessels
resulting from trauma, overuse, or
- Internal movement involves the
underlying
contraction and relaxation of visceral
muscles, whereas external
4. SCOLIOSIS
movement involves the contraction
- Is an abnormal lateral curvature of
and relaxation of bone-attached
the spine, often diagnosed during
muscles
adolescence and may require bracing
- Muscles are classified into three
or surgical intervention
types:
 Skeletal
 Cardiac
 Smooth
5. BONE CANCER

FUNCTIONS
 1. PRODUCING MOVEMENT - Chewing and swallowing, which are
- Skeletal muscles are responsible for the first parts of digestion
the overall mobility of the body, - Expanding and contracting your
enabling quick response to external chest cavity so you can inhale and
changes. exhale at will
- Maintaining body posture
2. MAINTAINING POSTURE - Moving the bones in different parts
- Skeletal muscles, often unnoticed, of the body
continuously adjust posture to - Protecting joints and holding them in
maintain erect of seated positions place
despite gravity’s constant downward
pull
STRUCTURE OF SKELETAL MUSCLE
3. STABILIZING JOINTS
A. EPIMYSIUM
- Skeletal muscles and muscle
- The outermost layer of tissue
tendons play a crucial role in
surrounding the entire muscle
reinforcing and stabilizing joints with
poorly fitting articulating surfaces,
B. PERIMYSIUM
enabling movement and preventing
- The middle layer surrounding
deterioration of the skeleton
bundles of muscle fibers

4. GENERATING HEAT
C. ENDOMYSIUM
- Muscle activity generates body heat,
- The innermost layer surrounding
which is crucial for maintaining
individual muscle fibers
normal body temperature, as ATP is
used to power muscle contraction,
releasing nearly three-quarters its
2. CARDIAC MUSCLE
energy
- Is an involuntary muscle, forms the
heart’s walls and pumps blood
through the body, influenced by
TYPES OF MUSCLE TISSUES
hormones and nervous system
1. SKELETAL MUSCLE stimuli, and electrical impulses
- Skeletal muscles, comprising 40% of - Also called myocardium
a person’s weight, create movement - Circulatory System
through nerve signals
- Skeletal muscle is found throughout FUNCTION OF CARDIAC MUSCLE
the body, attached to bones via - Cardiac muscle tissue works to keep
tendons. Skeletal muscle is also your heart pumping through
present in the tongue, diaphragm, involuntary movements
eye socket, and upper esophagus - It does this through specialized cells
called pacemaker cells. These
FUNCTIONS OF SKELETAL MUSCLE
control the contractions of your heart
- Pacemaker cells—is a myocardial - Actin and Myosin act as the main
cell with an intrinsic ability to proteins involved in muscle
depolarize rhythmically and initiate contraction
an action potential - Smooth muscle can tense and relax
- These contractile functions of the but has greater elastic properties
heart require ATP, which can be than striated muscle. This quality is
obtained through various substrates, important in organ systems like the
including fatty acids, carbohydrates, urinary bladder, where the
proteins, and ketones preservation of contractile tone is
necessity
LAYERS OF CARDIAC MUSCLE
A. ENDOCARDIUM ORGAN SYSTEM INVOLVED
- Innermost layer of the heart, lines A. GASTROINTESTINAL TRACT—
the chambers and extends over propulsion of the food bolus
projecting structures
B. CARDIOVASCULAR—regulation
B. MYOCARDIUM of blood flow and pressure via
- Make up the middle and thickest vascular resistance
layer of the heart wall
C. RENAL—regulation of urine flow
C. EPICARDIUM
- Inner layer of the pericardium D. GENITAL—contractions during
- Makes up part of the pericardium pregnancy, propulsion of sperm
that surrounds and protects the
heart E. RESPIRATORY TRACT—
regulation of bronchiole diameter
3. SMOOTH MUSCLE
- Like cardiac muscle, forms hollow F. INTEGUMENT—raises hair with
organ walls, respiratory erector pili muscle
passageways, and blood vessels,
propelling things through the body G. SENSORY—dilation and
and contracting in response to constriction of the pupil as well as
stimuli and nerve impulses changing less shape

FUNCTIONS OF SMOOTH MUSCLE

- Smooth muscle functions as an
involuntary non-striated muscle
- Contains thick and thin filaments
TYPES OF BODY MOVEMENTS
that do not arrange into sarcomeres,
resulting in a non-striated pattern 1. ORIGIN AND INSERTION
- Contains large amounts of actin and - the origin is attached to an
myosin immovable bone, while the insertion
 is attached to a movable bone. When of the jaw, arm at shoulders, and
the muscle contracts, the insertion mandible, respectively.
moves towards the origin
8. DORSIFLEXION AND
2. FLEXION AND INSERTION PLANTARFLEXION
- Are key joints mechanics, with - Dorsiflexion involves lifting the
flexion decreasing joint angle and foot to approach the shin, while
extension increasing the angle plantar flexion involves depressing
between bones or body parts the foot.

