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153 Cards in this Set

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the regulation of body temperature
1. the part of the face or facial region in humans and certain animals that contains the nostrils and the organs of smell and functions as the usual passageway for air in respiration: in humans it is a prominence in the center of the face formed of bone and cartilage, serving also to modify or modulate the voice.
2. this part as the organ of smell
the tube or cavity, with its surrounding membrane and muscles, that connects the mouth and nasal passages with the esophagus
1. Anatomy. a muscular and cartilaginous structure lined with mucous membrane at the upper part of the trachea in humans, in which the vocal cords are located.
2. Zoology. a. a similar vocal organ in other mammals.
b. a corresponding structure in certain lower animals.
the tube in humans and other air-breathing vertebrates extending from the larynx to the bronchi, serving as the principal passage for conveying air to and from the lungs; the windpipe.
Either of two main branches of the trachea, leading directly to the lungs.
Any of the fine, thin-walled, tubular extensions of a bronchus
an air cell of the lungs, formed by the terminal dilation of tiny air passageways
1. Anatomy. a. a muscular, membranous or ligamentous wall separating two cavities or limiting a cavity.
b. the partition separating the thoracic cavity from the abdominal cavity in mammals.
red blood cells
The disk-shaped cells in the blood that contain hemoglobin. The red blood cells supply oxygen to all body cells and remove the carbon dioxide wastes that result from metabolism.
either of the two upper chambers on each side of the heart that receive blood from the veins and in turn force it into the ventricles.
. The chamber on the left side of the heart that receives arterial blood from the left atrium and contracts to force it into the aorta.
A membranous structure in a hollow organ or passage, as in an artery or vein, that folds or closes to prevent the return flow of the body fluid passing through it.
SA node
a specialized bit of heart tissue that controls the heartbeat
AV node
A small mass of specialized cardiac muscle fibers, located in the wall of the right atrium of the heart, that receives heartbeat impulses from the sinoatrial node and directs them to the walls of the ventricles
the normal rhythmical contraction of the heart, during which the blood in the chambers is forced onward.
the normal rhythmical dilatation of the heart during which the chambers are filling with blood.
white blood cells
Colorless cells in the blood that help combat infection. Some white blood cells act as scavengers by engulfing foreign particles (such as bacteria) and destroying them. Others produce antibodies or destroy dead cells.
A minute, nonnucleated, disklike cytoplasmic body found in the blood plasma of mammals that is derived from a megakaryocyte and functions to promote blood clotting
the liquid part of blood or lymph, as distinguished from the suspended elements
a colorless, pungent, suffocating, highly water-soluble, gaseous compound, NH3, usually produced by the direct combination of nitrogen and hydrogen gases: used chiefly for refrigeration and in the manufacture of commercial chemicals and laboratory reagents.
1. Biochemistry. a compound, CO(NH2)2, occurring in urine and other body fluids as a product of protein metabolism.
uric acid
a compound, C5H4N4O3, present in mammalian urine in small amounts, and the principal nitrogenous component of the excrement of reptiles and birds, that in the form of its salts occurs in the joints in gout and as the major constituent of kidney stones.
1. a compact cluster of capillaries.
2. Also called Malpighian tuft. a tuft of convoluted capillaries in the nephron of a kidney, functioning to remove certain substances from the blood before it flows into the convoluted tubule.
bowman's capsule
a membranous, double-walled capsule surrounding a glomerulus of a nephron.
proximal tubule
the convoluted portion of the vertebrate nephron that lies between Bowman's capsule and the loop of Henle, is made up of a single layer of cuboidal cells with striated borders, and functions especially in the resorption of sugar, sodium and chloride ions, and water from the glomerular filtrate called also proximal tubule
loop of henle
the part of a nephron between the proximal and distal convoluted tubules that extends, in a loop, from the cortex into the medulla of the kidney.
a muscular duct or tube conveying the urine from a kidney to the bladder or cloaca.
membranous sac or organ serving as a receptacle for a fluid or air.
the membranous tube that extends from the urinary bladder to the exterior and that in the male conveys semen as well as urine.
the process whereby fluids pass through a filter or a filtering medium
The process of secreting a substance, especially one that is not a waste, from the blood or cells: secretion of hormones; secretion of milk by the mammary glands.
A substance, such as saliva, mucus, tears, bile, or a hormone, that is secreted.
