Chapter 1
Organization of the
Body
Slide
Mosby items and derived items © 2007, 2003 by Mosby, Inc.
1
Anatomy and Physiology
• Anatomy and physiology are branches of
biology concerned with the form and functions
of the body
• Anatomy - study of the structure of an
organism and the relationship of its parts
• Physiology – is the science that deals with the
functions of the living organism and its parts.
Slide
Mosby items and derived items © 2007, 2003 by Mosby, Inc.
2
Anatomy and Physiology
• Gross anatomy—study of the body and its parts
using only the naked eye (Figure 1-2)
• Microscopic anatomy—study of body parts
using a microscope
– Cytology—study of cells
– Histology—study of tissues
Slide
Mosby items and derived items © 2007, 2003 by Mosby, Inc.
3
Anatomy and Physiology
• Developmental anatomy—study of human
growth and development
• Pathological anatomy—study of diseased body
structures
• Systemic anatomy—study of the body
by systems
Slide
Mosby items and derived items © 2007, 2003 by Mosby, Inc.
4
Anatomy and Physiology
• Physiology—science of the functions of
organisms; subdivisions named according to
– Organism involved—human or plant physiology
– Organizational level—molecular or cellular
physiology
– Systemic function—respiratory, neurovascular, or
cardiovascular physiology
Slide
Mosby items and derived items © 2007, 2003 by Mosby, Inc.
5
Characteristics of Life
• Characteristics of life considered most
important in humans:
–
–
–
–
–
Responsiveness
Conductivity
Growth
Respiration
Digestion
–
–
–
–
–
Absorption
Secretion
Excretion
Circulation
Reproduction
Slide
Mosby items and derived items © 2007, 2003 by Mosby, Inc.
6
Characteristics of Life
• Responsiveness – permits an organism to sense,
monitor and respond to changes in its external
environment
– Example: withdrawing from a painful stimulus, i.e.
pinprick…
• Conductivity – capacity of living cells and
tissues to selectively transmit a wave of
excitation from one point to another
– Nerve impulse conduction
Slide
Mosby items and derived items © 2007, 2003 by Mosby, Inc.
7
Characteristics of Life
• Growth – result of a normal increase in the size
or number of cells
– Hypertrophy or Hyperplasia
• Respiration – processes that result in the
absorption, transport, utilization, or exchange of
respiratory gases
– O2/CO2 exchange in the lungs
Slide
Mosby items and derived items © 2007, 2003 by Mosby, Inc.
8
Characteristics of Life
• Digestion – process by which complex foods are
broken down into simpler substances that can
be absorbed by the bodies cells
– Catabolism
• Absorption – movement of digested nutrients
through the wall of the digestive tract into the
bodies fluids
– Small bowel and nutrient absorption
Slide
Mosby items and derived items © 2007, 2003 by Mosby, Inc.
9
Characteristics of Life
• Secretion – production and delivery of
specialized substances
– Digestive juices or hormones
• Excretion – removal of waste products
produced during the bodies functions
– CO2 exhaled
Slide
Mosby items and derived items © 2007, 2003 by Mosby, Inc.
10
Characteristics of Life
• Circulation – movement of body fluids and
many other substances from one place in the
body to another
– O2 to the bodies cells
• Reproduction – formation of new cells or a new
individual
– Mitosis
Slide
Mosby items and derived items © 2007, 2003 by Mosby, Inc.
11
Characteristics of Life
• Metabolism – the sum total of all physical and
chemical reactions occurring in the living body
Slide
Mosby items and derived items © 2007, 2003 by Mosby, Inc.
12
Slide
Mosby items and derived items © 2007, 2003 by Mosby, Inc.
13
Levels of Organization (Figure 13)
• Chemical level—basis for life
– Organization of chemical structures separates living
material from nonliving material
– Combinations of atoms form molecules
– Combinations of molecules and atoms form
macromolecules results in living matter
– The complex relationship between these form a gel
called cytoplasm
• The essential material to human life
Slide
Mosby items and derived items © 2007, 2003 by Mosby, Inc.
14
Levels of Organization
• Organelle level
– Chemical structures organize to form organelles that perform
individual functions
– The functions of the organelles that allow the cell to live
– Dozens of organelles have been identified, including the
following:
• Mitochondria
• Golgi apparatus
• Endoplasmic reticulum
Slide
Mosby items and derived items © 2007, 2003 by Mosby, Inc.
15
Levels of Organization
• Cellular level
– Cells are the smallest and most numerous units that
possess and exhibit characteristics of life
– A cells nucleus is surrounded by cytoplasm within a
limiting membrane
– Cells differentiate to perform unique functions
Slide
Mosby items and derived items © 2007, 2003 by Mosby, Inc.
16
Levels of Organization
• Tissue level
– Tissue consist of an organization of similar cells specialized
to perform a certain function
– Tissue cells are surrounded by nonliving matrix and are the
fabric of the body
– Four major tissue types:
•
•
•
•
Epithelial tissue
Connective tissue
Muscle tissue
Nervous tissue
Slide
Mosby items and derived items © 2007, 2003 by Mosby, Inc.
