A&P Exam 1 Chapters 1-3

Anatomy

The study of body form/structure

Physiology

The study of body function

Microscopic Anatomy

deals with structures too small to be seen with the naked eye

Histology

the study of the microscopic structure of tissues

Gross Anatomy

Study of structures that can be seen with the naked eye

Levels of Structural Organization

atom, cell, tissue, organ, organ system, organism

11 organ systems of the body

1. Integumentary

2. Skeletal

3. Muscular

4. Nervous

5. Endocrine

6. Cardiovascular

7. Lymphatic

8. Respiratory

9. Digestive

10. Urinary

11. Reproductive

In the following name a part, function, and element within the system

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integumentary system

Skin, hair, and nails,

protects

skeletal system

bones (sternum, ribs, tibea), cartilages, and joints,

supports/structures and protects

Muscular System

muscles attached to bones (pectoralis major),

contracts

Nervous System

brain, spinal cord, nerves, and sensory receptors

fast-acting control!!

reaction to external stimuli and communication

Endocrine System

glands include the pituitary, thyroid, parathyroids, adrenals, thymus, pancreas, pineal,

slow-acting control using hormones

Cardiovascular System

heart and blood vessels,

delivers oxygen, nutrients, hormones

Lymphatic System

lymphatic vessels, lymph nodes, spleen, and tonsils,

recollects leaked fluids

Respiratory System

nasal passages, pharynx, larynx, trachea, bronchi, and lungs, moves only oxygen and carbon dioxide

Digestive System

oral cavity (mouth), esophagus, stomach, small and large intestines, and rectum,

Breaks down food, nutrient absorption, eliminates waste

Urinary System

kidneys, ureters, bladder,

eliminates nitrogenous wastes, acid-base balance/water-electrolyte balance, regulates blood pressure

Reproductive System

ovaries, uterine tubes, uterus

produces offspring

Necessary Life Functions

1. Maintaining boundaries

2. Movement

3. Responsiveness

4. Digestion

5. Metabolism

6. Excretion

7. Reproduction

8. Growth

Maintaining boundaries

Separation between internal and external environments must exist

Movement

movement of substances and locomotion

Responsiveness

Sensing and reacting to a change inside or outside the body

Digestion

Break down and absorption of nutrients

Metabolism

chemical reactions within the body

Break down complex molecules into smaller ones

Build larger molecules from smaller ones

Produces energy

Regulated by hormones

Excretion

Elimination of waste products from metabolism (sweat, urine, feces)

Reproduction

occurs at the cellular and the organismal level

On cellular level—new cells are used for growth and repair

On organismal level—the reproductive system handles the task

Growth

Increases cell size or body size (through increasing the number of cells)

Hormones play a major role

Survival Needs

nutrients, oxygen, water, normal body temperature, atmospheric pressure

nutrients

Chemicals used for energy and cell building

Include carbohydrates, proteins, lipids, vitamins, and minerals

oxygen

Required for chemical reactions• Made available by the cooperation of the respiratory and cardiovascular systems

water

60 to 80 percent of body weight

Most abundant chemical in the human body

Provides fluid base for body secretions and excretions

normal body temperature

37ºC (98.6ºF)

Below this temperature, chemical reactions slow and stop

Above this temperature, chemical reactions proceed too rapidly

Atmospheric pressure

Must be appropriate for gas exchange

cooperative physiology

All systems work together and are reliant on each other

Homeostasis

maintained equilibrium/balance of internal conditions (never perfect)

Necessary for normal body functioning and to sustain life

managed by Nervous system and Endocrine system

homeostatic imbalance

a disturbance in homeostasis resulting in disease

3 components of homeostasis control mechanisms

receptor, control center, and effector

Receptor

Nerves

Responds to changes in the environment (stimuli)

Sends information to control center

Control Center

Spinal Chord and Brain

Determines set point

Analyzes information

Determines appropriate response

Effector

Organs and Muscles

Provides a means for response to the stimulus

Information flows from control center to effector

afferent vs efferent

Afferent carries impulses toward the region of interest. For instance, any input coming into the brain is considered to be afferent. (sensory)

Efferent carries impulses away from the region of interest. For instance, any output from the brain will be efferent (motor)

Feedback Mechanisms

The way an organism monitors its needs and maintains equilibrium/homeostasis.

Negative feedback

most common mechanism of homeostasis.

change in a physiological variable that is being monitored triggers a response that counteracts the initial fluctuation.

Shuts off the original stimulus or reduces its intensity.

Positive feedback

Rare in the human body

Increases the original stimulus to push the variable farther until homeostasis is achieved

Reaction occurs at a faster rate

(blood clotting and during the birth of a baby)

Matter

anything that occupies space and has mass

3 states of matter

solid, liquid, gaseous

Ways matter may be changed

physically, chemically

Physical Matter Change

Changes do not alter the basic nature of a substance

Examples include changes in the state of matter (solid, liquid, or gas)

chemical matter change

Changes alter the chemical composition of a substance

Energy

the ability to do work

Has no mass and does not take up space

kinetic energy

energy is in the act of doing work

potential energy

energy is inactive or stored

Forms of energy

chemical, electrical, mechanical, radiant

Chemical energy

is stored in chemical bonds of substances

When the bonds are broken, potential energy is unleashed and becomes kinetic energy

electrical energy

results from movement of charged particles

Mechanical energy

energy directly involved in moving matter

Example: opening a door

Radiant energy

travels in waves; energy of the electromagnetic spectrum

What does ATP do

traps the chemical energy of food in its bonds

Elements

the fundamental units of matter

periodic table contains complete list of known ones

96 % of the body is made from which four elements

Oxygen (O)—most common; 65% of the body's mass

Carbon (C)

Hydrogen (H)

Nitrogen (N)

Molecule

two or more atoms of the same elements combined chemically

H (atom) + H (atom) → H2 (molecule)

Reactants vs products

Reactants are substances that start a chemical reaction. Products are substances that are produced in the reaction.