Also called reabsorption. the selective uptake into the bloodstream of substances previously filtered out of the blood
the process by which cells and simple organisms maintain fluid and electrolyte balance with their surroundings.
antidiuretic hormone
Biochemistry. a peptide hormone, synthesized in the hypothalamus and released by the posterior pituitary gland, that stimulates capillary muscles and reduces the flow of urine and increases its concentration.
a hormone produced by the cortex of the adrenal gland, instrumental in the regulation of sodium and potassium reabsorption by the cells of the tubular portion of the kidney
the opening through which an animal or human takes in food.
salivary amylase
an enzyme in the saliva that converts starch into dextrin and maltose.
a thin, valvelike, cartilaginous structure that covers the glottis during swallowing, preventing the entrance of food and drink into the larynx.
a muscular passage connecting the mouth or pharynx with the stomach in invertebrate and vertebrate animals; gullet
the progressive wave of contraction and relaxation of a tubular muscular system, esp. the alimentary canal, by which the contents are forced through the system.
a saclike enlargement of the alimentary canal, as in humans and certain animals, forming an organ for storing, diluting, and digesting food.
hydrochloric acid
hydrogen chloride; a colorless, corrosive gas, HCl, of pungent, suffocating odor. It is made in great quantities in the soda process, by the action of sulphuric acid on common salt. It has a great affinity for water, and the commercial article is a strong solution of the gas in water. It is a typical acid, and is an indispensable agent in commercial and general chemical work.
an enzyme, produced in the stomach, that in the presence of hydrochloric acid splits proteins into proteoses and peptones
a viscous, slimy mixture of mucins, water, electrolytes, epithelial cells, and leukocytes that is secreted by glands lining the nasal, esophageal, and other body cavities and serves primarily to protect and lubricate surfaces.
any of various enzyme precursor molecules that may change into an enzyme as a result of catalytic change.
crystals, occurring in the gastric glands, that during digestion are converted into pepsin.
to cleanse (rooms, wounds, clothing, etc.) of infection; destroy disease germs in.
controlled release
of a substance, as a medicine or insecticide) released or activated at predetermined intervals or gradually over a period of time
the process in the alimentary canal by which food is broken up physically, as by the action of the teeth, and chemically, as by the action of enzymes, and converted into a substance suitable for absorption and assimilation into the body.
the first portion of the small intestine, from the stomach to the jejunum.
Enzymes that degrade protein molecules
an enzyme that converts maltose into glucose and causes similar cleavage of many other glucosides.
an enzyme capable of hydrolyzing lactose into glucose and galactose.
A salt or ester of phosphoric acid
a gland, situated near the stomach, that secretes a digestive fluid into the intestine through one or more ducts and also secretes the hormone insulin.
a proteolytic enzyme of the pancreatic juice, capable of converting proteins into peptone.
a proteolytic enzyme, found in pancreatic juice, that catalyzes the hydrolysis of proteins into polypeptides and amino acids
any of a class of enzymes that break down fats, produced by the liver, pancreas, and other digestive organs or by certain plants.
any of various enzyme precursor molecules that may change into an enzyme as a result of catalytic change.
a precursor of trypsin that is secreted by the pancreas and is activated to trypsin in the small intestine.
a large, reddish-brown, glandular organ located in the upper right side of the abdominal cavity, divided by fissures into five lobes and functioning in the secretion of bile and various metabolic processes.
gall bladder
a pear-shaped, muscular sac attached to the undersurface of the right lobe of the liver, in which bile is stored and concentrated
a bitter, alkaline, yellow or greenish liquid, secreted by the liver, that aids in absorption and digestion, esp. of fats.
large intestine
the broad, shorter part of the intestines, comprising the cecum, colon, and rectum, that absorbs water from and eliminates the residues of digestion.
small intestine
the narrow, longer part of the intestines, comprising the duodenum, jejunum, and ileum, that serves to digest and absorb nutrients.
the part of the nervous system comprising the brain and spinal cord.
the part of the central nervous system enclosed in the cranium of humans and other vertebrates, consisting of a soft, convoluted mass of gray and white matter and serving to control and coordinate the mental and physical actions.
spinal cord
the cord of nerve tissue extending through the spinal canal of the spinal column.
peripheral nervous system
the portion of the nervous system lying outside the brain and spinal cord.
pertaining to or affecting the somatic cells, as distinguished from the germ cells.
skeletal muscle
A usually voluntary muscle made up of elongated, multinucleated, transversely striated muscle fibers, having principally bony attachments
under the control of the autonomic nervous system
pertaining to that part of the autonomic nervous system consisting of nerves that arise from the thoracic and lumbar regions of the spinal cord, and functioning in opposition to the parasympathetic system, as in stimulating heartbeat, dilating the pupil of the eye, etc.
pertaining to that part of the autonomic nervous system consisting of nerves and ganglia that arise from the cranial and sacral regions and function in opposition to the sympathetic system, as in inhibiting heartbeat or contracting the pupil of the eye.