17
Levels of Organization
• Organ level
– An organ is several different kinds of tissues that
combine to perform a special function
– Organs represent discrete and functionally complex
operational units
– Each organ has a unique size, shape, appearance, and
placement in the body
Slide
Mosby items and derived items © 2007, 2003 by Mosby, Inc.
18
Levels of Organization
• System level
– System – the most complex organizational unit of the body
– The system level involves varying numbers and kinds of
organs arranged to perform complex functions (Table 1-1):
• Outer protection
• Support and movement
• Communication, control, and integration
• Transportation and defense
• Respiration, nutrition, and excretion
• Reproduction and development
Slide
Mosby items and derived items © 2007, 2003 by Mosby, Inc.
19
Levels of Organization
• Organism level
– The living human organism is greater than the sum
of its parts
– All of the components (chemical – system) work
together to allow the human to survive and flourish
Slide
Mosby items and derived items © 2007, 2003 by Mosby, Inc.
20
Anatomical Position (Figure 1-4)
• Reference position for A&P and Positioning
• Body erect or standing, with arms at sides, palms
turned forward, and the head and feet pointing
forward
Slide
Mosby items and derived items © 2007, 2003 by Mosby, Inc.
21
Anatomical
Position
Slide
Mosby items and derived items © 2007, 2003 by Mosby, Inc.
22
Anatomical Position (Figure 1-4)
• Bilateral symmetry is a term meaning that right and left
sides of body are mirror images
– Bilateral symmetry confers balanced proportions
– There is remarkable correspondence of size and shape
between body parts on opposite sides of the body
– Ipsilateral structures are on the same side of the body in
anatomical position
– Contralateral structures are on opposite sides of the body in
anatomical position
Slide
Mosby items and derived items © 2007, 2003 by Mosby, Inc.
23
Body Cavities (Figure 1-5; Table
1-2)
• Ventral body cavity
– Thoracic cavity
• Right and left pleural cavities
• Mediastinum
– Abdominopelvic cavity
• Abdominal cavity
• Pelvic cavity
Slide
Mosby items and derived items © 2007, 2003 by Mosby, Inc.
24
Slide
Mosby items and derived items © 2007, 2003 by Mosby, Inc.
25
Body Cavities
• Dorsal body cavity
– Cranial cavity
– Spinal cavity
Slide
Mosby items and derived items © 2007, 2003 by Mosby, Inc.
26
Slide
Mosby items and derived items © 2007, 2003 by Mosby, Inc.
27
Body Regions
• Abdominopelvic quadrants (Figure 1-8)
–
–
–
–
Right upper quadrant
Left upper quadrant
Right lower quadrant
Left lower quadrant
Slide
Mosby items and derived items © 2007, 2003 by Mosby, Inc.
28
Slide
Mosby items and derived items © 2007, 2003 by Mosby, Inc.
29
Body Regions
• Abdominal regions (Figure 1-7)
– Right hypochondriac region
– Epigastric region
– Left hypochondriac region
– Right lumbar region
– Umbilical region
– Left lumbar region
– Right iliac (inguinal) region
– Hypogastric region
– Left iliac (inguinal) regionSlide
Mosby items and derived items © 2007, 2003 by Mosby, Inc.
30
Slide
Mosby items and derived items © 2007, 2003 by Mosby, Inc.
31
Terms Used in Describing Body
Structure
• Directional terms (Figure 1-9)
–
–
–
–
–
Superior
Inferior
Anterior (ventral)
Posterior (dorsal)
Medial
–
–
–
–
–
Lateral
Proximal
Distal
Superficial
Deep
Slide
Mosby items and derived items © 2007, 2003 by Mosby, Inc.
32
•
•
•
•
•
•
Terms Used in Describing Body
Structure
Superior – towards the head
Inferior – towards the feet
Anterior – front
Posterior – back
Medial – toward the midline
Lateral – away from the midline
Slide
Mosby items and derived items © 2007, 2003 by Mosby, Inc.
33
Terms Used in Describing Body
Structure
• Proximal – toward the nearest point of
attachment or the trunk of the body
• Distal – away or furthest from the point of
attachment or trunk
• Superficial – nearer the surface
• Deep – farther from the surface
Slide
Mosby items and derived items © 2007, 2003 by Mosby, Inc.
34
Terms Used in Describing Body
Structure
• Terms related to organs
– Lumen (luminal)
– Central
– Peripheral
– Medullary (medulla)
– Cortical (cortex)
– Apical (apex)
– Basal (base)
• Many directional terms are listed inside the front
cover of the book
Slide
Mosby items and derived items © 2007, 2003 by Mosby, Inc.
