Chapter 1
An Introduction
to the Structure and Function
of the Body
Mosby items and derived items © 2012 by Mosby, Inc., an affiliate of Elsevier Inc.
1
A&P
1. Anatomy
a. Gross/Macroscopic Anatomy
b. Systemic Anatomy
c. Developmental Anatomy
d. Microscopic Anatomy
• Cytology
• Histology
Mosby items and derived items © 2012 by Mosby, Inc., an affiliate of Elsevier Inc.
2
A&P
2. Physiology
a. Cell physiology
b. Organ physiology
c. Systemic physiology
!
3. Pathology -
!
4.Pathophysiology -
Mosby items and derived items © 2012 by Mosby, Inc., an affiliate of Elsevier Inc.
3
STRUCTURAL LEVELS OF ORGANIZATION
1.Organization is the most important characteristic of
body structure
2.The body as a whole is a unit constructed of the following smaller units (Figure 1-2):
Chemical level—atoms and molecules
➢ Organelles - subcellular organs
➢ Cells—the smallest structural units; organizations of
various chemicals
➢ Tissues—organizations of similar cells
➢ Organs—organizations of different kinds of tissues
➢ Systems—organizations of many different kinds of organs
➢
Mosby items and derived items © 2012 by Mosby, Inc., an affiliate of Elsevier Inc.
4
Organizing a Muscle
!
• Protein molecules
(chemical level)
• Protein filament
(organelle level)
• Muscle cells
(cellular level)
• Cardiac Muscle
(tissue level)
• Heart
(organ level)
!
!
Mosby items and derived items © 2012 by Mosby, Inc., an affiliate of Elsevier Inc.
5
Regulation of the Body
!
The body uses negative feedback loops and, less
often, positive feedback loops to maintain or restore homeostasis
➢ Feedback loops involve a sensor, a control center,
and an effector
➢
Mosby items and derived items © 2012 by Mosby, Inc., an affiliate of Elsevier Inc.
6
Mosby items and derived items © 2012 by Mosby, Inc., an affiliate of Elsevier Inc.
7
THE BALANCE OF BODY FUNCTIONS (cont.)
⬤
⬤
All organs function to maintain homeostasis
Ability to maintain balance of body functions is related to age; peak efficiency occurs during
young adulthood, diminishing efficiency of many
functions begins after young adulthood
Mosby items and derived items © 2012 by Mosby, Inc., an affiliate of Elsevier Inc.
8
ANATOMICAL POSITION
⬤
⬤
Reference position in which the body stands
erect with the arms at the sides and palms
turned forward (Figure 1-3)
Anatomical position gives meaning to
directional terms
Mosby items and derived items © 2012 by Mosby, Inc., an affiliate of Elsevier Inc.
9
Mosby items and derived items © 2012 by Mosby, Inc., an affiliate of Elsevier Inc.
10
ANATOMICAL DIRECTIONS
⬤
⬤
⬤
⬤
⬤
⬤
⬤
⬤
⬤
⬤
Superior—toward the head, upper, above
Inferior—toward the feet, lower, below
Anterior—front, in front of (same as ventral in humans)
Posterior—back, in back of (same as dorsal in humans)
Medial—toward the midline of a structure
Lateral—away from the midline or toward the side of a structure
Proximal—toward or nearest the trunk, or nearest the point
of origin of a structure
Distal—away from or farthest from the trunk, or farthest from a structure’s point of origin
Superficial—nearer the body surface
Deep—farther away from the body surface
Mosby items and derived items © 2012 by Mosby, Inc., an affiliate of Elsevier Inc.
11
PLANES OR BODY SECTIONS (Figure 1-4)
⬤
⬤
⬤
⬤
Sagittal plane—lengthwise plane that divides a structure into right and left sections
Midsagittal—sagittal plane that divides the body
into two equal halves
Frontal (coronal) plane—lengthwise plane that
divides a structure into anterior and posterior
sections
Transverse plane—horizontal plane that divides a structure into upper and lower sections
Mosby items and derived items © 2012 by Mosby, Inc., an affiliate of Elsevier Inc.
12
Mosby items and derived items © 2012 by Mosby, Inc., an affiliate of Elsevier Inc.
13
BODY CAVITIES (Figure 1-5)
⬤
Ventral cavity
➢
Thoracic cavity
• Mediastinum—midportion of thoracic cavity; heart
and trachea are located in mediastinum
• Pleural cavities—right lung located in right pleural
cavity; left lung is in left pleural cavity
Mosby items and derived items © 2012 by Mosby, Inc., an affiliate of Elsevier Inc.
14
Mosby items and derived items © 2012 by Mosby, Inc., an affiliate of Elsevier Inc.
15
BODY CAVITIES (cont.)
⬤
Ventral cavity (cont.)
➢
Abdominopelvic cavity
• Abdominal cavity contains stomach, intestines, liver,
gallbladder, pancreas, and spleen
• Pelvic cavity contains reproductive organs, urinary
bladder, and lowest part of intestine
• Abdominopelvic regions
– Four quadrants (Figure 1-6)
– Nine regions (Figure 1-7)
Mosby items and derived items © 2012 by Mosby, Inc., an affiliate of Elsevier Inc.
16
Mosby items and derived items © 2012 by Mosby, Inc., an affiliate of Elsevier Inc.
17
Mosby items and derived items © 2012 by Mosby, Inc., an affiliate of Elsevier Inc.
18
BODY CAVITIES (cont.)
⬤
Dorsal cavity
Cranial cavity contains brain
➢ Spinal cavity contains spinal cord
➢
Mosby items and derived items © 2012 by Mosby, Inc., an affiliate of Elsevier Inc.
19
BODY REGIONS (Figure 1-9)
⬤
⬤
⬤
Axial region—head, neck, and torso or trunk
Appendicular region—upper and lower extremities
Body structure and function varies among
individuals and also throughout an individual's
lifespan; atrophy (decrease in size) occurs when
an organ is not used
Mosby items and derived items © 2012 by Mosby, Inc., an affiliate of Elsevier Inc.
20
Mosby items and derived items © 2012 by Mosby, Inc., an affiliate of Elsevier Inc.
21