Human Anatomy &
Physiology
Chapter 1: Introduction
Panda Wilson
1
II. Introduction
A. The beginnings of the study of human anatomy and
physiology were most likely concerned with treating illnesses
and injuries that interrupted a person’s ability to function.
B. Early healers began by relying heavily on superstition &
magic. But, as they begin to try to heal their patients, they
observed the effects of injuries and how wounds healed. Their
observations & investigations would have included examining
the bodies of the dead. Certain potions & herbs were
discovered that could be used to treat common symptoms of
illnesses. So observation led to experimentation – TA DA –
modern science! 
Panda Wilson
2
III. Anatomy & Physiology
Useful Information
• Anatomy deals with the structure (morphology) of the body and its
parts.
• Physiology studies the functions of these parts
• Anatomists rely on observation while physiologists employ
experimentation
• Function of a part depends on construction
Panda Wilson
3
III. Anatomy & Physiology
Anatomy (structure) is related to Physiology (function):
A. The function of the hand is to grasp & manipulate objects of various
sizes:
• the structure of the fingers allow flexion & extension, enabling them to wrap
around an object in order to grasp it
• the joints of the thumb allow rotation as well as flexion & extension
permitting the thumb to oppose the other fingers; this allows a pincer grasp
B. New discoveries are more likely in physiology since it depends more
on the development of scientific disciplines such as biochemistry
and molecular sciences.
Panda Wilson
4
IV. Levels of Organization
Panda Wilson
5
V. 1.3 Characteristics of Life
A. The following are characteristics shared by all organisms:
• Movement – change in the position of the body or of a body part;
may be internal or gross
• Responsiveness – reaction to an external or internal change
• Growth - an increase in body size without a change in shape
• Reproduction – production of new cells or new organisms
• Respiration – to obtain oxygen (O2), to release carbon dioxide
(CO2), and to release energy from food
• Digestion – to break down food substances into simpler forms that
can be absorbed & used
Panda Wilson
6
V. 1.3 Characteristics of Life
A. The following are characteristics shared by all organisms:
• Absorption – to move substances through membranes and into
body fluids
• Assimilation – to change absorbed substances into chemically
different forms
• Circulation – to move substances from place-to-place in body
fluids
• Excretion – to remove wastes produced by metabolic reactions
B. Metabolism
Panda Wilson
7
V. 1.3 Characteristics of Life
B. Metabolism is the sum total of chemical reactions in the
body. Includes reactions that breakdown substances
(catabolism) and those that build substances (anabolism).
Panda Wilson
8
VI. Maintenance of Life
A. Life depends on the availability (quantity &
quality) of the following
1. Water is required for metabolic reactions, for
transport of
substances, for temperature regulation
2. Food supplies nutrients necessary for energy and raw
materials for building new living matter
3. Oxygen is used in chemical reactions that release energy from
nutrients
4. Heat is a by-product of metabolism; its presence governs the
rate at which reactions occur
5. Pressure is a compressing force required to facilitate
movement of air or fluids
Panda Wilson
9
VI. Maintenance of Life
B. Vital signs (temperature, pulse, respiration, & blood
pressure) indicate that a person is alive. Vital signs can also
be helpful in forming a diagnosis on a patient.
Panda Wilson
10
VI. Maintenance of Life
C. Homeostasis
1. Maintenance of a stable internal environment is called
homeostasis.
• Receptors provide information about the internal
environment
• A set point is the value to be maintained
• Effectors produce changes necessary to maintain the set
point value
Panda Wilson
11
VI. Maintenance of Life
C. Homeostasis
2. The set point for a human’s body temperature is 98.6°F.
• If body temperature falls below the set point receptors sense the
drop in temperature and effectors are stimulated to increase
metabolic processes so that more heat is produced until the body
temperature reaches the set point.
