The Need to Have a Control System
Nervous System Overview:
- Primary Control Center: The nervous system gathers sensory information,
processes it, and initiates responses. It helps maintain homeostasis and
allows interaction with the environment.
- Voluntary vs. Involuntary Movements: Voluntary movements are controlled
by conscious thought, while involuntary movements (e.g., reflexes) happen
automatically.
Communication and Neurons:
- Electrical Impulses: Neurons communicate using electrical impulses, which
are fast and short-lived.
- Neuron Structure: Key parts include dendrites (receive signals), axon (sends
signals), and myelin sheath (insulates and speeds up impulse transmission).
- Types of Neurons:
There are three types:
Sensory Neurons(detect stimuli),
Interneurons (process signals),
Motor Neurons (relay responses to muscles).
Nervous System Components:
- Central Nervous System (CNS): Composed of the brain and spinal cord,
it acts as the body’s command center.
- Peripheral Nervous System (PNS): Connects the CNS to the body’s
organs and is divided into the Autonomic (involuntary control) and Somatic
(voluntary control) systems.
Reflex and Synapse:
- Reflex Arc: An automatic, quick response to a stimulus (e.g., removing
your hand from a hot surface).
- Synapse: The small gap between neurons where impulses are transferred
via chemical neurotransmitter.
Brain Structure and Functions:
- Cerebrum: The largest part of the brain responsible for reasoning,
movement, and sensory processing.
- Limbic System: Involved in emotions and memory. Key components
include the amygdala (emotion) and hippocampus (memory).
- Brain Stem: Controls vital functions like breathing and heartbeat.
Here is a reviewer for the Sensory System from your PowerPoint presentation
for the summative test:
Sensory System Overview:
- Receptors: Specialized neurons that respond to different stimuli.
- Sense Organs: These structures carry messages about the surroundings
to the Central Nervous System (CNS).
Types of Senses:
1. General Senses
- Somatic Senses. Respond to heat, pressure, pain, and changes in body
position.
- Visceral Senses. Provide information about internal organs.
2. Special Receptors. Respond to light, vibrations, and chemicals. Found in
specific areas.
Four-Way Process of Sensory Perception:
1. Stimulation. A physical stimulus activates a sensory receptor.
2. Transduction. The stimulus is converted into an electrical signal (action
potential).
3. Transmission. Nerve impulses are conducted to the CNS.
4. Interpretation. The brain processes the signal to create perception.
Mechanical Stimuli – Mechanoreceptors:
- Hearing: Sound waves travel from the ear canal to the organ of Corti in the
cochlea, where hair cells are activated, sending signals to the brain.
- Balance: The vestibular system in the inner ear detects movement (linear
and angular) through the utricle, saccule. and semicircular canals to help
maintain balance.
Chemical Stimuli – Chemoreceptors:
- Smell (Olfaction): Odorants bind to olfactory receptors in the nasal cavity,
sending signals to the brain areas involved in memory and emotion.
- Taste (Gustation): Taste buds detect chemicals from food, generating
nerve impulses that are sent to the brain.
- Interconnection of Smell and Taste: These senses work together to
create flavor perception. Impairments in smell can affect taste.
Electromagnetic and Thermal Energy Stimuli:
- Vision. Light is detected by photoreceptors (rods and cones) in the retina.
Visual information is then processed by the brain, allowing us to see.
- Rods: Responsible for peripheral and night vision.
- Cones: Enable daytime and color vision.
Somatosensation – Touch and Body Sensations:
- Tactile Receptors. Detect light touch, texture, and small movements.
- Proprioceptors. Respond to deep pressure and body position.
- Thermoreceptors. Detect temperature changes.
- Nociceptors. Pain receptors alert the body to harm.
- Baroreceptors. Monitor pressure changes inside internal organs.
