WELCOME TO A&P I Vladimir Jurukovski PhD Associate Professor Suffolk County Community College Smithtown Science Building T-218 (631) 451-4362 [email protected]

WELCOME TO A&P I

Vladimir Jurukovski PhDAssociate Professor

Suffolk County Community CollegeSmithtown Science Building T-218

(631) 451-4362

[email protected]

http://www2.sunysuffolk.edu/jurukov

mailto:[email protected]



WHAT IF…..?

INTRODUCTION

Anatomy and physiology (A&P) is about human structure and function—the biology of the human body

We want to know how our body works! 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

1-4

THE SCOPE OF ANATOMY AND PHYSIOLOGY

Expected Learning Outcomes Define anatomy and physiology and

relate them to each other. Describe several ways of studying

human anatomy. Define a few subdisciplines of human

physiology.

1-5

ANATOMY—THE STUDY OF FORM

Examining structure of the human body Inspection Palpation Auscultation Percussion

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 1-6

Figure 1.1

Cadaver Dissection

ANATOMY—THE STUDY OF FORM

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

Gross anatomy Study of structures that can be seen with the naked eye

Cytology Study of structure and function of cells

Histology (microscopic anatomy) Examination of cells with microscope

Ultrastructure View molecular detail under electron microscope

Histopathology Microscopic examination of tissues for signs of disease

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Exploratory Surgery

Medical Imaging

Cytology

Gross Anatomy

Histology

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

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

Early pioneers were important Established scientific way of thinking Replaced superstition with natural laws

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HUMAN STRUCTURE

Expected Learning Outcomes List the levels of human structure from the most

complex to the simplest. Discuss the clinical significance of anatomical

variation among humans.

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HIERARCHY OF COMPLEXITY

Organism is composed of organ systems

Organ Systems composed of organs

Organs composed of tissues

Tissues composed of cells

Cells composed of organelles

Organelles composed of molecules

Molecules composed of atoms

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Organism

Organ system Organ Tissue

Cell

OrganelleMacromolecule

MoleculeAtom

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

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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CHARACTERISTICS OF LIFE

Organization Cellular composition Metabolism

anabolism, catabolism and excretion Responsiveness and movement

Stimuli Homeostasis Development

differentiation and growth Reproduction Evolution

mutations 1-15

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,

situs inversus, dextrocardia, situs perversus)

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PHYSIOLOGICAL VARIATION

Sex, age, diet, weight, physical activity Typical physiological values

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

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HOMEOSTASIS

Homeostasis – the body’s ability to detect change, activate mechanisms that oppose it, and thereby maintain relatively stable internal conditions

Claude Bernard (1813-78) constant internal conditions regardless of external

conditions internal body temperature ranges from 97 to 99 degrees despite

variations in external temperature Walter Cannon (1871-1945)

coined the term ‘Homeostasis’ state of the body fluctuates (dynamic equilibrium)

within limited range around a set point Negative feedback keeps variable close to the set

point Loss of homeostatic control causes illness or

death 1-18

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

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Figure 1.9a


1

2

6

5

Room temperaturefallsto66°F(19°C)

Thermost atactivatesfurnace

Thermostat shutsoff furnace

Room cools down

Room temperaturerises to 70°F (21°C)

3

4

Heat output

(a)

C10°15°20°25°

80°F50°60°70°

C10°15°20°25°

80°F50°60°70°

NEGATIVE FEEDBACK

Example: Room temperature does not stay at set point of 68°F—it only averages 68°F

1-20

Figure 1.9b


(b)

60

65

70

75

Ro

om

tem

per

atu

re (

oF

)

Time

Furnace turnedon at 66 oF

Set point 68 oF

Furnace turnedoff at 70 oF

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)1-21

Figure 1.10


Vasoconstriction

Vasodilation

Set point

Time

Shivering

37.5 oC(99.5 oF)37.0 oC(98.6 oF)

36.5 oC(97.7 oF)

Core

bod

y t

em

pera

ture

Sweating

HOMEOSTATIS AND NEGATIVE FEEDBACK

Sitting up in bed causes a drop in blood pressure in the head and upper torso region (local imbalance in homeostasis); detected by baroreceptors

Baroreceptors (sensory nerve endings) in the arteries near the heart alert the cardiac center in the brainstem. They transmit to the cardiac center

Cardiac center sends nerve signals that increase the heart rate and return the blood pressure to normal; regulates heart rate

Failure of this to feedback loop may produce dizziness in the elderly

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POSTURAL 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


HOMEOSTASIS AND NEGATIVE FEEDBACK

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

1-25


During birth, the head of the fetus pushes against the cervix and stimulates its nerve endings Hormone oxytocin is secreted from the

pituitary gland Oxytocin travels through the bloodstream

to the uterus stimulating it to contract This action pushes the fetus downward

toward cervix, thus stimulating the cervix more, causing the positive feedback loop to be repeated

1-26

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

1-27


Fever > 104°F Metabolic rate increases Body produces heat even faster Body temperature continues to rise Further increasing metabolic rate

Cycle continues to reinforce itself Becomes fatal at 113°F

1-28

REVIEW OF MAJOR THEMES 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

Unity of Form and Function Form and function complement each other; physiology

cannot be divorced from anatomy1-29

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

1-30Figure 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

1-31

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

1-32

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

1-33

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

1-34Figure 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

1-35

Figure 1.14

Documents

WELCOME TO A&P I Vladimir Jurukovski PhD Associate Professor Suffolk County Community College Smithtown Science Building T-218 (631) 451-4362 [email protected]