The Human
Organism
Prepared by: Ferlynsis H. Estrada, LPT
Source: Regan., Russo., & VanPutte, Seeley’s Essential of Anatomy & Physiology: Mc Graw-Hill Education International Edition
Anatomy
Human anatomy and
physiology is the study of the
structure and function of the human
body.
Anatomy is the scientific
discipline that investigates the
structure of the body.
The word anatomy means to
dissect, or cut apart and separate,
the parts of the body for study.
Anatomy
Systemic anatomy is the
study of the body by systems,
such as the cardiovascular,
nervous, skeletal, and muscular
systems.
Regional anatomy is the
study of the organization of the
body by areas.
Anatomy
Surface anatomy is the study
of external features, such as bony
projections, which serve as
landmarks for locating deeper
structures.
Anatomical Imaging involves
the use x-rays, ultrasound,
magnetic resonance imaging or
MRI
Physiology
Physiology is the scientific
discipline that deals with the
processes or functions of living
things.
Physiology
Major Goals of Physiology
to understand and predict the
body’s response to stimuli
to understand how the body
maintain conditions with in narrow
range of values in the presence of
continually changing internal and
external environment.
Structure and Functional
Organization of the
Human Body
Chemical Level
Atoms combine to form
molecules, where in, its function
is intimately related to its
structure
Structure and Functional
Organization of the
Human Body
Cell level
Molecules form organelles,
such as the nucleus and
mitochondria, which make up
cells.
Structure and Functional
Organization of the
Human Body
Tissue level
Similar cells and
surrounding materials make
up tissues
Structure and Functional
Organization of the
Human Body
Organ level
Different tissues combine to
form organs, such as the
urinary bladder
Structure and Functional
Organization of the
Human Body
Organ System level
Organs, such as the urinary
bladder and kidneys, make
up an organ system
Structure and Functional
Organization of the
Human Body
Organism level
Organ systems make
up an organism
Characteristics of Life
Six Essential Characteristics
of Life
Organization refers to the specific
interrelationships among the parts of
an organism and how those parts
interact to perform specific functions.
Characteristics of Life
Six Essential Characteristics
of Life
Metabolism is the ability to use
energy to perform vital functions,
such as growth, movement, and
reproduction.
Characteristics of Life
Six Essential Characteristics
of Life
Responsiveness is the ability of an
organism to sense changes in the
environment and make the
adjustments that help maintain its
life.
Characteristics of Life
Six Essential
Characteristics of Life
Growth refers to an increase in
size of all or part of the organism.
Characteristics of Life
Six Essential Characteristics
of Life
Development includes the
changes an organism
undergoes through time; it
begins with fertilization and
ends at death.
Characteristics of Life
Six Essential Characteristics of
Life
Reproduction is the formation of
new cells or new organisms.
Homeostasis
is the existence and
maintenance of a relatively
constant environment within the
body despite fluctuations in
either the external environment
of the internal environment.
Organs System
of the Body
Homeostatic
Mechanism
Prepared by: Ferlynsis H. Estrada, LPT
Source: Regan., Russo., & VanPutte, Seeley’s Essential of Anatomy & Physiology: Mc Graw-Hill
Education International Edition
Homeostatic Mechanism
such as sweating or
shivering, normally maintain
body temperature near an
ideal normal value, or set
point.
Negative Feedback Mechanism
Three components of
Negative Feedback
Mechanism
Receptor – monitors the
value of the variable such
as body temperature
Control Center – such as
part of the brain ,
establishes the set point
around which the variable is
maintained.
Effector – such as sweat
gland, can change the value
of the variable
Stimulus is a changed variable
because it initiates a
homeostasis mechanism.
Negative-Feedback
Control of the
Body Temperature
Comparison of Negative-back and
Positive-feedback mechanism
Positive Feedback Mechanism
• It occurs when the initial stimulus further
stimulates the response. In other words, the
deviation from the set point becomes even
greater.
• Examples
• During blood loss
• Birth
Activity 1
Is the sensation of thirst associated with
a negative-or a positive feedback
mechanism? Explain
Terminology and the Body Plan
Body Positions
anatomical position refers to a person standing erect with the face
directed forward. The upper limbs hanging to the sides, and the
palms of the hands facing forward. A person is supine when lying
face upward and prone when lying face downward.
Up – superior
Down – inferior
Front – anterior/ventral
Back – posterior/dorsal
Nearest – proximal
Distant – distal
Midline – medial
Away from midline – lateral
Close to the surface – superficial
Interior of the body – deep
Body Parts and Regions
• Central Region (head, neck, and trunk)
• Trunk can be divided in to two: thorax (chest), abdomen
(region between thorax and pelvis)
• Upper limb (arm, forearm, wrist and hand).
• The arm extends from the shoulder to the elbow, and the
forearm extends from the elbow to the wrist.
• Lower limb (thigh, leg, ankle, and foot).
• The thigh extends from the hip to the knee, and the leg
extends from the knee to the ankle.
Body Parts and Regions
• Abdomen is often
subdivided superficially
into four section or
quadrants.
• In addition these
quadrants, the
abdomen is sometimes
subdivided into regions
by four imaginary lines.
Planes
Sagittal plane runs vertically
through the body and separates it
into right and left parts.
Median plane is a sagittal plane
that passes left halves.
Transverse plane or horizontal
plane runs parallel to the surface
of the ground, dividing the body
into superior and inferior parts.
Frontal plane or coronal
plane, runs vertically from right to
left and divides the body into
anterior and posterior parts.
Planes
Longitudinal section, a cut through the long
axis of the organ
transverse or cross section, a cut at a right
angle to the long axis
Oblique section, if a cut is made across the
long axis at other than a right angle
Body Cavities
The body contains many cavities. Some of these cavities, such as the nasal
cavity, open to the outside of the body, and some do not.
The trunk contains contain three large cavities that do not open to the outside
of the body: thoracic cavity, abdominal cavity and the pelvic cavity.
Thoracic cavity – is surrounded by the rib cage and is separated from the
abdominal cavity by the muscular diaphragm. It is divided into right and left
parts by a median structure called the mediastinum. The mediastinum is a
partition containing the heart, the thymus, the trachea, the esophagus, and
other structures. The two lungs are located on each side of the mediastinum.
Abdominal cavity – is bounded primarily by the abdominal muscles and
contains the stomach, the intestines, the liver, the spleen, the pancreas, and
the kidneys.
Pelvic cavity – is a small space enclosed by the bones of the pelvis and
contains the urinary bladder, part of the large intestine, and the internal
reproductive organ.
Body Cavities
Serous Membranes
Serous membranes line the trunk cavities and cover the organs of
these cavities.
Serous Membranes
The thoracic cavity contains three serous membrane-lined cavities: a
pericardial cavity and two pleural cavities.
Pericardial cavity surrounds the heart. Visceral pericardium covers the
heart, which is contained within a connective tissue sac lined with the
parietal pericardium. The pericardial cavity, which contains pericardial fluid,
is located between the visceral pericardium and the parietal pericardium.
Pleural cavity surround each lung, which is covered by visceral pleura.
Peritoneal Cavity a serous membrane-lined cavity contained in abdominal
peritoneal.
Pericarditis – inflammation of the pericardium
Pleurisy – inflammation of pleura
Peritonitis – inflammation of the peritoneum.
Serous Membranes
