Chp. 1-4

Homeostasis

steady state of body systems that living organisms maintain

Catabolism

the metabolic process of breaking down complex molecules into simpler ones, releasing energy in the process.

Anabolism

the metabolic process of building up complex molecules from simpler ones, usually requiring energy.

Your body can assemble, by utilizing energy, the complex chemicals it needs by combining small molecules derived from the foods you eat

ATP

Stores and releases energy

composed of a ribose sugar, an adenine base, and three phosphate groups.

releases free energy when its phosphate bonds are broken, and thus supplies ready energy to the cell. More is produced in the presence of oxygen (O₂) than in pathways that do not use oxygen.

ATP process

The cell stores energy in the synthesis (anabolism) of ATP, then moves the ATP molecules to the location where energy is needed to fuel cellular activities. Then the ATP is broken down (catabolism) and a controlled amount of energy is released, which is used by the cell to perform a particular job.

cell

smallest independently functioning unit of a living organism.

organelles

specialized structures within a cell that perform distinct functions, such as energy production and protein synthesis.

tissue

a group of many similar cells (though sometimes composed of a few related types) that work together to perform a specific function.

organ

an anatomically distinct structure of the body composed of two or more tissue types. Each one performs one or more specific physiological functions.

organ system

a group of organs that work together to perform major functions or meet physiological needs of the body.

Differentation

where unspecialized cells become specialized in structure and function to perform certain tasks in the body

Set point

the physiological value around which the normal range fluctuates.

Normal range

the restricted set of values that is optimally healthful and stable.

ex: body temperature 98.6

negative feedback

a mechanism that reverses a deviation from the set point.

maintains body parameters within their normal range.

effector

is the component in a feedback system that causes a change to reverse the situation and return the value to the normal range.

positive feedback

intensifies a change in the body’s physiological condition rather than reversing it. A deviation from the normal range results in more change, and the system moves farther away from the normal range.

normal only when there is a definite end point.

Ex: pooping and childbirth

integumentary system

encloses internal body structures

site of many sensory receptors

hair, skin, nails

skeletal system

supports the body

enables movement

cartilage, bones, joints

muscular system

enables movement

helps maintain body temperature

skeletal muscles, tendons

nervous system

detects and processes sensory information

activates bodily responses

brain, spinal cord, peripheral nerves

endocrine system

secretes hormones

regulates bodily processes

pituitary gland, thyroid gland, pancreas, adrenal glands, testes, ovaries

cardiovascular system

delivers oxygen and nutrients to tissues

equalizes temperature in the body

heart, blood vessels

lymphatic system

returms fluid to blood

defends against pathogens

thymus, lymph nodes, spleen, lymphatic vessels

respiratory system

removes carbon dioxide from the body

delivers oxygen to blood

nasal passage, trachea, lungs

digestive system

processes food for use by the body

removes wastes from undigested food

stomach, liver, gall bladder, large intestine, small intestine

urinary system

controls water balance in the body

removes waste from blood and excretes them

kidneys, urinary bladder

organism

a living being that has a cellular structure and that can independently perform all physiologic functions necessary for life.

Metabolsim

the sum of all anabolic and catabolic reactions that take place in the body

prone

face-down position

supine

face up position

sagittal plane

is the plane that divides the body or an organ vertically into right and left sides. If this vertical plane runs directly down the middle of the body, it is called the midsagittal or median plane. If it divides the body into unequal right and left sides, it is called a parasagittal plane or less commonly a longitudinal section.

frontal (coronal) plane

the plane that divides the body or an organ into an anterior (front) portion and a posterior (rear) portion.

transverse plane

the plane that divides the body or organ horizontally into upper and lower portions. plane that produces cross sections

oblique plane

intersects the body at an angle and is not parallel or perpendicular to any of the other three commonly used planes.

dorsal (posterior) cavity

cranial and spinal cavaties

Ventral (anterior) cavity

thoracic and abdominopelvic cavaties

pleura

the serous membrane that encloses the pleural cavity; the pleural cavity surrounds the lungs

serous membrane

(also referred to a serosa) is one of the thin membranes that cover the walls and organs in the thoracic and abdominopelvic cavities.

parietal layer

lines the walls of the body cavity (pariet- refers to a cavity wall).

visceral layer

covers the organs (the viscera).

element

a pure substance that is distinguished from all other matter by the fact that it cannot be created or broken down by ordinary chemical means.

Together, just four elements make up more than 95 percent of the body’s mass. These include

oxygen, carbon, hydrogen, and nitrogen

compound

a substance composed of two or more elements joined by chemical bonds.

atom

the smallest quantity of an element that retains the unique properties of that element

typically has the same number of positively charged protons and negatively charged electrons.

proton

number determines the element

electron

The number of negatively-charged electrons that “spin” around the nucleus at close to the speed of light equals the number of protons.

atomic number

the number of protons (and electrons) in the nucleus of the atom, identifies the element.

mass number

the sum of the number of protons and neutrons in its nucleus.

isotope

one of the different forms of an element, distinguished from one another by different numbers of neutrons.

electron shell

a layer of electrons that encircle the nucleus at a distinct energy level.

valence shell

atom’s outermost electron shell.

atoms (except hydrogen andf helium) and single electron shells and are most stable when their valence shells are full (8 electrons)

bond

is a weak or strong electrical attraction that holds atoms in the same vicinity.

molecule

A more or less stable grouping of two or more atoms held together by chemical bonds

compound

When a molecule is made up of two or more atoms of different elements

H₂O

ion

An atom that has an electrical charge; whether positive (cation) or negative (anion)

ionic bond

formed by the attraction of ions of opposite charges

table salt

covalent bond

share electrons in a mutually stabilizing relationship. Like next-door neighbors whose kids hang out first at one home and then at the other, the atoms do not lose or gain electrons permanently

polar molecule

a molecule that contains regions that have opposite electrical charges. occur when atoms share electrons unequally, in polar covalent bonds.

hydrogen bond

is formed when a weakly positive hydrogen atom already bonded to one electronegative atom (for example, the oxygen in the water molecule) is attracted to another electronegative atom from another molecule. In other words, hydrogen bonds always include hydrogen that is already part of a polar molecule.

