Transcript 1 - Oakton Community College

CHAPTER # 1(a)
THE HUMAN BODY:
AN ORIENTATION
Copyright © 2010 Pearson Education, Inc.
Overview of Anatomy and Physiology
• Anatomy: The study of structure
• Subdivisions:
• Gross or macroscopic (e.g., regional, surface,
and systemic anatomy)
• Microscopic (e.g., cytology and histology)
• Developmental (e.g., embryology)
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Overview of Anatomy and Physiology
• Essential tools for the study of anatomy:
• Mastery of anatomical terminology
• Observation
• Manipulation
• Palpation
• Auscultation
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Overview of Anatomy and Physiology
• Physiology: The study of function at many
levels
• Subdivisions are based on organ systems
(e.g., renal or cardiovascular physiology)
Copyright © 2010 Pearson Education, Inc.
Overview of Anatomy and Physiology
• Essential tools for the study of physiology:
• Ability to focus at many levels (from systemic
to cellular and molecular)
• Basic physical principles (e.g., electrical
currents, pressure, and movement)
• Basic chemical principles
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Principle of Complementarity
• Anatomy and physiology are inseparable.
• Function always reflects structure
• What a structure can do depends on its
specific form
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Levels of Structural Organization
• Chemical: atoms and molecules (Chapter 2)
• Cellular: cells and their organelles (Chapter 3)
• Tissue: groups of similar cells (Chapter 4)
• Organ: contains two or more types of tissues
• Organ system: organs that work closely
together
• Organismal: all organ systems
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Atoms
Organelle
Smooth muscle cell
Molecule
1 Chemical level
Atoms combine to form molecules.
Cardiovascular
system
Heart
Blood
vessels
2 Cellular level
Cells are made up of
molecules.
Smooth muscle tissue
3 Tissue level
Tissues consist of similar
types of cells.
Blood vessel (organ)
Smooth muscle tissue
Connective tissue
Epithelial
tissue
4 Organ level
Organs are made up of different types
of tissues.
6 Organismal level
The human organism is made up
of many organ systems.
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5 Organ system level
Organ systems consist of different
organs that work together closely.
Figure 1.1
Atoms
Molecule
1 Chemical level
Atoms combine to form molecules.
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Figure 1.1, step 1
Atoms
Molecule
1 Chemical level
Atoms combine to form molecules.
Copyright © 2010 Pearson Education, Inc.
Organelle
Smooth muscle cell
2 Cellular level
Cells are made up of
molecules.
Figure 1.1, step 2
Atoms
Molecule
1 Chemical level
Atoms combine to form molecules.
Organelle
Smooth muscle cell
2 Cellular level
Cells are made up of
molecules.
Smooth muscle tissue
3 Tissue level
Tissues consist of similar
types of cells.
Copyright © 2010 Pearson Education, Inc.
Figure 1.1, step 3
Atoms
Molecule
1 Chemical level
Atoms combine to form molecules.
Organelle
Smooth muscle cell
2 Cellular level
Cells are made up of
molecules.
Smooth muscle tissue
3 Tissue level
Tissues consist of similar
types of cells.
Blood vessel (organ)
Smooth muscle tissue
Connective tissue
Epithelial
tissue
4 Organ level
Organs are made up of different types
of tissues.
Copyright © 2010 Pearson Education, Inc.
Figure 1.1, step 4
Atoms
Organelle
Smooth muscle cell
Molecule
1 Chemical level
Atoms combine to form molecules.
Cardiovascular
system
Heart
Blood
vessels
2 Cellular level
Cells are made up of
molecules.
Smooth muscle tissue
3 Tissue level
Tissues consist of similar
types of cells.
Blood vessel (organ)
Smooth muscle tissue
Connective tissue
Epithelial
tissue
4 Organ level
Organs are made up of different types
of tissues.
5 Organ system level
Organ systems consist of different
organs that work together closely.
Copyright © 2010 Pearson Education, Inc.