3. ROTATION 9. INVERSION AND EVERSION

- Is the movement of a bone around a - To invert the foot, turn the sole
longitudinal axis, a common feature medially, and to evert the foot, turn
of ball and socket joints. the sole laterally.

4. ABDUCTION AND ADDUCTION 10. SUPINATION AND

- involves a limb moving away from PRONATION
the body's midline, while adduction - Supination occurs when the forearm
involves a limb moving towards the rotates laterally, while pronation
midline. occurs when it rotates medially.
Opposition, facilitated by the saddle
5. CIRCUMDUCTION joint between metacarpal 1 and
- Is a joint movement, involving carpals, allows thumb opposition.
flexion, extension, abduction,
and adduction, typically found in 11. OPPOSITION AND
ball and socket joints, with the distal REPOSITION
end moving in a circle. - Opposition involves thumb and
finger grasping, while reposition
6. ELEVATION AND DEPRESSION restores an object to its natural
- Elevation refers to movement above condition.
and below the horizontal, while
depression is movement in the
opposite direction, indicating a GROSS ANATOMY OF SKELETAL
downward movement. MUSCLES

1. HEAD MUSCLES
- The head muscles are an interesting
group because they have many
7. PROTRUSION/PROTRATION AND
specific functions but are usually
RETRUSION/RETRACTION
grouped into two large categories:
- Protraction and retraction refer
A. Facial muscles
to anterior and posterior movements
B. Chewing muscles
 - The trunk muscles include:
A. Those that move the vertebral
A. FACIAL MUSCLES
column
- Striated muscles that
B. Anterior thorax muscles, which
link the skin of the face to the bone
move the ribs, head, and arms and;
of the skull.
C. Muscles of the abdominal wall,
 Frontalis
which help to move the vertebral
 Orbicularis oculi
column and, most important, form
 Orbicularis orris
the muscular “natural girdle” of the
 Buccinator
abdominal body wall
 Zygomaticus

ANTERIOR VIEW OF TRUNK

B. CHEWING MUSCLES
MUSCLES
- The buccinator muscle, which is a
- The anterior trunk muscles, grouped
member of this group, is described
into the thoracic cage and abdominal
with the facial muscles.
wall muscles, cover the anterolateral
 Masseter
part of the trunk.
 Temporalis
 Lateral Pterygoid
POSTERIOR VIEW OF TRUNK
 Medial Pterygoid
MUSCLES
- The posterior trunk muscles, also
2. NECK MUSCLES
known as back muscles, are divided
A. ANTERIOR (FRONT)
into superficial and deep functional
- The anterior neck muscles, divided
groups.
into three subgroups, are primarily
superficial, including the platysma
MUSCLES OF UPPER LIMB
and sternocleidomastoid, which are
The upper limb muscles fall into
the most prominent in the neck.
three groups:
A. The first group arise from the
B. POSTERIOR (BACK)
shoulder girdle and cross the
- Splenius capitis and splenius cervicis
shoulder joint to insert into the
are strap like muscles in the back of
humerus
the neck that assist in extending a
B. The second group causes
rotating the head.
movement at the elbow joint
C. The third group includes the
C. LATERAL (SIDE MUSCLES)
muscles of the forearm
- The lateral neck muscles, Rectus
capitis anterior and Rectus capitis
lateralis, are responsible for
- All anterior arm muscles cause elbow
controlling head movements from
flexion. In order of decreasing strength,
the base of the skull.
these are the brachialis, biceps brachii,
and brachioradialis
3. TRUNK MUSCLES
 - Muscles that act on the lower limb - Orbicularis (circle)
cause movement at the hip, knee and foot - Latissimus (wide)
joints They are among the largest and
strongest muscle in the body and are 5. BY ACTION MUSCLE
specialized for walking and balancing the - Flexor (flexes bone)
body - Extensor (extends bone)
- Adductor (moves bone toward
- Part of the muscles of the lower limb
midline)
are the muscles at the hip joint.