reflex arc
the nerve pathways followed by an impulse during a reflex
Any of several parts branching from the body of a neuron that receive and transmit nerve impulses.
the appendage of the neuron that transmits impulses away from the cell body.
a region where nerve impulses are transmitted and received, encompassing the axon terminal of a neuron that releases neurotransmitters in response to an impulse, an extremely small gap across which the neurotransmitters travel, and the adjacent membrane of an axon, dendrite, or muscle or gland cell with the appropriate receptor molecules for picking up the neurotransmitters.
myelin sheath
a wrapping of myelin around certain nerve axons, serving as an electrical insulator that speeds nerve impulses to muscles and other effectors.
to divide into sharply opposing factions, political groups, etc.: The controversy has polarized voters into proabortion and
resting potential
the potential difference between the two sides of the membrane of a nerve cell when the cell is not conducting an impulse
action potential
the change in electrical potential that occurs between the inside and outside of a nerve or muscle fiber when it is stimulated, serving to transmit nerve signals.
Elimination or neutralization of polarity, as in nerve cells
The restoration of a polarized state across a membrane, as in a muscle fiber following contraction.
The restoration of a polarized state across a membrane, as in a muscle fiber following contraction.
to increase the difference in electric potential across (a cell membrane).
refractory period
a short period after a nerve or muscle cell fires during which the cell cannot respond to additional stimulation.
the acetic acid ester of choline, C7H17NO3, released and hydrolyzed during nerve conduction and causing muscle action by transmitting nerve impulses across synapses
an enzyme, found esp. in the heart, brain, and blood, that hydrolyzes acetylcholine to acetic acid and choline.
a hormone secreted by the adrenal medulla upon stimulation by the central nervous system in response to stress, as anger or fear, and acting to increase heart rate, blood pressure, cardiac output, and carbohydrate metabolism
catecholamine neurotransmitter in the central nervous system, retina, and sympathetic ganglia, acting within the brain to help regulate movement and emotion: its depletion may cause Parkinson's disease.
a neurotransmitter, derived from tryptophan, that is involved in sleep, depression, memory, and other neurological processes
smooth muscle
involuntary muscle tissue in the walls of viscera and blood vessels, consisting of nonstriated, spindle-shaped cells.
cardiac muscle
a specialized form of striated muscle occurring in the hearts of vertebrates.
muscle fiber
one of the structural cells of a muscle
any of the segments of myofibril in striated muscle fibers.
the cytoplasm of a striated muscle fiber
the principal contractile protein of muscle
A cell, such as a white blood cell, that engulfs and absorbs waste material, harmful microorganisms, or other foreign bodies in the bloodstream and tissues.
a histidine-derived amine compound that is released mainly by damaged mast cells in allergic reactions, causing dilation and permeability of blood vessels and lowering blood pressure.
dilatation of the blood vessels, as by the action of a nerve
Any of the nearly colorless cells found in the blood, lymph, and lymphoid tissues, constituting approximately 25 percent of white blood cells and including B cells, which function in humoral immunity, and T cells, which function in cellular immunity.
A substance that when introduced into the body stimulates the production of an antibody. Antigens include toxins, bacteria, foreign blood cells, and the cells of transplanted organs.
any of numerous Y-shaped protein molecules produced by B cells as a primary immune defense, each molecule and its clones having a unique binding site that can combine with the complementary site of a foreign antigen, as on a virus or bacterium, thereby disabling the antigen and signaling other immune defenses.
A preparation of a weakened or killed pathogen, such as a bacterium or virus, or of a portion of the pathogen's structure that upon administration stimulates antibody production or cellular immunity against the pathogen but is incapable of causing severe infection.
passive immunity
immunity resulting from the injection of antibodies or sensitized lymphocytes from another organism or, in infants, from the transfer of antibodies through the placenta or from colostrum.
the tendency of a system, esp. the physiological system of higher animals, to maintain internal stability, owing to the coordinated response of its parts to any situation or stimulus tending to disturb its normal condition or function.
a self-regulatory biological system, as in the synthesis of some hormones, in which the output or response affects the input, either positively or negatively.
a region of the brain, between the thalamus and the midbrain, that functions as the main control center for the autonomic nervous system by regulating sleep cycles, body temperature, appetite, etc., and that acts as an endocrine gland by producing hormones, including the releasing factors that control the hormonal secretions of the pituitary gland.