Figure 1.1, step 5
Atoms
Organelle
Smooth muscle cell
Molecule
1 Chemical level
Atoms combine to form molecules.
Cardiovascular
system
Heart
Blood
vessels
2 Cellular level
Cells are made up of
molecules.
Smooth muscle tissue
3 Tissue level
Tissues consist of similar
types of cells.
Blood vessel (organ)
Smooth muscle tissue
Connective tissue
Epithelial
tissue
4 Organ level
Organs are made up of different types
of tissues.
6 Organismal level
The human organism is made up
of many organ systems.
Copyright © 2010 Pearson Education, Inc.
5 Organ system level
Organ systems consist of different
organs that work together closely.
Figure 1.1, step 6
Overview of Organ Systems
• Note major organs and functions of the 11
organ systems (Fig. 1.3)
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Hair
Skin
Nails
(a) Integumentary System
Forms the external body covering, and
protects deeper tissues from injury.
Synthesizes vitamin D, and houses
cutaneous (pain, pressure, etc.)
receptors and sweat and oil glands.
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Figure 1.3a
Bones
Joint
(b) Skeletal System
Protects and supports body organs,
and provides a framework the muscles
use to cause movement. Blood cells
are formed within bones. Bones store
minerals.
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Figure 1.3b
Skeletal
muscles
(c) Muscular System
Allows manipulation of the environment,
locomotion, and facial expression. Maintains posture, and produces heat.
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Figure 1.3c
Brain
Spinal
cord
Nerves
(d) Nervous System
As the fast-acting control system of
the body, it responds to internal and
external changes by activating
appropriate muscles and glands.
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Figure 1.3d
Pineal gland
Pituitary
gland
Thyroid
gland
Thymus
Adrenal
gland
Pancreas
Testis
Ovary
(e) Endocrine System
Glands secrete hormones that regulate
processes such as growth, reproduction,
and nutrient use (metabolism) by body
cells.
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Figure 1.3e
Heart
Blood
vessels
(f) Cardiovascular System
Blood vessels transport blood,
which carries oxygen, carbon
dioxide, nutrients, wastes, etc.
The heart pumps blood.
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Figure 1.3f
Red bone
marrow
Thymus
Lymphatic
vessels
Thoracic
duct
Spleen
Lymph
nodes
(g) Lymphatic System/Immunity
Picks up fluid leaked from blood vessels
and returns it to blood. Disposes of debris
in the lymphatic stream. Houses white
blood cells (lymphocytes) involved in
immunity. The immune response mounts
the attack against foreign substances
within the body.
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Figure 1.3g
Nasal
cavity
Pharynx
Larynx
Trachea
Bronchus
Lung
(h) Respiratory System
Keeps blood constantly supplied with
oxygen and removes carbon dioxide.
The gaseous exchanges occur through
the walls of the air sacs of the lungs.
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Figure 1.3h
Oral cavity
Esophagus
Liver
Stomach
Small
intestine
Large
intestine
Rectum
Anus
(i) Digestive System
Breaks down food into absorbable
units that enter the blood for
distribution to body cells. Indigestible
foodstuffs are eliminated as feces.
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Figure 1.3i
Kidney
Ureter
Urinary
bladder
Urethra
(j) Urinary System
Eliminates nitrogenous wastes from the
body. Regulates water, electrolyte and
acid-base balance of the blood.
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Figure 1.3j
Mammary
glands (in
breasts)
Prostate
gland
Ovary
Penis
Testis
Scrotum
Ductus
deferens
Uterus
Vagina
Uterine
tube
(l) Female Reproductive System
(k) Male Reproductive System
Overall function is production of offspring. Testes produce sperm and male sex
hormone, and male ducts and glands aid in delivery of sperm to the female
reproductive tract. Ovaries produce eggs and female sex hormones. The remaining
female structures serve as sites for fertilization and development of the fetus.
Mammary glands of female breasts produce milk to nourish the newborn.