- The posterior superficial muscles 6. BY LOCATION OF MUSCLE

include gluteal muscles and tensor fascia - Temporalis (temporal lobe)
latae, while the posterior deep muscles - Frontalis (frontal lobe)
include piriformis, obturator internus, - Anterior (front)
obturator internus, obturator externus,
superior gemellus, inferior gemellus, and 7. BY ORIGIN AND INSERTION
quadratus femoris - Sterno (sternum)
- Cleido (clavicle)

NAMING SKELETAL MUSCLES

ARRANGEMENT OF FASCICLES
1. BY DIRECTION OF MUSCLE
FIBERS 1. CIRCULAR
- Rectus (straight, along long axis) - Circular muscles are found around
- Transverse (perpendicular to long external body openings, typically
axis) arranged in concentric rings, and
- Oblique (at an angle) close by contracting

2. BY RELATIVE SIZE OF THE 2. CONVERGENT

MUSCLE - Convergent muscles involve fascicles
- Maximus (largest) convergent towards a single
- Minimus (smallest) insertion tendon, which can be
- Longus (longest) triangular or fan-shaped
- Brevis (shortest)
3. PARALLEL
3. BY NUMBER OF ORIGINS - The parallel arrangement of fascicles
- Biceps (2 heads) parallels the muscle’s long axis,
- Triceps (3 heads) creating straplike muscles. A
- Quadriceps (4 heads) modification called fusiform creates
4. BY SHAPE OF MUSCLE a spindle-shaped muscle with an
- Deltoid (triangular) expanded belly
- Trapezius (trapezoid-shaped)
- Serratus (saw-tooth) 4. PENNATE
- Rhomboid (rhombus-shaped)
 - The extensor digitorum muscle in
the leg has a pennate pattern, where 3. FIBULARIS MUSCLES
fascicles attach obliquely to a central - The fibularis muscles, longus bevis,
tendon, forming a unipennate and tertius, are located on the lateral
muscle leg and work together to flex and
evert the foot

MUSCLES CAUSING MOVEMENT AT 4. GASTROCNEMIUS

THE KNEE JOINT - A two-bellied muscle in the posterior
leg, is a key contributor to foot
1. HAMSTRING GROUP
plantar flexion
- The posterior thigh muscle mass
comprises three hamstring muscles:
5. SOLEUS
 Biceps femoris
- Originating from the tibia and fibula,
 Semimembranosus
is deep to gastrocnemius and does
 Semitendinosus
not impact knee movement

2. SARTORIUS
TYPES OF INJURIES THAT CAUSES
- Is the most superficial muscle of the
MUSCLE PAIN
thigh; it acts as a synergist to bring
about the cross-legged position - Abdominal strains
- Back strains or sprains
3. QUADRICEPS GROUP - Broken bones and traumatic injuries
- is responsible for extending the knee - Myofascial pain syndrome from
effectively by fleshing out the repetitive movements (overuse)
anterior thigh - Tendinitis
- Consisting of four muscles: - Tendinosis
 Rectus femoris
 Three vastus
OTHER CONDITIONS

MUSCLES CAUSING MOVEMENT AT - Cancers such as sarcoma—soft

THE ANKLE AND FOOT tissue cancers) and leukemia—blood
cancer)
1. TIBIALIS ANTERIOR
- Chronic fatigues syndrome
- Is a superficial muscle on the
- Compartment syndrome—buildup of
anterior leg, originating from upper
pressure in muscles
tibia and paralleling the anterior
- Fibromyalgia
crest as it runs to the tarsal bones
- Imbalance of electrolytes—minerals
2. EXTENSOR DIGITORUM LONGUS
in your blood, such as calcium,
- Originating from the lateral tibial
magnesium, sodium, potassium
condyle and proximal radius, is a key
- Hyperthyroidism—inactive thyroid
toe extension and foot dorsiflexor
 - Peripheral artery disease—PAD
- Stress and tension A. Visceral sensory receptors—
monitors internal organs

NERVOUS SYSTEM B. Somatic sensory receptors—

provide position, touch, pain, and
- A physically connected network of temperature sensations
cells, tissues and organs that allow
us to communicate with and react to
the environment and perform life C. Special sensory receptors—
activities provide sensations of smell, taste,
ORGANS vision, balance, and hearing

