Download Chapter 1: Organization of the Body

Introduction:
Anatomy and Physiology
Organization of the body, Chemistry of life and
Homeostasis
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ANATOMY AND PHYSIOLOGY
 Anatomy and physiology are branches of biology
concerned with the form and functions of the body
 Anatomy: science of the structure and shape of the
body and its parts.
 Physiology: science of the functions of organisms;
subdivisions named by:



Organism involved: human or plant physiology
Organizational level: molecular or cellular physiology
Systemic function: respiratory physiology, neurophysiology, or
cardiovascular physiology
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Branches of Anatomy
 Gross anatomy: study of the body and its parts that relies
only on what the eye can see as a tool for observation
 Microscopic anatomy: study of small body parts with a
microscope
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
Cytology: study of cells
Histology: study of tissues
 Developmental anatomy: study of human growth and
development
 Pathological anatomy: study of diseased body structures
 Systemic anatomy: study of the body by systems
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Levels of Organization
 From Atoms to Organisms
1.
2.
3.
4.
5.
6.
Chemical Level
Cellular Level
Tissue Level
Organ Level
Organ System Level
Organismal Level
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LEVELS OF ORGANIZATION:
Chemical Level
 Organization of chemical structures separates
living material from nonliving material
 Organization of atoms, molecules, and
macromolecules results in living matter—a gel
called cytoplasm
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LEVELS OF ORGANIZATION:
Cellular Level
 Cells: smallest and most numerous units
that possess and exhibit characteristics of
life
 Each cell has a nucleus surrounded by
cytoplasm within a limiting membrane
 Cells differentiate to perform unique
functions
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LEVELS OF ORGANIZATION
Tissue Level
 Tissue: an organization of similar cells
specialized to perform a certain function
 Tissue cells are surrounded by nonliving
matrix
 Four major tissue types
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

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Epithelial
Connective
Muscle
Nervous
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LEVELS OF ORGANIZATION
Organ Level
 Organ: organization of
several different kinds of
tissues to perform a specific
function
 Organs represent discrete
and functionally complex
operational units
 Each organ has a unique
size, shape, appearance, and
placement in the body
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LEVELS OF ORGANIZATION
System Level
 Systems: most complex organizational units of
the body
 System level involves varying numbers and kinds
of organs arranged to perform complex
functions
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Support and movement
Communication, control, and integration
Transportation and defense
Respiration, nutrition, and excretion
Reproduction and development
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Organ System overview
1. Integumentary System
2. Skeletal System
3. Muscular System
4. Nervous System
5. Endocrine System
6. Cardiovascular System
7. Lymphatic System
8. Respiratory System
9. Digestive System
10. Urinary System
11. Reproductive System
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LEVELS OF ORGANIZATION
Organism
 The living human organism is greater than the
sum of its parts
 All the components interact to allow the human
being to survive and flourish
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Maintaining life
Homeostasis
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Necessary Life Functions
 Maintain boundaries
 Movement
 Locomotion
 Movement of substances
 Responsiveness
 Ability to sense changes and react
 Digestion
 Break-down and absorption of nutrients
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Necessary Life Functions
 Metabolism—chemical reactions within the body
 Produces energy
 Makes body structures
 Catabolism- chemical break down of complex molecules into
simpler molecules; releases energy
 Anabolism- chemical reaction that joins simple molecules to
form more complex molecules
 Excretion
 Eliminates waste from metabolic reactions
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Necessary Life Functions
 Reproduction
 Produces future generation
 Growth
 Increases cell size and number of cells
 Nutrients
 Chemicals for energy and cell building
 Includes carbohydrates, proteins, lipids, vitamins, and
minerals
 Oxygen
 Required for chemical reactions
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Survival Needs
 Water
 60–80% of body weight
 Provides for metabolic reaction
 Stable body temperature
 Atmospheric pressure
 Must be appropriate
Interrelationships Among Body Systems
Figure 1.3
Image from: Copyright © 2009 Pearson Education, Inc,. Publishing as Benjamin Cummings
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
Body adjusts important variables from a normal set point in
an acceptable or normal range
Examples of homeostasis:
 Temperature regulation
 Regulation of blood carbon dioxide level
 Regulation of blood glucose level
Input:
Information
sent along
afferent
pathway to
Control
center
Output:
Information sent
along efferent
pathway to activate
Effector
Receptor (sensor)
Change
detected
by receptor
Stimulus:
Produces
change
in variable
Variable
(in homeostasis)
Response of
effector feeds
back to
influence
magnitude of
stimulus and
returns variable
to homeostasis
Figure 1.4
Image from: Copyright © 2009 Pearson Education, Inc,. Publishing as Benjamin Cummings
Input:
Information
sent along
afferent
pathway to
Control
center
Output:
Information sent
along efferent
pathway to activate
Effector
Receptor (sensor)
Change
detected
by receptor
Stimulus:
Produces
change
in variable
Variable
(in homeostasis)
Response of
effector feeds
back to
influence
magnitude of
stimulus and
returns variable
to homeostasis
Image from: Copyright © 2009 Pearson Education, Inc,. Publishing as Benjamin Cummings
Maintaining Homeostasis
 The body communicates through neural and
hormonal control systems