Compound molecule

two or more atoms of different elements combined chemically

4H + C → CH4 (methane)

Chemical reactions occur

when atoms combine with or dissociate from other atoms

Chemical bonds

are energy relationships involving interactions among the electrons of reacting atoms

electron shells (energy levels)

layers on which electrons circle around the nucleus

Electrons closest to the nucleus are most strongly attracted to its positive charge

Distant electrons further from the nucleus are likely to interact with other atoms

electron shell properties

Shell 1 can hold a maximum of 2 electrons

Shell 2 can hold a maximum of 8 electrons

Shell 3 can hold a maximum of 18 electrons

Bonding involves interactions only between electrons in the outermost (valence) shell

Atoms with full valence shells do not form bonds

inert elements

have their valence shell fully occupied by electrons and are unreactive

reactive elements

Atoms will gain, lose, or share electrons to complete their outermost orbitals when their valence shell is incomplete

Chemical bonding helps atoms achieve a stable valence shell

Types of chemical bonds

ionic, covalent, hydrogen

Ionic bonds

Form when electrons are completely transferred from one atom to another

Allow atoms to achieve stability through the transfer of electrons

Weak bonds

Ions

positively and negatively charged atoms

Result from the loss or gain of electrons

Anions have negative charge due to gain of electron(s) Cations have positive charge due to loss of electron(s)

Tend to stay close together because opposite charges attract

Covalent bonds

Atoms become stable through shared electrons

Electrons are shared in pairs

Single covalent bonds share one pair of electrons

Double covalent bonds share two pairs of electrons

Nonpolar covalent bonds

Electrons are shared equally between the atoms of the molecule

Electrically neutral as a molecule

Example: carbon dioxide

Polar covalent bonds

Electrons are not shared equally between the atoms of the molecule

Molecule has a positive and negative side, or pole

Example: water

Hydrogen bonds

Extremely weak chemical bonds

Formed when a hydrogen atom is attracted to the negative portion, such as an oxygen or nitrogen atom, of a polar molecule

Responsible for the surface tension of water

Important for forming intramolecular bonds, as in protein structure

synthesis reaction

Atoms or molecules combine to form a larger, more complex molecule A+B > AB

Ex: Amino acids form protein chain

Energy is absorbed for bond formation

Underlies all anabolic (building) activities in the body

decomposition reaction

Molecule is broken down into smaller molecules AB > A + B (break down into building blocks)

Ex: Glycogen broken into glucose

Chemical energy is released

Underlies all catabolic (destructive) activities in the body

Exchange reaction

Parts of the reacting molecules are shuffled around to produce new products

Involves simultaneous synthesis and decomposition reactions as bonds are both made and broken

AB + C > AC + B

Ex: ATP > ADP losing 1 P

Switch is made between molecule parts, and different molecules are made

Chemical reactions are

reversible

Reversibility is indicated by a double arrow

When arrows differ in length, the longer arrow indicates the more rapid reaction or major direction of progress

Chemical reaction rate influencers

Temperature, # of particles, particle size, catalysts

Increased temperature

increased kinetic energy of particles

Increased concentration of reacting particles

increase the number of collisions

Smaller particle size

Smaller particles have more kinetic energy and move faster than larger ones, hence they take part in more collisions.

presence of a catalyst

decrease the amount of energy the molecules need to interact by holding the reactants in the proper positions to interact

Inorganic compounds

Lack carbon

Tend to be small, simple molecules

Include: water, salts, and many (not all) acids and bases

Water vital properties

Most abundant inorganic compound in the body

Accounts for two-thirds of the body's weight

High heat capacity

Polarity/solvent properties

Chemical reactivity

Cushioning

high heat capacity of water

Water absorbs and releases a large amount of heat before it changes temperature

Prevents sudden changes in body temperature

Polarity/solvent properties

"universal solvent" (dissolve smaller amounts of solutes)

Solutes are solids, liquids, or gases that are dissolved or suspended by solvents

makes solvents available to body

Chemical reactivity

Water is an important reactant in some chemical reactions

Reactions that require water are known as hydrolysis reactions

Example: water helps digest food or break down biological molecules

Cushioning

Water serves a protective function

Examples: cerebrospinal fluid protects the brain from physical trauma, and amniotic fluid protects a developing fetus

Salts

Ionic compound

Easily dissociate (break apart) into ions in the presence of water

Vital to many body functions

Example: sodium and potassium ions are essential for nerve impulses

ALL salts are electrolytes

Electrolytes

ions that conduct electrical currents

Acids

Electrolytes that dissociate (ionize) in water and release hydrogen ions (H+)

Proton (H+) donors

Example: HCl → H+ + Cl-

Strong acids ionize completely and liberate all their protons

Weak acids ionize incompletely

0-6 More H+ than OH-

Bases

Electrolytes that dissociate (ionize) in water and release hydroxyl ions (OH-)

Proton (H+) acceptors

Example: NaOH → Na+ + OH-

8-14 Fewer H+ than OH-

Neutral

7

the number of hydrogen ions exactly equals the number of hydroxyl ions

Buffers

chemicals that can regulate pH change

pH

measures relative concentration of hydrogen (and hydroxide) ions in body fluids

pH scale is based on the number of protons in a solution

scale runs from 0(acid) to 14(base)

Each successive change of 1 pH unit represents a tenfold change in H+ concentration

Neutralization reaction

Type of exchange reaction in which acids and bases react to form water and a salt

Example: NaOH + HCl → H2O + NaCl