1. Brain 2. SENSORY DIVISON

2. Spinal Cord - Bring information of the peripheral
3. Nerves nervous system to the central
FUNCTIONS nervous system from receptors in
peripheral tissues and organs
- Sensing the world
- Processing information 3. INFORMATION PROCESSING
- Transmitting information - Includes the integration and
- Producing a response distribution of information in the
central nervous system

ANATOMY OF THE NERVOUS SYSTEM 4. MOTOR DIVISION

CENTRAL NERVOUS SYSTEM - Carries motor commands from of the
peripheral nervous system from the
- Consists of the brain and spinal cord central nervous system to peripheral
and is responsible for integrating, tissues and systems
processing, and coordinating sensory
data and motor commands A. Somatic nervous system—
controls skeletal muscle
contractions
PERIPHERAL NERVOUS SYSTEM B. Autonomic nervous system—
- Includes all the neural tissue outside provides regulation of smooth
the central nervous system muscle, cardiac muscle, glands,
and adipose tissue

1. RECEPTORS 5. EFFECTORS
- Are sensory structures that detect - Are target organs whose activities
changes in the internal or external change in response to neural
environment commands
 3. Microglia—spider-like cells that
clean up debris and dead cells in the
ORGANIZATION OF THE NERVOUS
nervous system
SYSTEM

STRUCTURAL CLASSIFICATION 4. Ependymal cells—line the brain

and spinal cord cavities, circulating
- Has two subdivisions:
cerebrospinal fluid to protect the
1. CENTRAL NERVOUS SYSTEM
central nervous system
A. Brain
B. Spinal cord
5. Oligodendrocytes—cells that
produce myelin sheaths insulating
C. PERIPHERAL NERVOUS
nerve fibers in the central nervous
SYSTEM
system
 All other nerves
6. Schwann cells—cells in the
peripheral nervous system that form
FUNCTIONAL CLASSFICATION
myelin sheaths around nerve fibers
- SENSORY DIVISION
- SOMATIC SENSORY FIBERS 7. Satellite cells—protective cells in
- VISCERAL SENSORY FIBERS the peripheral nervous system that
- MOTOR DIVISION support neuronal cell bodies
- SOMATIC NERVOUS SYSTEM
- AUTONOMIC NERVOUS SYSTEM Neurons (nerve cells)

- Highly specialized to transmit

NERVOUS TISSUE: STRUCTURE AND messages (nerve impulses) from one
FUNCTION part of the body to another

- Supporting cells in central nervous A. Cell body—the neuron’s metabolic

system are “lumped together” as center, containing a transparent
neuroglia—nerve glue nucleus. Nissi substance (rough ER)
and neurofibrils
B. Processes—armlike fibers with
1. Neuroglia—supportive cells in the varying lengths: dendrons carry
nervous system, each with specific messages toward the cell body, while
functions, including insulation and axons generate and conduct nerve
protection of neurons impulses away from the cell body
1. Axon hillock—cone-like region of
2. Astrocytes—star-shaped cells that the cell body where the axon
create a barrier between blood originates; neruons have one axon
vessels and neurons, aiding in and multiple dendrites
protection and nutrient exchange
 2. Axon terminals—endings of the 3. Interneurons—also called
axon containing tiny vesicles filled association neurons, they connect
with neurotransmitters sensory and motor neurons

3. Synaptic cleft—tiny gap between

axon terminals and the next neuron STRUCTURAL CLASSIFICATON

1. Multipolar neurons—the most

4. Myelin sheaths—fatty, whitish
common type with multiple
material covering long nerve fibers,
processes extending from the cell
providing insulation and increasing
body; found in motor and
the transmission speed of nerve
association neurons
impulses

2. Bipolar neurons—rare in adults,

5. Nodes of ranvier—gaps or
with two processes (an axon and a
indentions in the myelin sheath
dendrite); found in special sensory
along the axon, aiding in the rapid
organs for sensory processing
conduction of nerve impulses

3. Unipolar neurons—having a single,

short process emerging from the cell
TYPES OF NEURONS
body, which divides into proximal
1. Unipolar (central) and distal (peripheral)
2. Bipolar processes
3. Pseudounipolar
4. Multipolar
CENTRAL NERVOUS SYSTEM

- Receives, interprets, and sends

CLASSIFICATION OF NEURONS signals to peripheral nervous system
FUNCTIONAL CLASSIFICATION