Receptor
Responds to changes in the environment (stimuli)
 Sends information to control center


Control center
Determines set point
 Analyzes information
 Determines appropriate response


Effector

Provides a means for response to the stimulus
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Feedback Mechanisms: Negative Feedback
 Includes most homeostatic control mechanisms
 Shuts off the original stimulus, or reduces its
intensity
 Works like a household thermostat
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
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Are inhibitory
Stabilize physiological variables
Produce an action opposite to the change that activated the system
 Are responsible for maintaining homeostasis
 Are much more common than positive feedback
control systems
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Feedback Mechanisms: Positive Feedback
 Increases the original stimulus to push the variable
farther
 Are stimulatory
 Tend to produce destabilizing effects and disrupt
homeostasis
 Bring specific body functions to swift completion
 In the body this occurs in blood clotting and during the
birth of a baby
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Feedback Mechanisms: Level of Control
 Intracellular control
 Regulation within cells
 Genes or enzymes can regulate cell processes
 Intrinsic control (autoregulation)
 Regulation within tissues or organs
 May involve chemical signals
 May involve other “built in” mechanisms
 Extrinsic control
 Regulation from organ to organ
 May involve nerve signals
 May involve endocrine signals (hormones)
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The Chemical Basis of Life
BASIC CHEMISTRY
 Elements and compounds
 Matter: anything that has mass and occupies space
 Element: simple form of matter; a substance that cannot be broken
down into two or more different substances
 Compound: atoms of two or more elements joined to form chemical
combinations
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Elements in Living Organisms
 The most common elements found in living
organisms include:
 Carbon
(C)
 Oxygen (O)
 Nitrogen (N)
 Hydrogen (H)
 Phosphorus (P)
 Sulfur (S)
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Biochemistry
 Living things require millions of chemical reactions
within the body, just to survive.
 Metabolism = all the chemical reactions occurring in the
body.
 Organic molecules:



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usually associated with living things.
always contain CARBON.
are “large” molecules, with many atoms
always have covalent bonds (share electrons)
 Inorganic compounds: few have carbon atoms and none
have C–C or C–H bonds
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INORGANIC MOLECULES
 Water
 The body’s most abundant and important compound
 Oxygen
 Required to complete decomposition reactions necessary
for the release of energy in the body
 Carbon dioxide
 Produced as a waste product and helps maintain the
appropriate acid-base balance in the body
 Electrolytes
 Large group of inorganic compounds that includes acids,
bases, and salts
 Substances that dissociate in solution to form ions
 Act as buffers
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ORGANIC MOLECULES:
Carbohydrates
 Organic compounds containing carbon, hydrogen,
and oxygen; commonly called sugars and
starches.
 Used for energy and structure
 Includes three types:
Monosaccharide (1 sugar – quick energy)
 Disaccharide (2 sugars – short storage)
 Polysaccharide (many sugars – energy
long storage & form structures)

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ORGANIC MOLECULES:
Lipids
 Insoluble in water (think oil & water)
 Used for energy and structural support
 4 types:
 1-triglycerides (fats & oils)

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2-phospholipids (primary component of cell
membrane)
3-steroids (cell signaling)

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(long-term energy storage, insulation)
cholesterol molecules modified to form sex hormones.
(e.g. testosterone, estrogen, etc.)
4-waxes (protection, prevents water loss)

Used mainly by plants, but also bees, some furry
animals and humans.
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Phospholipids
Steroids
ORGANIC MOLECULES
Proteins
 Most abundant organic compounds
 Chainlike polymers
 Amino acids: building blocks of proteins
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Essential amino acids: eight amino acids that cannot be
produced by the human body
Nonessential amino acids: 12 amino acids that can be
produced from molecules available in the human body
Amino acids consist of a carbon atom, an amino group, a
carboxyl group, a hydrogen atom, and a side chain
Support
structural proteins (e.g., keratin, collagen)
Enzymes
speed up chemical reactions
Transport
cell membranes channels, transporters in blood
(e.g., Hemoglobin)
Defense
antibodies of the immune system
Hormones
cell signaling (e.g., insulin)
Motion
contractile proteins (e.g., actin, myosin)
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Collagen
Antibodies
ORGANIC MOLECULES:
Nucleic Acid
 Nucleotides: building blocks of nucleic acids.
 Each nucleotide contains
(a) phosphate molecule,
 (b) nitrogenous base, and
 (c) 5-carbon sugar

 Several types of nucleic acids, including:
 DNA: deoxyribonucleic acid
Genetic material, double stranded helix
RNA: ribonucleic acid
 Genetic material, single stranded
ATP: adenosine triphosphate
 High energy compound



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DNA
Nucleotide Structure
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