• If body temperature increases above the set point receptors sense
the elevation in temperature and effectors are stimulated to
increase vasodilation (blood moves to the surface of the skin and
heat is lost to the environment, body temperature falls) and sweat
glands are stimulated to produce sweat (evaporation of sweat
from the skin's surface causes an additional drop in temperature).
Panda Wilson
12
VI. Maintenance of Life
C. Homeostasis
3. Negative feedback vs Positive feedback
• In a negative feedback system, the deviation from the set point
causes a response which leads to a return to the set point
(reducing the difference / deviation between the set point & the
actual condition of the body)
 for example: body temperature
• A positive feedback system causes the deviation between set point
and actual to increase.
 For example: nursing an infant – a loss of milk to a nursing infant leads to an increase in
milk production
Panda Wilson
13
VII. Organization of the Human Body
Axial vs Appendicular:
• The appendicular portion of the human body consists
of the appendages: upper & lower limbs (arms & legs)
• The axial portion of the human body includes the
head, neck, & trunk.
Panda Wilson
14
VII. Organization of the Human Body
A. The axial portion of the body contains 4 major cavities and 4 smaller
cavities of the head.
4 Major Cavities:
1. Cranial cavity – contains the skull / brain
2. Vertebral canal which contains the spinal cord & the vertebrae
3. Thoracic cavity – contains the heart & lungs
4. Abdominopelvic cavity – which is further divided into an upper
abdominal cavity and a lower pelvic cavity
Panda Wilson
15
The Axial Portion of the Human Body
Panda Wilson
16
VII. Organization of the Human Body
B. 1. The thoracic cavity
• is divided by the mediastinum into right and left cavities which
contain the right & left lungs;
• the mediastinum contains the heart, esophagus, trachea, & the
thymus gland.
• The thoracic cavity is separated from the abdominopelvic cavity by
a broad, thin muscle called the diaphragm.
Panda Wilson
17
VII. Organization of the Human Body
B. 2. The abdominopelvic cavity
• The upper abdominal cavity contains the following viscera:
stomach, liver, gallbladder, kidneys, and most of the small &
large intestines
• The lower pelvic cavity contains the following viscera:
the terminal portions of the large intestines, urinary bladder,
and internal reproductive organs
Panda Wilson
18
VII. Organization of the Human Body
C. The four smaller cavities of the body are found in the head:
1. Oral cavity – contains the teeth & tongue
2. Nasal cavity - within the nose; contain the sinuses (air-filled
chambers);
3. Orbital cavities – contain the eyes and associated skeletal muscles &
nerves;
4. Middle ear cavities – contain the middle ear bones.
Panda Wilson
19
VII. Organization of the Human Body
D. Thoracic & Abdominopelvic Membranes
Parietal membrane refers to membranes attached to the wall
of a cavity.
Visceral membrane refers to the deeper membrane that
covers an internal organ
Panda Wilson
20
VII. Organization of the Human Body
D. Thoracic & Abdominopelvic Membranes
1. Membranes of the thoracic cavity are called pleura:
a. The walls of the thoracic cavity are lined with
membranes referred to as the parietal pleura.
b. The lungs are covered by visceral pleura.
c. The parietal & visceral pleura are separated by a
“potential” space called the pleural cavity (there is no
actual space because the area is filled with a thin,
watery fluid called the serous fluid)
Panda Wilson
21
VII. Organization of the Human Body
D. Thoracic & Abdominopelvic Membranes
2. The heart is located in the mediastinum of the thoracic cavity
and is surrounded by pericardial membranes.
• The walls of the mediastinum is covered by a thick parietal
pericardium;
• The surface of the heart is covered by a thinner visceral
pericardium.
• The parietal & visceral pericardium are separated by a
“potential” space called the pericardial cavity that contains
small amount of serous fluid
Panda Wilson
22
VII. Organization of the Human Body
D. Thoracic & Abdominopelvic Membranes
3. In the abdominopelvic cavity the lining membranes are
called peritoneal membranes.