1. Sensory neurons—afferent neurons BRAIN

carry impulses from sensory
1. CEREBRAL HEMISPHERE
receptors to the central nervous
system, keeping us informed about
A. Gyri—elevated ridges on the
the internal and external stimuli
surface of the cerebral
hemispheres separated by
2. Motor neurons—efferent neurons
shallow grooves called sulci
carrying impulses from the central
nervous system to muscles, glands,
B. Fissures—deeper groves, such as
and organs
the longitudinal fissure, separate
large brain regions:
 REGIONS OF THE CEREBRAL hemispheres, is known as
HEMISPHERE commissure
 Cerebral cortex—gray matter on
the surface responsible for E. Fiber tracts
speech, memory, sensation  Association fiber tracts—connect
interpretation, voluntary areas within a hemisphere.
movement, and more  Projection fiber tracts—connect
 Basal nuclei—islands of gray the cerebrum with lower central
matter deep within white matter, nervous system centers
regulating voluntary motor
activities 2. DIENCEPHALON

LOBES AND FUNCTIONS A. Thalamus—relays sensory

 Parietal lobe—contains the impulses to the sensory cortex,
primary somatic-sensory area for surrounding the third ventricle
interpreting sensory information
 Occipital lobe—contains visual B. Hypothalamus—regulates body
area temperature, water balance,
 Temporal lobe—contains the metabolism, and emotions, and
auditory and olfactory areas controls the pituitary gland; part
 Frontal lobe—contains the of the limbic system
primary motor area for voluntary
muscle movement C. Mammillary bodies—reflex
centers for the sense of smell,
TRACTS AND AREAS located on the floor of the
 Pyramidal tract—major motor hypothalamus
tract (corticospinal or pyramidal
tract) for muscle movement D. Epithalamus—forms the roof of
 Brocha’s area—involve speech, the third ventricle, housing the
located at the base of the pineal body (endocrine system)
precentral gyrus and choroid plexus (produces
 Speech area—located at the cerebrospinal fluid)
junction of temporal, parietal, and
occipital lobes for speech
processing

C. Cerebral white matter—is

3. BRAINSTEM
composed of fiber tracts
connecting various brain areas
A. Midbrain—extends from
mamillary bodies to pons contains
D. Corpus callosum—a large fiber
cerebral peduncles for ascending
tract connecting the cerebral
and descending impulses
 skeletal muscles and tendons,
B. Corpora quadrigemina—four and many other areas
protrusions on the dorsal
midbrain, reflex centers for vision
PROTECTION OF THE CENTRAL
and hearing
NERVOUS SYSTEM

C. Pons—below midbrain, fiber 1. MENINGES

tracts with nuclei for breathing - Dura mater
control - Falx cerebri
- Tentorium cerebelli
D. Medulla oblongata—the lowest - Arachnoid mater
part of the brain stem, regulates - Pia mater
vital functions like heart rate and
breathing 2. CEREBROSPINAL FLUID
- Clear fluid surrounds the brain and
E. Reticular formation—diffuse spinal cord, providing protection,
gray matter throughout the brain buoyancy, and nutrient exchange for
stem, including the reticular the nervous system
activating system for
consciousness and sleep/wake
cycle 3. BLOOD-BRAIN BARRIER
- Controls what substances can enter
the brain from the bloodstream,
4. CEREBELLUM maintaining the brain’s stability and
protecting it from harm
A. Structure—like the cerebrum,
the cerebellum has two
hemispheres and a convoluted SPINAL CORD
surface; it also has an outer
A. Length—about 17 inches (42 cm)
cortex made up of gray matter
long
and an inner region of white
matter
B. Function—two-way pathway to and
from the brain, and major center for
B. Function—provides precise
spinal reflexes
timing for skeletal muscle activity
C. Location—within the vertebral
and controls our balance and
column, from the skull to the first or
equilibrium
second lumbar vertebra
C. Coverage—fibers reach the
D. Meninges—protected by meninges,
cerebellum from the equilibrium
extending beyond spinal cord
apparatus of the inner ear, the
eye, the proprioceptors of the
 E. Spinal nerves—31 pairs of spinal B. Regions—divided into dorsal,
nerves exit the vertebral column to lateral, and ventral columns, each
serve nearby body areas containing specific fiber tracts

