WELCOME TO A&P I Suffolk County Community College Sayville Campus Adriana Pinkas, PhD [email protected]

WELCOME TO A&P I

Suffolk County Community CollegeSayville Campus

Adriana Pinkas, PhD

[email protected]

http://www2.sunysuffolk.edu/pinkasa

mailto:[email protected]

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

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Figure 1.1


• 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


• 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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Horseshoe kidney

Normal

Normal

Variations in branches of the aorta

Pelvic kidney

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 occupiesan atypical position

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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• 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

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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 LoopBody senses a change and activates mechanisms to reverse it - dynamic equilibriumBecause feedback mechanisms alter the original changes that triggered them (temperature, for example), they are called feedback loops

Negative Feedback

• 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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Figure 1.10

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

Vasoconstriction

Vasodilation

Set point

Time

Shivering

37.5 oC(99.5 oF)

37.0 oC(98.6 oF)

36.5 oC(97.7 oF)

Cor

e b

ody

te

mp

era

ture

Sweating

Homeostasis and Negative FeedbackPostural Change in Blood Pressure

Figure 1.11

Baroreceptors send signalsto cardiac center of brainstem

Baroreceptors aboveheart respond to dropin blood pressure

Cardiac centeraccelerates heartbeat

Blood pressure risesto normal; homeostasisis restored

Blood drains fromupper body, creatinghomeostatic imbalance

Person risesfrom bed


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 LoopsCopyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

3

4

1

Oxytocin stimulates uterinecontractions and pushesfetus toward cervix

Nerve impulsesfrom cervixtransmittedto brain

Brain stimulatespituitary gland tosecrete oxytocin

Head of fetuspushes against cervix

2

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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

•Radiography (X-rays)

• 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

1-21Figure 1.13a

© U.H.B. Trust/Tony Stone Images/Getty Imagese

(a) X-ray (radiograph)


Medical Imaging

• Radiopaque substances• Injected or swallowed • Fills hollow structures

• Blood vessels• Intestinal tract

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Figure 1.13b

(b Cerebral angiogram


Custom Medical Stock Photos, Inc.

Medical Imaging

• Computed tomography (CT scan)

• Formerly called a CAT scan• Low-intensity X-rays and

computer analysis• Slice-type image• Increased sharpness of image

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Figure 1.13c (c) Computed tomographic (CT) scan


© CNR/Phototake

Medical Imaging—Nuclear Medicine

• Positron emission tomography (PET) scan

• Assesses metabolic state of tissue• Distinguished tissues most active at a

given moment• Mechanics—inject radioactively labeled

glucose• 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

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Figure 1.13d

(d) Positron emission tomographic(PET) scan


Tony Stone Images/Getty Images

Medical Imaging

• Magnetic resonance imaging (MRI)

• 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

1-25Figure 1.13e

(e) Magnetic resonance image (MRI)


© Monte S. Buchsbaum, Mt. Sinai School of Medicine, New York, NY

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

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Figure 1.14

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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Documents

WELCOME TO A&P I Suffolk County Community College Sayville Campus Adriana Pinkas, PhD [email protected]