• A parietal peritoneum lines the walls of the cavity
• The surface of each organ is covered by a visceral
peritoneum.
• The parietal & visceral peritoneum are separated by a
“potential” space called the peritoneal cavity
Panda Wilson
23
VII. Organization of the Human Body
E. Organ systems
1.Integumentary system
2. Skeletal system
3. Muscular system
4. Nervous system
5. Endocrine system
6. Cardiovascular system
7. Lymphatic system,
8. Digestive system
9. Respiratory system
10. Urinary system
11.Reproductive system
Panda Wilson
24
Integumentary System Function:
Body Covering
Body Covering
The integumentary system (including skin, hair, nails, and
various glands):
• covers the body,
• senses changes outside the body,
• and helps regulate body temperature.
Panda Wilson
25
Skeletal & Muscular System Function:
Support & Movement
a. The skeletal system is made up of bones and ligaments. It
supports, protects, provides frameworks, stores inorganic
salts, and houses blood-forming tissues;
b. The muscular system consists of the muscles that cause
body movement, maintain posture, and is the main source
of body heat.
Panda Wilson
26
Nervous & Endocrine System Function:
Integration & Coordination
a. The nervous system consists of the brain, spinal cord,
nerves, and sense organs. It integrates incoming
information from receptors and sends impulses to muscles
and glands. (Sense & Respond)
b. The endocrine system (including all of the glands that
secrete hormones), helps to integrate metabolic functions
by secreting chemical messengers called hormones.
Panda Wilson
27
Cardiovascular& Lymphatic System Function:
Transport
a. The cardiovascular system, made up of the heart and
blood vessels, distributes oxygen and nutrients throughout
the body while removing wastes from the cells.
b. The lymphatic system, consisting of lymphatic vessels,
lymph nodes, thymus, and spleen, drains excess tissue fluid
and includes cells of immunity that help protect the body
from pathogens.
Panda Wilson
28
Digestive, Respiratory, & Urinary System Function:
Absorption & Excretion
a. The digestive system is made up of the mouth, esophagus,
stomach, intestines, and accessory organs. It receives
food, breaks it down, absorbs nutrients, & excretes waste.
b. The respiratory system (lungs, respiratory passages, nose,
& pharynx) exchanges gases between the blood & air.
c. The urinary system (consisting of the kidneys, ureters,
bladder, & urethra) removes wastes from the blood and
helps to maintain fluid and electrolyte balances.
Panda Wilson
29
Reproductive System Function:
Reproduction
The reproductive system produces new organisms.
a. The male reproductive system consists of the testes,
accessory organs, and vessels that produce sperm &
conduct it to the penis.
b. The female reproductive system consists of ovaries, uterine
tubes, uterus, vagina, and external genitalia. The female
reproductive system produces ova & also houses the
developing offspring.
Panda Wilson
30
Anatomical Terminology
• Relative Positions:
1. Terms of relative position are used to describe the location of
a part relative to another part.
2. Terms of relative position include:
• superior, inferior, anterior, posterior, medial, lateral, proximal, distal,
superficial (peripheral), and deep.
Panda Wilson
31
Body Sections
1. A sagittal section divides the body into right & left portions.
2. A transverse section divides the body into superior &
inferior portions. It is often called a “cross section”.
3. A coronal section divides the body into anterior & posterior
sections.
Panda Wilson
32
CopyrightThe McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Body Sections, cont
Sometimes a cylindrical organ (a long bone, the trachea),
in such cases:
1. A cut across the structure is called a cross-section.
2. An angular cut across the structure is called an oblique
section.
3. A lengthwise cut on the structure is called a longitudinal
section.
Panda Wilson
34
CopyrightThe McGraw-Hill Companies, Inc. Permission required for reproduction or display.
• Body Regions
1. The abdominal area can be divided into
nine regions.
2. Terms used to refer to various body
regions are depicted in Fig. 1.15.