The Need to Regulate and Maintain Internal Body Processes
Endocrine System
- produce hormones
- long-term changes
- growth and development
- most are slow-acting yet the effect is long-loved
- hormones are produced in the glands
- keep all body parts smoothly
- endo means within
- transport of hormones in the blood stream
- ductless glands
1) Hypothalamus
- located deep within the brain
- control center of the endocrine
- regulates many body processes
Growth Hormone Releasing Hormone (GHRH)
Thyrotropin Releasing Hormones (TRH)
Corticotropin Releasing Hormone (CRH)
Gonadotropin Releasing Hormone (GnRH)
Oxytocin – happy hormone, cervix dilation in giving birth
Vasopressin (Antidiuretic Hormone) – water
Dopamine – happy hormone
Somatostatin –
2) Pituitary Gland
- master gland
- mainly for the growth
- below the hypothalamus
- mainly produce growth hormone
Growth Hormone
Thyroid – Stimulating Hormone (TSH)
Adrenocorticotropic Hormone (ACTH)
Follicle – Stimulating Hormone (FSH)
3) Thyroid Gland
- regulate metabolism
- located in the neck
- energy levels, body temp, calcium levels
- hyperthyroidism, hypothyroidism
Triiodothyronine (T4)
Thyroxine (T4)
Calcitonin – calcium levels
4) Parathyroid Glands
- regulates calcium level in blood
- behind Thyroid Gland
Parathyroid Hormone (PTH)
5) Adrenal Glands
- top of kidney
- fight or flight response
- blood pressure and metabolism
Adrenaline (Epinephrine) – both neurotransmitter and hormone, fight-or-
flight, adrenaline rush
Cortisol – stress hormone
Aldosterone – salt and water balance, blood pressure
Dehydroplandosterone
6) Pineal Glands
- center of the gland
Melatonin – sleep-wake cycle, biological clock
7) Pancreas
- behind the stomach
- regulate blood sugar levels
- both exo and endo
Insulin – decreases blood sugar levels
Glucagon – increases blood sugar levels
Vasoactive Intestinal Peptide (VIP)
Somatostatin
8) Ovaries (FEMALES)
- release egg cells
Estrogen
Progesterone
Testosterone
Anti Mullerian Hormone (AMH)
Inhibin A and Inhibin B
9) Testes (MALES)
-two glands located in the scrotum
-produce sperm and hormones involved in puberty
Testosterone – male sexual characteristics
Anti Mullerian Hormone (AMH)
Estradiol – small amounts of estrogen
Inhibin B – regulates FSH
Other organs that produce hormone
-brain, stomach, small intestine
Hormones are classified as
1) Peptide (peptide, proteins, glycoproteins, modified amino acid – building
block of proteins)
2) Steroids (Lipids/fats derived from Cholesterol)
-Hormone binds to a specific target cells
-Only affects a target organ
-hormones travel thru the blood stream
Types of Hormones
1) Steroid Hormones
- lipid in nature
- fast diffusion
- fast to bind, into the membrane of target cell
2) Peptide Hormones
- cannot diffuse to the plasma membrane of the target cell
- bind to a receptor protein in the plasma membrane as initial messenger
Both the endocrine and nervous system interact to maintain homeostasis
and regulate the body.
Stimuli
Equilibrium
Homeostasis – way of maintaining a stable internal environment, adapting
to changes in the environment
The Collaborative Efforts of
1) Sensors (Receptors)
Specialized cells/ organs that monitor changes in the environment.
2) Control Center
3) Communication
Negative Feedback- high blood sugar prevent
Positive Feedback- produce
The Need for Extra Protection and Support
Integumentary
Integument – outer covering in animals
Skins, scales, feathers, hairs.
Skin – largest organ in the human body.