F. Cauda equina—collection of spinal C. Sensory tracts—transmit sensory

nerves resembling a horse’s tail at impulses to the brain; called sensory
the end of the vertebral canal afferent tracts

D. Motor tracts—carry impulses from

GRAY MATTER OF THE SPINAL CORD the brain to skeletal muscles; known
AND SPINAL ROOTS as motor or efferent tracts

A. Projections—posterior horns are

dorsal; anterior horns are ventral
PERIPHERAL NERVOUS SYSTEM

B. Central canal—surrounded by gray - Connects the central nervous system

matter, contains cerebrospinal fluid to all organ systems
- Made up of:
C. Dorsal root ganglion—houses A. Sensory neurons—detect stimuli
sensory neuron cell bodies from B. Motor neurons—carry the signal
dorsal roots to stimulate a response

D. Dorsal horns—contains - 2 motor subsystems:

interneurons A. Somatic—voluntary movement
 Sensory and motor nerves
E. Ventral horns—hold motor neuron  Reflex arc
cell bodies for the somatic nervous B. Autonomic—involuntary
system movement
 Sympathetic—fight or flight
F. Spinal nerves—formed by fusion of  Parasympathetic—relaxation
dorsal and ventral roots

WHITE GRAY MATTER OF THE SPINAL

STRUCTURE OF A NERVE
CORD
A. Endoneurium—delicate connective
A. Composition—the white matter of
tissue sheath surrounding each
the spinal cord consists of
nerve fiber
myelinated fiber tracts, conveying
impulses to and from various centers
 B. Perineurium—coarser connective
tissue wrapping that binds fibers into 5. Trigeminal nerve
fascicles - Emerges from pons, has three
divisions to face, conducts sensory
C. Epineurium—tough fibrous sheath- impulses from face skin and mouth,
binding fascicles together to form and has motor fibers for chewing
nerve cords muscles

D. Mixed nerves—nerves with both 6. Abducens nerve

sensory and motor fibers - Leaves pons, and supplies motor
fibers to lateral eye muscle (lateral
E. Sensory nerves—nerves carrying rectus)
impulses toward the central nervous
system only (afferent nerves) 7. Facial nerve
- Leaves pons to face, activates facial
F. Motor nerves—nerves carrying only muscles, lacrimal, and salivary
motor fibers (efferent nerves) glands, and carries taste impulses
from the anterior tongue

CRANIAL NERVES 8. Acoustic/Auditory nerve

- From inner ear to brain stem,
12 CRANIAL NERVES
sensory for balance (vestibular) and
(On Old Obando Tower Top A Filipino hearing (cochlear)
Army Guards Villages And Huts)
9. Glossopharyngeal nerve
1. Olfactory nerve
- From medulla to throat, motor fibers
- Arises from nasal mucosa, purely
to pharynx for swallowing, and
sensory for smell
carries taste and pressure impulses
2. Optic nerve
10. Vagus nerve
- Arises from the retina, purely
- From medulla to thorax and
sensory for vision
abdomen, sensory and motor for
pharynx, larynx, and viscera, with
3. Oculomotor nerve
parasympathetic fibers for digestion
- Runs from midbrain to eye, supplies
and heart
motor fibers for eye muscles and
eyelid, and internal eye muscles
11. Accessory (spinal)
controlling lens and pupil
nerve
- From medulla to neck and back
4. Trochlear nerve
muscles, mostly motor for
- Runs from the midbrain to the eye,
sternocleidomastoid and trapezius
and supplies motor fibers for one
eye muscle (superior oblique)
 12. Hypoglossal nerve AUTONOMIC NERVOUS SYSTEM
- From medulla to the tongue, motor
A. Composition—is composed of a
for tongue movements and sensory
specialized group of neurons that
from the tongue
regulate cardiac muscle, smooth
muscles, and glands

SPINAL NERVES AND NERVE

B. Function—at every moment, signals
PLEXUSES
flood from the visceral organs into
A. Rami—spinal nerves quickly divide the central nervous system, and the
into dorsal and ventral rami, each autonomic nerves make adjustments
about ½ inch long, containing both as necessary to best support body
sensory and motor fibers activities

B. Dorsal rami—smaller, serving skin C. Divisions—the autonomic nervous

and muscles of the posterior body system has two arms:
trunk  Sympathetic division
 Parasympathetic division
C. Ventral rami—t1-t2 forms
intercoastal nerves, supplying
muscles between ribs and ANATOMY OF THE PARASYMPATHETIC
anterior/lateral trunk DIVISION
A. Preganglionic neurons—are in the
D. Cervical plexus—originating from brain nuclei of cranial nerves 3, 7, 9,
c1-c5, includes the phrenic nerve for and 10 (especially the vagus) and
the diaphragm, shoulder, and neck s2-s4 spinal cord levels