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Figure 1.3k-l
Organ Systems Interrelationships
• All cells depend on organ systems to meet
their survival needs
• Organ systems work cooperatively to perform
necessary life functions
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Digestive system
Takes in nutrients, breaks them
down, and eliminates unabsorbed
matter (feces)
Respiratory system
Takes in oxygen and
eliminates carbon dioxide
Food
O2
CO2
Cardiovascular system
Via the blood, distributes oxygen
and nutrients to all body cells and
delivers wastes and carbon
dioxide to disposal organs
Blood
CO2
O2
Heart
Nutrients
Interstitial fluid
Urinary
system
Eliminates
nitrogenous
wastes and
excess ions
Nutrients and wastes pass
between blood and cells
via the interstitial fluid
Integumentary system
Feces Protects the body as a whole Urine
from the external environment
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Figure 1.2
Necessary Life Functions
1. Maintaining boundaries between internal
and external environments
•
Plasma membranes
•
Skin
2. Movement (contractility)
•
Of body parts (skeletal muscle)
•
Of substances (cardiac and smooth muscle)
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Necessary Life Functions
3. Responsiveness: The ability to sense and
respond to stimuli
•
Withdrawal reflex
•
Control of breathing rate
4. Digestion
•
Breakdown of ingested foodstuffs
•
Absorption of simple molecules into blood
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Necessary Life Functions
5. Metabolism: All chemical reactions that
occur in body cells
•
Catabolism and anabolism
6. Excretion: The removal of wastes from
metabolism and digestion
•
Urea, carbon dioxide, feces
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Necessary Life Functions
7. Reproduction
•
Cellular division for growth or repair
•
Production of offspring
8. Growth: Increase in size of a body part or of
organism
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Survival Needs
1. Nutrients
•
Chemicals for energy and cell building
•
Carbohydrates, fats, proteins, minerals,
vitamins
2. Oxygen
•
Essential for energy release (ATP
production)
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Survival Needs
3. Water
•
Most abundant chemical in the body
•
Site of chemical reactions
4. Normal body temperature
•
Affects rate of chemical reactions
5. Appropriate atmospheric pressure
•
For adequate breathing and gas exchange in
the lungs
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Homeostasis
• Maintenance of a relatively stable internal
environment despite continuous outside
changes
• A dynamic state of equilibrium
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Homeostatic Control Mechanisms
• Involve continuous monitoring and regulation
of many factors (variables)
• Nervous and endocrine systems accomplish
the communication via nerve impulses and
hormones
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Components of a Control Mechanism
1. Receptor (sensor)
•
Monitors the environment
•
Responds to stimuli (changes in controlled variables)
2. Control center
•
Determines the set point at which the variable is
maintained
•
Receives input from receptor
•
Determines appropriate response
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Components of a Control Mechanism
3. Effector
•
Receives output from control center
•
Provides the means to respond
•
Response acts to reduce or enhance the
stimulus (feedback)
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3 Input: Information
sent along afferent
pathway to control
center.
2
Receptor
detects
change.
Receptor
4 Output:
Control
Center
Afferent
Efferent
pathway
pathway
1
Stimulus
produces
change in
variable.
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BALANCE
Information sent along
efferent pathway to
effector.
Effector
5
Response
of effector
feeds back
to reduce
the effect of
stimulus
and returns
variable to
homeostatic
level.
Figure 1.4
1
Stimulus
produces
change in
variable.
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BALANCE
Figure 1.4, step 1
2
Receptor
detects
change.
Receptor
1
Stimulus
produces
change in
variable.
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BALANCE
Figure 1.4, step 2
3 Input: Information
sent along afferent
pathway to control
center.
2
Receptor
detects
change.
Receptor
Control
Center
Afferent
pathway
1
Stimulus
produces
change in
variable.
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BALANCE
Figure 1.4, step 3
3 Input: Information
sent along afferent
pathway to control
center.
2
Receptor
detects
change.