35
Body Planes and Sections
(Figures 1-9 and 1-10)
• Planes are lines of orientation along which cuts
or sections can be made to divide the body, or a
body part, into smaller pieces
Slide
Mosby items and derived items © 2007, 2003 by Mosby, Inc.
36
Body Planes and Sections
(Figures 1-9 and 1-10)
• There are three major planes, which lie at right angles to
each other:
– Sagittal plane runs front to back so that sections through this
plane divide body (or body part) into right and left sides
• If section divides body (or part) into symmetrical right and left halves,
the plane is called midsagittal or median sagittal
– Frontal (coronal) plane runs lengthwise (side to side) and
divides body (or part) into anterior and posterior portions
• If section divides the body into equal anterior or posterior portions,
the plane is called midcoronal
– Transverse (horizontal) plane is a “crosswise” plane—it
divides body (or part) into upper and lower parts
Slide
Mosby items and derived items © 2007, 2003 by Mosby, Inc.
37
Slide
Mosby items and derived items © 2007, 2003 by Mosby, Inc.
38
Slide
Mosby items and derived items © 2007, 2003 by Mosby, Inc.
39
Homeostasis (Figure 1-14)
• Term homeostasis coined by the American
physiologist Walter B. Cannon
• Homeostasis is the term used to describe the
relatively constant states maintained by the
bodies internal environment
• The body maintains homeostasis through
feedback systems
Slide
Mosby items and derived items © 2007, 2003 by Mosby, Inc.
40
Slide
Mosby items and derived items © 2007, 2003 by Mosby, Inc.
41
Homeostasis (Figure 1-14)
• Examples of homeostasis:
– Temperature regulation
– Regulation of blood carbon dioxide level
– Regulation of blood glucose level
• Body adjusts important variables from a normal
“set point” in to get the body back into an
acceptable or normal range (blood pressure)
Slide
Mosby items and derived items © 2007, 2003 by Mosby, Inc.
42
Homeostatic Control
Mechanisms
• A homeostatic control mechanism is a device for maintaining or restoring
homeostasis by self-regulation through feedback control loops
• The basic components of control mechanisms:
– Sensory mechanism (receptor) – are specific sensors that detect and react to
any changes from normal
• Nerve
– Integrating, or control, center – where information is analyzed and integrated,
and then, if needed, a specific action is initiated
• CNS or Thyroid
– Effector mechanism—effectors directly influence controlled physiological
variables
• Muscle or gland
– Feedback system - processes information about a variable constantly sends
information back from the sensor to the integrator (control)
Slide
Mosby items and derived items © 2007, 2003 by Mosby, Inc.
43
Feedback
System
Example
Slide
Mosby items and derived items © 2007, 2003 by Mosby, Inc.
44
Slide
Mosby items and derived items © 2007, 2003 by Mosby, Inc.
45
Homeostatic Control
Mechanisms
• Negative feedback control system – reverses a change
in a controlled condition
– Are inhibitory
– Stabilize physiological variables
– Produce an action that is opposite to the change that
activated the system
– Are responsible for maintaining homeostasis
– Are much more common than positive feedback control
systems
– Example: Body Temperature Control or Blood Pressure
Slide
Mosby items and derived items © 2007, 2003 by Mosby, Inc.
46
Homeostatic Control
Mechanisms
• Positive feedback control system – the effector
produces a physiological responses that reinforces the
initial change in the controlled condition
– Are stimulatory
– Amplify or reinforce the change that is occurring
– Tend to produce destabilizing effects and disrupt
homeostasis
– Bring specific body functions to swift completion
– Example: Childbirth, Clotting, Immune Response, or Sneeze
Slide
Mosby items and derived items © 2007, 2003 by Mosby, Inc.
47
Slide
Mosby items and derived items © 2007, 2003 by Mosby, Inc.
48
Homeostatic Control
Mechanisms
• Levels of control (Figure 1-15)
– Intracellular control
• Regulation within cells
• Genes or enzymes can regulate cell processes
– Intrinsic control (autoregulation)
• Regulation within tissues or organs
• May involve chemical signals
• May involve other “built-in” mechanisms
– Extrinsic control
• Regulation from organ to organ
• May involve nerve signals
• May involve endocrine signals (hormones)
Slide
Mosby items and derived items © 2007, 2003 by Mosby, Inc.
49
Slide
Mosby items and derived items © 2007, 2003 by Mosby, Inc.
50
Cycle of Life:
Life Span Considerations
• Structure and function of body undergo
changes over the early years (developmental
processes) and late years (aging processes)
• Infancy and old age are periods of time when
the body functions least well
Slide
Mosby items and derived items © 2007, 2003 by Mosby, Inc.
51
Cycle of Life:
Life Span Considerations
• Young adulthood is period of greatest
homeostatic efficiency
• Atrophy—term to describe the wasting effects
of advancing age
Slide
Mosby items and derived items © 2007, 2003 by Mosby, Inc.
52
Questions?
Slide
Mosby items and derived items © 2007, 2003 by Mosby, Inc.
53