E. Brachial plexus—axillary nerve for B. Craniosacral division—where

shoulder muscles/skin. Radial nerve cranial region neurons send axons
for triceps/forearm extensor/skin. via cranial nerves to head and neck
Median nerve for forearm organs
flexors/hand muscles/skin,
C. Pelvic splanchnic nerves—
musculotaneous nerve for arm
preganglionic axons from the sacral
flexors/lateral forearm skin, and
region form pelvic splanchnic nerves,
ulnar nerve for forearm/hand
travelling to the pelvic cavity
muscles/skin
F. Lumbar plexus—femoral nerve for ANATOMY OF THE SYMPATHETIC
abdomen/thigh muscles/skin, DIVISION
obturator nerve for thigh A. Ramus communicans—
muscles/skin preganglionic axons leave the spinal
cord, and pass through ramus
G. Sacral plexus—sciatic nerve communicans to enter the
sympathetic region
 E. Repolarization—potassium ions
B. Sympathetic chain—runs alongside exit, restoring negative inside and
vertebral column positive outside; repolarization
follows depolarization direction
C. Splanchnic nerves—axons may
synapse in the sympathetic chain or
COMMUNICATION OF NEURONS AT
pass through to form splanchnic
SYNAPSES
nerves
A. Arrival—the action potential arrives
D. Collateral ganglion—splanchnic at the axon terminal
nerves reach the viscera, and
synapse in the collateral ganglion B. Fusion—the vesicle fuses with the
plasma membrane

PHYSIOLOGY OF THE NERVOUS C. Release—neurotransmitter is

SYSTEM released into the synaptic cleft
Nerve impulses—electric and chemical
D. Binding—the neurotransmitter binds
wave along a nerve fiber that stimulates
to a receptor on the receiving
muscle, gland, or nerve cell
neuron’s end
Pathway:
E. Opening—the ion channel opens
A. Resting conditions—membrane
slightly positive outside, negative
F. Closing—once the neurotransmitter
inside; sodium outside, potassium
is broken down and released, the ion
inside; permeable to both
channel closes

B. Stimulus and depolarization—

stimulus alters permeability, and AUTONOMIC FUNCTIONING
sodium influx changes polarity
A. Antagonist effect—when both
(inside more positive, outside more
divisions serve the same organ, they
negative)
cause antagonist effects, mainly
because their postganglionic axons
C. Action potential generation—
release different transmitters
strong stimulus leads to complete
polarity reversal, initializing action
B. Cholinergic fibers—releases
potential
acetylcholine

D. Propagation—depolarization in one
C. Adrenergic fibers—releases
area triggers adjacent changes,
norepinephrine
rapidly propagating the action
potential along the entire length
D. Preganglionic axons—releases
acetylcholine of both divisions
SYMPATHETIC DIVISION  digestive tract actively processing
food
A. The fight or flight system
 skin warm (no need to divert
food)
B. Signs of the activity:
 Pounding heart
D. Optical state
 Rapid and deep breathing
 Eye pupils constricted to protect
 Cold and sweaty skin
retinas from excessive light
 Prickly scalp
 Eye lenses set for close vision
 Dilated pupils

C. Effects
NERVOUS SYSTEM DISEASES AND
 Increases heart rate, blood
DISORDERS
pressure, and blood glucose
 Dilates bronchioles in lungs - Epilepsy
 Helps cope with stressors - Bell’s palsy
- Parkinson’s disease
D. Duration—effects last several - Alzheimer’s disease
minutes until hormones are broken - Cerebral palsy
down by the liver - Multiple sclerosis
- Neurofibromatosis
E. Function - Migraine
 provides optimal conditions for - Meningitis
responding to threats - Rabies
 enables actions like running,
enhanced vision, and clearer
thinking in response to stressors

PARASYMPATHETIC DIVISION
A. Most active during rest, not
threatened

B. Function
 Promotes normal digestion
 Facilitates elimination of waste
 Conserves body energy
 Reducing demands on the
cardiovascular system

C. Relaxed state
 regulates blood pressure, heart,
and respiratory rates at normal
levels