Receptor
4 Output:
Control
Center
Afferent
Efferent
pathway
pathway
Information sent along
efferent pathway to
effector.
Effector
1
Stimulus
produces
change in
variable.
Copyright © 2010 Pearson Education, Inc.
BALANCE
Figure 1.4, step 4
3 Input: Information
sent along afferent
pathway to control
center.
2
Receptor
detects
change.
Receptor
4 Output:
Control
Center
Afferent
Efferent
pathway
pathway
1
Stimulus
produces
change in
variable.
Copyright © 2010 Pearson Education, Inc.
BALANCE
Information sent along
efferent pathway to
effector.
Effector
5
Response
of effector
feeds back
to reduce
the effect of
stimulus
and returns
variable to
homeostatic
level.
Figure 1.4, step 5
Negative Feedback
• The response reduces or shuts off the original
stimulus
• Examples:
• Regulation of body temperature (a nervous
mechanism)
• Regulation of blood volume by ADH (an
endocrine mechanism)
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Control Center
(thermoregulatory
center in brain)
Information sent
along the afferent
pathway to control
center
Afferent
pathway
Information sent
along the efferent
pathway to
effectors
Efferent
pathway
Receptors
Temperature-sensitive
cells in skin and brain
Effectors
Sweat glands
Sweat glands activated
Response
Evaporation of sweat
Body temperature falls;
stimulus ends
Stimulus
Body temperature
rises
BALANCE
Stimulus
Response
Body temperature rises;
stimulus ends
Body temperature falls
Receptors
Temperature-sensitive
cells in skin and brain
Effectors
Skeletal muscles
Shivering
begins
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Efferent
pathway
Information sent
along the efferent
pathway to effectors
Afferent
pathway
Control Center
(thermoregulatory
center in brain)
Information sent
along the afferent
pathway to control
center
Figure 1.5
Negative Feedback: Regulation of Blood
Volume by ADH
• Receptors sense decreased blood volume
• Control center in hypothalamus stimulates
pituitary gland to release antidiuretic hormone
(ADH)
• ADH causes the kidneys (effectors) to return
more water to the blood
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Positive Feedback
• The response enhances or exaggerates the
original stimulus
• May exhibit a cascade or amplifying effect
• Usually controls infrequent events e.g.:
• Enhancement of labor contractions by oxytocin
(Chapter 28)
• Platelet plug formation and blood clotting
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1 Break or tear
occurs in blood
vessel wall.
Positive feedback
cycle is initiated.
3 Released
chemicals
attract more
platelets.
2 Platelets
Positive
feedback
loop
adhere to site
and release
chemicals.
Feedback cycle ends
when plug is formed.
4 Platelet plug
forms.
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Figure 1.6
1 Break or tear
occurs in blood
vessel wall.
Positive feedback
cycle is initiated.
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Figure 1.6, step 1
1 Break or tear
occurs in blood
vessel wall.
Positive feedback
cycle is initiated.
2 Platelets
adhere to site
and release
chemicals.
Copyright © 2010 Pearson Education, Inc.
Figure 1.6, step 2
1 Break or tear
occurs in blood
vessel wall.
Positive feedback
cycle is initiated.
3 Released
chemicals
attract more
platelets.
Copyright © 2010 Pearson Education, Inc.
2 Platelets
Positive
feedback
loop
adhere to site
and release
chemicals.
Figure 1.6, step 3
1 Break or tear
occurs in blood
vessel wall.
Positive feedback
cycle is initiated.
3 Released
chemicals
attract more
platelets.
2 Platelets
Positive
feedback
loop
adhere to site
and release
chemicals.
Feedback cycle ends
when plug is formed.
4 Platelet plug
forms.
Copyright © 2010 Pearson Education, Inc.
Figure 1.6, step 4
Homeostatic Imbalance
• Disturbance of homeostasis
• Increases risk of disease
• Contributes to changes associated with aging
• May allow destructive positive feedback
mechanisms to take over (e.g., heart failure)
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