WELCOME TO A&P I
Suffolk County Community College
Sayville Campus
Adriana Pinkas, PhD
pinkasa@sunysuffolk.edu
http://www2.sunysuffolk.edu/pinkasa
Why do we want to know how our body works?
• Anatomy and physiology (A&P) is about the biology of the
human body
• A&P approaches are complementary and never entirely separable
• Anatomy is the study of human body structures and their relation to each other
(Form)
• Physiology is the study of human body function
• General principle in biology - Form Follows Function - for a certain function to
be done, a biological structure will adapt a certain form.
• A&P is a foundation for advanced study in health care, exercise
physiology, pathophysiology, and other health-care-related fields
• Considers the historical development and a central concept of
physiology - homeostasis
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Anatomy - The Study of Form
• Examining structure of the human body
• Inspection - looking at the body appearance
• Palpation - feeling a structure with the hands
• Auscultation - listening to the natural
sounds made by the body
• Percussion – tap the body, feel resistance
Figure 1.1
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Anatomy - The Study of Form
• Cadaver dissection
• Cutting and separation of tissues to reveal their relationships
• Comparative anatomy
• Study of more than one species in order to examine structural similarities
and differences, and analyze evolutionary trends
Anatomy - The Study of Form
• Gross anatomy - Study of structures that can be seen with the naked eye
• Exploratory surgery
• Open body and take a look inside
• Medical imaging
• Viewing the inside of the body without surgery
• Radiology—branch of medicine concerned with imaging
• Microscopic anatomy
• Histology - Examination of cells with microscope
• Histopathology
• Microscopic examination of tissues for signs of disease
• Cytology
• Study of structure and function of cells
• Ultrastructure
• View molecular detail under electron microscope
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Physiology - The Study of Function
• Subdisciplines
• Neurophysiology (physiology of nervous system)
• Endocrinology (physiology of hormones)
• Pathophysiology (mechanisms of disease)
• Comparative physiology
• Limitations on human experimentation
• Study of different species to learn about bodily function
• Animal surgery
• Animal drug tests
• Basis for the development of new drugs and medical procedures
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Living in a Revolution
• Early pioneers were important
• Established scientific way of thinking
• Replaced superstition with natural laws
• Cell Theory - All living things are composed of cells and come from preexisting cells
• Modern biomedical science
• Technological enhancements
• Advances in medical imaging have enhanced our diagnostic ability and life-support
strategies
• Genetic Revolution
• Human genome is finished
• Gene therapy is being used to treat disease
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Anatomical Variation
• No two humans are exactly alike
• 70% most common structure
• 30% anatomically variant
• Variable number of organs
• Missing muscles, extra vertebrae, renal arteries
• Variation in organ locations
• situs solitus - normal
• situs inversus – organs reversed right to left
• dextrocardia - right-left reversal of the heart
• situs perversus – single organ occupies
an atypical position
Normal
Pelvic kidney
Normal
Horseshoe kidney
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Variations in branches of the aorta
Physiological Variation
• Sex, age, diet, weight, physical activity
• Typical physiological values – heart rate, blood pressure, body
temperature
• reference man
• 22 years old, 154 lbs, light physical activity
• consumes 2800 kcal/day
• reference woman
• same as man except 128 lbs and 2000 kcal/day
• Failure to consider variation can lead to overmedication of elderly or
medicating women on the basis of research done on men
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Common characteristics of life
• Organization
• living things vs nonliving world -pattern that differs from environment, involves regulation
of internal conditions within limit
• Homeostasis
• ability to maintain internal stability
• Responsiveness and movement
• ability to sense and react to stimuli; adaptation is a long term response
• Cellular composition
• all living tings are composed of cells
• Metabolism
• Anabolism, catabolism and excretion (energy )
• Development
• growth - increase in size/cell number
• differentiation - specialization of cells to perform particular functions
• Reproduction
• produce copies of themselves (passing their genes to offspring)
• Evolution
• Mutations- change in DNA (genes)
• Natural selection – favor of transmission of some genes more than others
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Human structure - hierarchy of complexity
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• Organism
• a single, complete individual
• Organ System
• human body made of 11 organ systems
• Organ
• structure composed of two or more tissue types that work
together to carry out a particular function
• Tissue –
• a mass of similar cells and cell products that form
discrete region of an organ and performs a specific
function
• Cells
• the smallest units of an organism that carry out all the
basic functions of life
• Cytology – the study of cells and organelles
• Organelles
• microscopic structures in a cell that carry out its
individual functions
• Molecules
•
make up organelles and other cellular components
• macromolecules – proteins, carbohydrates, fats, DNA
• Atoms –
• the smallest particles with unique chemical identities
The pattern of organization at the lower levels determines
both the characteristics and functions at the higher levels
Homeostasis
• Homeostasis – the body’s ability to detect change, activate
mechanisms that oppose it, and thereby maintain relatively stable
internal conditions
• keeping within set limits
• The internal environment of the body is in a dynamic state of
equilibrium
• Auto regulation (intrinsic) - when a cell, organ, or organ system automatically
adjusts itself in response to a change in the environment
• Extrinsic regulation – results from activity of nervous system and hormones
(chemical messages) of endocrine system
• Loss of homeostatic control causes illness or death
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Negative Feedback Loop