Mechanical energy

When you lift a brick into place on a wall, your muscles provide the mechanical energy that moves the brick.

Radiant energy

The body uses the ultraviolet energy of sunlight to convert a compound in skin cells to vitamin D, which is essential to human functioning. The human eye evolved to see the wavelengths that comprise the colors of the rainbow, from red to violet, so that range in the spectrum is called “visible light.”

Electrical energy

supplied by electrolytes in cells and body fluids, contributes to the voltage changes that help transmit impulses in nerve and muscle cells.

synthesis reaction

a chemical reaction that results in the synthesis (joining) of components that were formerly separate

A + B —> AB

decomposition reaction

chemical reaction that breaks down or “de-composes” something larger into its constituent parts

AB —> A + B

exchange reaction

chemical reaction in which both synthesis and decomposition occur, chemical bonds are both formed and broken, and chemical energy is absorbed, stored, and released

A + BC —> AB + C // AB + CD —> AC + BD

catalyst

a substance that increases the rate of a chemical reaction without itself undergoing any change.

enzyme

a catalyst composed of protein or ribonucleic acid (RNA)

lower the activation energy in a chemical reaction

inorganic compound

is a substance that does not contain both carbon and hydrogen

organic compound

a substance that contains both carbon and hydrogen

solution

consists of a solvent that dissolves a substance called a solute.

homogenous (molecules are distributed evenly throughout the solution)

colloid

a mixture that is somewhat like a heavy solution. Consists of tiny clumps of molecules large enough to make the liquid mixture opaque (because the particles are large enough to scatter light).

milk and cream

suspension

is a liquid mixture in which a heavier substance is suspended temporarily in a liquid, but over time, settles out.

Acid

Substance that releases hydrogen ions (H⁺) in solution

Base

Substance that releases hydroxyl ions (OH^–) in solution, or one that accepts H⁺ already present in solution

Buffer

A solution of a weak acid and its conjugate base. Can neutralize small amounts of acids or bases in body fluids.

Functional group

A group of atoms linked by strong covalent bonds and tending to function in chemical reactions as a single unit.

Ttightly knit “cliques” whose members are unlikely to be parted.

Functional groups important in human physiology

Hydroxyl, carboxyl, amino, methyl

Carbohydrate

molecule composed of carbon, hydrogen, and oxygen

saccharides (sugars)

lipid

one of a highly diverse group of compounds made up mostly of hydrocarbons

hydrophobic compounds that provide body fuel and are important components of many biological compounds.

triglyceride

one of the most common dietary lipid groups, and the type found most abundantly in body tissues. This compound, which is commonly referred to as a fat, is formed from the synthesis of two types of molecules

major fuel source for the body

protein

is an organic molecule composed of amino acids linked by peptide bonds.

found in the keratin in the epidermis of skin that protects underlying tissues, the collagen found in the dermis of skin, in bones, and in the meninges that cover the brain and spinal cord.

components of many of the body’s functional chemicals, including digestive enzymes in the digestive tract, antibodies, the neurotransmitters that neurons use to communicate with other cells, and the peptide-based hormones that regulate certain body functions (for instance, growth hormone).

RNA

ribose-containing nucleotide that helps manifest the genetic code as protein.

tissue

a group of cells found together in the body.

epithelial tissue

the sheets of cells that cover exterior surfaces of the body, line internal cavities and passageways, and form certain glands.

lining of GI tract organs and other hollow organs

skin surface (epidermis)

connective tissue

implies, binds the cells and organs of the body together and functions in the protection, support, and integration of all parts of the body.

fat and other soft padding tissue

bone

tendon

muscle tissue

excitable, responding to stimulation and contracting to provide movement, and occurs as three major types: skeletal (voluntary) muscle, smooth muscle, and cardiac muscle in the heart.

cardiac muscles

smooth muscle

skeletal muscle

nervous tissue

also excitable, allowing the propagation of electrochemical signals in the form of nerve impulses that communicate between different regions of the body

brain, spinal cord, nerves

ectoderm

endoderm

mesoderm

tissue membrane

a thin layer or sheet of cells that covers the outside of the body (for example, skin), the organs (for example, pericardium), internal passageways that lead to the exterior of the body (for example, mucosa of stomach), and the lining of the moveable joint cavities. There are two basic types of tissue membranes: connective tissue and epithelial membranes

connective tissue membrane

formed solely from connective tissue

These membranes encapsulate organs, such as the kidneys, and line our movable joints.

synovial membrane

type of connective tissue membrane that lines the cavity of a freely movable joint.

For example, they surround the joints of the shoulder, elbow, and knee.

Intracellular fluid (ICF)

the fluid interior of the cell.

Extracellular fluid (ECF)

the fluid environment outside the enclosure of the cell membrane.

Interstitial fluid

the term given to extracellular fluid not contained within blood vessels.

integral protein

protein that is embedded in the membrane.

channel protein

an example of an integral protein that selectively allows particular materials, such as certain ions, to pass into or out of the cell.

receptor

a type of recognition protein that can selectively bind a specific molecule outside the cell, and this binding induces a chemical reaction within the cell.

ligand

the specific molecule that binds to and activates a receptor.