cva a&p - chapter 1a intro and homeostasis

PowerPoint® Lecture Slide Presentation by Patty Bostwick-Taylor, Florence-Darlington Technical College

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings

PART A1

The Human Body: An Orientation


The Human Body—An OrientationAnatomy

Study of the structure and shape of the body and its parts

Physiology Study of how the body and its parts work or

function


Anatomy—Levels of Study Gross anatomy

Large structures Easily observable

Figure 14.1


Anatomy—Levels of Study Microscopic Anatomy

Very small structures

Can only be viewed with a microscope

Figure 14.4c–d


Levels of Structural Organization

Figure 1.1, step 1

Molecules

Atoms

Chemical levelAtoms combine toform molecules



Figure 1.1, step 2

Smooth muscle cellMolecules

AtomsCellular levelCells are made up of molecules




Figure 1.1, step 3


Atoms

Smoothmuscletissue

Cellular levelCells are made up of molecules

Tissue levelTissues consist ofsimilar types of cells




Figure 1.1, step 4


Atoms

Smoothmuscletissue

Epithelialtissue

Smoothmuscletissue

Connectivetissue

Bloodvessel(organ)



Organ levelOrgans are made upof different typesof tissues




Figure 1.1, step 5


Atoms

Smoothmuscletissue

Epithelialtissue

Smoothmuscletissue

Connectivetissue

Bloodvessel(organ) Cardio-

vascularsystem




Organ system levelOrgan systems consist of differentorgans that work together closely




Figure 1.1, step 6


Atoms

Smoothmuscletissue

Epithelialtissue

Smoothmuscletissue

Connectivetissue

Bloodvessel(organ) Cardio-

vascularsystem




Organ system levelOrgan systems consist of differentorgans that work together closely

Organismal levelHuman organismsare made up of manyorgan systems



Necessary Life Functions Maintain boundaries Movement

Locomotion Movement of substances

Responsiveness Ability to sense changes and react

Digestion Break-down and absorption of nutrients


Necessary Life Functions Metabolism—chemical reactions within the body

Produces energy Makes body structures

Excretion Eliminates waste from metabolic reactions


Necessary Life Functions Reproduction

Produces future generation Growth

Increases cell size and number of cells


Survival Needs Nutrients

Chemicals for energy and cell building Includes carbohydrates, proteins, lipids,

vitamins, and minerals Oxygen

Required for chemical reactions


Survival Needs Water

60–80% of body weight Provides for metabolic reaction

Stable body temperature Atmospheric pressure

Must be appropriate


Homeostasis Homeostasis—maintenance of a stable internal

environment A dynamic state of equilibrium

Homeostasis is necessary for normal body functioning and to sustain life

Homeostatic imbalance A disturbance in homeostasis resulting in

disease


Maintaining Homeostasis The body communicates through neural and

hormonal control systems Receptor

Responds to changes in the environment (stimuli)

Sends information to control center


Maintaining Homeostasis Control center

Determines set point Analyzes information Determines appropriate response

Effector Provides a means for response to the

stimulus


Figure 1.4, step 1a

Variable(in homeostasis)


Figure 1.4, step 1b

Stimulus:Produceschangein variable


Imbalance

Imbalance


Figure 1.4, step 2

Changedetectedby receptor


Receptor (sensor)


Imbalance

Imbalance


Figure 1.4, step 3



Input:Informationsent alongafferentpathway to

Receptor (sensor)


Controlcenter

Imbalance

Imbalance


Figure 1.4, step 4




Receptor (sensor) Effector


Output:Information sentalong efferentpathway to activate

Controlcenter

Imbalance

Imbalance


Figure 1.4, step 5




Receptor (sensor) Effector


Response ofeffector feedsback toinfluencemagnitude ofstimulus andreturns variableto homeostasis

Output:Information sentalong efferentpathway to activate

Controlcenter

Imbalance

Imbalance


Feedback Mechanisms Negative feedback

Includes most homeostatic control mechanisms

Shuts off the original stimulus, or reduces its intensity

Works like a household thermostat


Feedback Mechanisms Positive feedback

Increases the original stimulus to push the variable farther

In the body this only occurs in blood clotting and during the birth of a baby

cva a&p - chapter 1a intro and homeostasis

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