Whiskers – special tactile hairs that respond to touch, cats
Quills – of porcupines, serves protection against enemies and acts as
padding against blows, falling objects
Hairs of animals – used to manufacture coat
Bristles – hairs of pigs that are used for brushes
Horns, claws, talons – same as the nails of the human
Scales, Hard Shells, Hard Bony Plates
Human Skin – Layers
15% total body weight
1.4 – 1.9 sq. meters area
Largest Organ
3 kg more than twice as much as the brain
Skin is almost completely waterproof
Prevents escape of fluids
Helps keep internal temp to normal levels
Skin glands release sweat when warm
Narrowing blood vessels in skin - due to low heat
Layers of Tissue
Epidermis
Dermis
Subcutaneous or Hypodermis
1) Epidermis
- outermost layer
- thick as a sheet of paper
- made of several layers of epithelial cells
- Keratinocytes are new skin cells that form upward to produce keratin
- Keratin is a protein
- life span of skin cells is 14 days
- Keratin only found in epidermis
- Melanin gives skin color
- Melanocytes produce melanin
- Melanin absorbs UV radiation
- light skin more prone to skin cancer
2) Dermis
- middle layer
- 15 to 40 times think as the epidermis
- lies beneath the epidermis
- also known as the true skin
- connective tissues make up the dermis
- it makes the skin tough and elastic
- contains nerve cells, blood vessels, hair follicles, specialized skin cells
- sense of touch, temperature
- contains tiny muscles called arrector pili
- these are attached to hair follicles
- when cold or frightened, these muscles contract, pull the hair shafts upright
- this helps insulate the body
- it produces bumps around the hair
- goose bumps
- Thermoregulation maintains normal temperature in the body
- blood vessels dilate when releasing heat
- Perspiration is a process on removing body heat utilizing sweat glands
- 3rd degree burns are painless since sensory receptors are destroyed
3) Subcutaneous Tissue, Hypodermis
- much thicker than epidermis, dermis
- layers of connective tissues mostly fats
- store fats, energy
- shock absorber
- additional insulation
- anchors the skin to internal, underlying organs
- eyelids have thin subcutaneous tissue, buttocks and thighs have more
Differentiate The Layers of The Skin
Modifications of The Skin
Skin includes hairs, nails, glands
Hair Structure
Hair is dead keratin
1) Root Part – keratinization
2) Shaft – the protruding hair
- cuticle (outermost), cortex (melanin), medulla (innermost)
Nail – hard keratin
- Matrix (the source), plate (nail), bed (under the nail)
Two Kinds of Glands
1) Sebaceous Glands – produces sebum w/c softens hair, lubrication and
protection
2) Sweat Glands – maintain normal body temperature
Two Types of Sweat Glands
1) Eccrine Glands – throughout the body
2) Apocrine Glands – bad odor, hairs (genitals, armpits, scalp)
External Protection In Plants
Covering, Growth and Metabolism
Parenchyma – Ground Tissue
Dermal Tissue System
- Stems and leaves reduce water loss
Non-woody Plants (Herbaceous)
- epidermis
- secretes a waxy layer called “cuticle”
- greek word -epi, upon, -derma,
- hair-like structure in root, root hairs
Woody Plants
- periderm instead of epidermis
- dermal tissue in stems and roots have dead cells referred to as “cork”
- cork cells contain a waterproof chemical, not covered by cuticle
- utilized in gas exchange and absorption of nutrients
- cork cells have thick walls contains a waxy substance called suberin
- suberin
- lenticels
- cork ambium
- phloem
- bark
- inner bark
- outer bark
The Need to Provide Bodily Shape and Support for the Internal Organs
What, Types, Human System, Division
Skeletal System
- bones, cartilages, ligaments
- body structure, framework
- supports the body
- produces blood cells
- protects organs
- structure, movement, protection
Skeleton – framework of bones
Types of Skeletons
1) Hydrostatic
2) Exoskeleton
3) Endoskeleton
1) Hydrostatic
- fluid serves as framework or bone
- fluid-filled called Coelom (Se/Lum), or cavity
- found in soft bodied animals
- sea anemones, earthworms, cnidarias, other invertebrates
2) Exoskeleton
- external skeleton
- consist of hard encasement on the surface of the organism
- defense against predators, supports body, allows for movement thru
contraction of attached muscles
3) Endoskeleton
- internal skeleton
- hard, mineralized structure located within the organisms’ body
- support for the body
- protect internal organs
Worlds Largest Animal
Animal – Blue Whale
Land animal – African Bush Elephant
Tallest – Girrafes
Reptile – Saltwater Crocodile
Snake – anaconda
Marine animal
The weight of the exoskeleton hinders an organism’s ability to move.