Body senses a change and activates mechanisms to reverse it - dynamic
equilibrium
Because feedback mechanisms alter the original changes that triggered them
(temperature, for example), they are called feedback loops
Negative Feedback
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Core body temperature
Sweating
37.5 oC
(99.5
oF)
Vasodilation
37.0 oC
(98.6
oF)
36.5 oC
(97.7
oF)
Set point
Vasoconstriction
Figure 1.10
Time
Shivering
• Example: Brain senses change in blood temperature
• If too warm, vessels dilate (vasodilation) in the skin and sweating begins
(heat-losing mechanism)
• If too cold, vessels in the skin constrict (vasoconstriction)
and shivering begins (heat-gaining mechanism)
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Homeostasis and Negative Feedback
Postural Change in Blood Pressure
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Person rises
from bed
Blood pressure rises
to normal; homeostasis
is restored
Cardiac center
accelerates heartbeat
Blood drains from
upper body, creating
homeostatic imbalance
Baroreceptors above
heart respond to drop
in blood pressure
Figure 1.11
Baroreceptors send signals
to cardiac center of brainstem
Homeostatic Control Mechanisms
• Receptor - senses change in the body (e.g., stretch receptors
that monitor blood pressure)
• Integrating (control) center - control center that processes the
sensory information, “makes a decision,” and directs the
response (e.g., cardiac center of the brain)
• Effector - carries out the final corrective action to restore
homeostasis (e.g., cell or organ)
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Positive Feedback and Rapid Change
• Self-amplifying cycle
• Leads to greater change in the same direction
• Feedback loop is repeated - change produces more change
• Normal way of producing rapid changes
• Occurs with childbirth, blood clotting, protein digestion, fever, and
generation of nerve signals
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Positive Feedback Loops
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
3 Brain stimulates
pituitary gland to
secrete oxytocin
4
Oxytocin stimulates uterine
contractions and pushes
fetus toward cervix
2 Nerve impulses
from cervix
transmitted
to brain
1 Head of fetus
pushes against cervix
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Positive Feedback and Rapid Change
• A Fever triggered by infection is beneficial
•
•
•
•
Metabolic rate increases
Body produces heat even faster
Body temperature continues to rise
Further increasing metabolic rate
• Cycle continues to reinforce itself > 40°C (104°F)
• It may create dangerous positive feedback loop
• Becomes fatal at 45°C (113°F)
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Review of Major Themes
• Unity of Form and Function
• Form and function complement each other; physiology cannot be divorced
from anatomy
• Cell Theory
• All structure and function result from the activity of cells
• Homeostasis
• The purpose of most normal physiology is to maintain stable conditions within
the body
• Evolution
• The human body is a product of evolution
• Hierarchy of Structure
• Human structure can be viewed as a series of levels of complexity
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Medical Imaging
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
•Radiography (Xrays)
• William Roentgen’s discovery in
1885
• Penetrate tissues to darken
photographic film beneath the body
• Dense tissue appears white
• Over half of all medical imaging
• Until 1960s, it was the only method
widely available
(a) X-ray (radiograph)
© U.H.B. Trust/Tony Stone Images/Getty Imagese
Figure 1.13a
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Medical Imaging
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
• Radiopaque substances
• Injected or swallowed
• Fills hollow structures
• Blood vessels
• Intestinal tract
Figure 1.13b
(b Cerebral angiogram
Custom Medical Stock Photos, Inc.
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Medical Imaging
• Computed tomography
(CT scan)
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
• Formerly called a CAT scan
• Low-intensity X-rays and
computer analysis
• Slice-type image
• Increased sharpness of image
Figure 1.13c
(c) Computed tomographic (CT) scan
© CNR/Phototake
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Medical Imaging—Nuclear Medicine
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
• Positron emission tomography (PET)
scan
• Assesses metabolic state of tissue
• Distinguished tissues most active at a
given moment
• Mechanics—inject radioactively labeled
glucose
•
•
•
•
•
(d) Positron emission tomographic
(PET) scan
Positrons and electrons collide
Gamma rays given off
Detected by sensor
Analyzed by computer
Image color shows tissues using the most
glucose at that moment
• Damaged tissues appear dark
Tony Stone Images/Getty Images
Figure 1.13d
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Medical Imaging
• Magnetic resonance imaging
(MRI)
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
• Slice-type image
• Superior quality to CT scan
• Best for soft tissue
• Mechanics
• Alignment and realignment of
hydrogen atoms with magnetic
field and radio waves
• Varying levels of energy given
off used by computer to produce
an image
(e) Magnetic resonance image (MRI)
© Monte S. Buchsbaum, Mt. Sinai School of Medicine, New York, NY
Figure 1.13e
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Medical Imaging
• Sonography
• Second oldest and second
most widely used
• Mechanics
• High-frequency sound waves
echo back
from internal organs
• Avoids harmful X-rays
• Obstetrics
• Image not very sharp
Figure 1.14
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Expected Learning Outcomes
• The Scope of Anatomy and Physiology
• Define anatomy and physiology and relate them to each other.
• Describe several ways of studying human anatomy.
• Define a few subdisciplines of human physiology.
• Human Structure
• List the levels of human structure from the most complex to the simplest.
• Discuss the clinical significance of anatomical variation among humans.
• Human Function
• State the characteristics that distinguish living organisms from nonliving
objects.
• Explain the importance of defining a reference man and woman.
• Define homeostasis and explain why this concept is central to physiology.
• Define negative feedback, give an example of it, and explain its
importance to homeostasis.
• Define positive feedback and give examples of its beneficial and harmful
effects.
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