Human Skeletal System
Internal Skeleton – supports and shapes human body
Skeleton – is the collection of bones
206 bones for adults
275 – 300 bones for infants
Bones – living tissues
Shape and Support
Protects Internal Organs
Attachment for Major Muscles
Bones
Produce blood cells in bone marrow
Stores Calcium and Phosphorus compounds
Axial Skeleton
80 bones
Skull ,ribs,
Appendicular
Limbs
Upper Extremity
- Humerus, radius, ulna, carpal, metacarpals, phalanges
Pelvic Girdle
- 2 hip bones
Lower Extremity
- Femur (thigh), patella, tibia, fibula, tarsal, metatarsals, phalanges
Bones
1) Long Bones
- hollow
- length exceeding width
- strong, lightweight
- support
2) Flat Bones
- thin, various parts of the body
- protection of vital organs
3) Short Bones
- relatively small, cube-shaped
- hands and feet
- support weight and precision
4) Irregular Bones
5) Sesamoid Bones
- small, rounded bones embedded in tendons
- assist proper functioning of muscles
- reduce friction
- pattela
Bone’s Journey
Bone
- Strong and rigid, collagen and calcium
Cartilage
Joints
- connections in bones
- ends of bone covered by cartilage
- synovial fluid lubricates
Cartilage
- soft bones
- smooth substance covering the ends of the bone
Synovial Fluid
- slippery fluid acting as lubricant
- reduce friction
- loss causes arthritis (inflammation)
Ligaments
- strong, stretchy bands
- bones to bones
Tendons
- Bones to muscle
Types of Joints
1) Immovable
- fixed, bones fused together by collagen
- merged bones
- collagen is a protein
- stability and protection
- minimal or no movement
2) Slightly Movable Joints
- connected by cartilage, slightly movable
- cartilaginous joints
- shock absorption
3) Freely Movable Joints
- allowing wide range of movement
Knee Joint
Bones, Ligaments, Cartilage
The Need to Move for Various Life Activities
Muscle
Muscle fibers
- organs made up of thousands of cells
- these shorten when muscle contracts
Types of Muscle Tissues
Cardiac – involuntary
Smooth – involuntary
Skeletal – voluntary, needs consciousness
600 muscles in our body
Muscles
- help maintain normal temperature
- allow for digestion
- allow movement
- hold the skeleton together
- affect the rate of blood flow
- allow to do various positions
3 Types of Muscles in a Human
Skeletal
Smooth
Cardiac
1) Skeletal Muscle
- voluntary, striped
- attached to bones
- leg muscle
2) Smooth Muscle
- involuntary
3) Cardiac Muscle
- involuntary
Myosin – thick filament
Actin – thin filament
Skeletal Muscles work in pairs
Muscular System In Plants
Plant Growth and Support
Translocation – process of transporting plant nutrients in the phloem
Open growth – growth pattern in plants
Meristems – regions in the plant where growth occurs
Meristematic Tissue – tips, branches, roots
1) Apical Meristems
- length, elongation, taller
- primary growth
- perpetual ones in tips of roots and stems
- produces primary xylem and phloem
2) Lateral Meristems
- increase in diameter, widen plants
- two main types
- a) Vascular Cambium
- secondary xylem, wood
- b) Cork Cambium
- protective lTropism – the process of growth
Positive Tropism –
Negative Tropism –
Photoreceptors – media for plants’ response to light, composed of protein-
bound to a light absorbing pigment
Phototropism – light
Heliotropism – sun
Gravitropism/ Geotropism – gravitational pull
Thigmotropism – touch, thigmomorphogenesis
Plant Hormones
- Organic compounds that regulate plants
Major Types of Hormones
Auxins
- greek word auxien, meanig to grow
- plasticity of plant cell walls
- plant growth
Gibberellins (GA)
- Upward growth against gravity
Cytokines
- promotes cytokinesis and cell division
- differentiation of meristems
Ethylene
- Fruit ripening, leaf abscission (shedding) and senescence, response to
stress
Abscisicic Acid
- Response to conditions such as cold temperature
Oligosaccharides
- Protection against fungal and bacterial infection
Jasmonates
- defense activities against herbivory