posterior pituitary
a small, somewhat cherry-shaped double structure attached by a stalk to the base of the brain and constituting the master endocrine gland affecting all hormonal functions in the body, consisting of an anterior region (anterior pituitary or adenohypophysis) that develops embryonically from the roof of the mouth and that secretes growth hormone, LH, FSH, ACTH, TSH, and MSH, a posterior region (posterior pituitary or neurohypophysis) that develops from the back of the forebrain and that secretes the hormones vasopressin and oxytocin, and an intermediate part (pars intermedia), derived from the anterior region but joined to the posterior region, that secretes the hormone MSH in lower
endocrine gland
Any of various glands producing hormonal secretions that pass directly into the bloodstream. The endocrine glands include the thyroid, parathyroids, anterior and posterior pituitary, pancreas, adrenals, pineal, and gonads. Also called ductless gland.
a gland, situated near the stomach, that secretes a digestive fluid into the intestine through one or more ducts and also secretes the hormone insulin.
a polypeptide hormone, produced by the beta cells of the islets of Langerhans of the pancreas, that regulates the metabolism of glucose and other nutrients.
a hormone secreted by the pancreas that acts in opposition to insulin in the regulation of blood glucose levels
At, near, or on the kidneys.
a hormone secreted by the adrenal medulla upon stimulation by the central nervous system in response to stress, as anger or fear, and acting to increase heart rate, blood pressure, cardiac output, and carbohydrate metabolism.
hormone produced by the cortex of the adrenal gland, instrumental in the regulation of sodium and potassium reabsorption by the cells of the tubular portion of the kidney
An organ in animals that produces gametes, especially a testis or ovary.
female gonad or reproductive gland, in which the ova and the hormones that regulate female secondary sex characteristics develop.
the male gonad or reproductive gland, either of two oval glands located in the scrotum.
A substance, usually a peptide or steroid, produced by one tissue and conveyed by the bloodstream to another to effect physiological activity, such as growth or metabolism.
any of a large group of fat-soluble organic compounds, as the sterols, bile acids, and sex hormones, most of which have specific physiological action.
any of numerous, highly varied organic molecules constituting a large portion of the mass of every life form and necessary in the diet of all animals and other nonphotosynthesizing organisms, composed of 20 or more amino acids linked in a genetically controlled linear sequence into one or more long polypeptide chains, the final shape and other properties of each protein being determined by the side chains of the amino acids and their chemical attachments: proteins include such specialized forms as collagen for supportive tissue, hemoglobin for transport, antibodies for immune defense, and enzymes for metabolism.
the female gonad or reproductive gland, in which the ova and the hormones that regulate female secondary sex characteristics develop.
either of a pair of tubes that transport the ova from the ovary to the exterior, the distal ends of which form the uterus and vagina in higher mammals.
the enlarged, muscular, expandable portion of the oviduct in which the fertilized ovum implants and develops or rests during prenatal development; the womb of certain mammals.
The neck.
A neck-shaped anatomical structure, such as the narrow outer end of the uterus.
the passage leading from the uterus to the vulva in certain female mammals
corpus luteum
a ductless gland developed within the ovary by the reorganization of a Graafian follicle following ovulation
the roundish reproductive body produced by the female of certain animals, as birds and most reptiles, consisting of an ovum and its envelope of albumen, jelly, membranes, egg case, or shell, according to species.
A cell from which an egg or ovum develops by meiosis; a female gametocyte.
an elongated organ on the posterior surface of a testis that constitutes the convoluted beginning of the vas deferens
vas deferens
the duct that transports the sperm from the epididymis to the penis.
seminal vesicle
either of two small saclike glands, located on each side of the bladder in males, that add nutrient fluid to semen during ejaculation.
the number of inhabitants, dwellings, or the like, per unit area
exponential growth
Growth of a system in which the amount being added to the system is proportional to the amount already present: the bigger the system is, the greater the increase
The capturing of prey as a means of maintaining life
the close external resemblance of an organism, the mimic, to some different organism, the model, such that the mimic benefits from the mistaken identity, as seeming to be unpalatable or harmful
a number of persons or things following one another in order or sequence
the stable and self-perpetuating end stage in the ecological succession or evolution of a plant and animal community.
a state, process, or instance of combustion in which fuel or other material is ignited and combined with oxygen, giving off light, heat, and flame
a region so arid because of little rainfall that it supports only sparse and widely spaced vegetation or no vegetation at all
the coniferous evergreen forests of subarctic lands, covering vast areas of northern North America and Eurasia
one of the vast, nearly level, treeless plains of the arctic regions of Europe, Asia, and North America.
tropical rain forest
a rain forest in a tropical area
primary producer
any green plant or any of various microorganisms that can convert light energy or chemical energy into organic matter
primary consumer
an animal that feeds on plants; a herbivore
secondary consumer
a carnivore that feeds only upon herbivores
tertiary consumer
a carnivore at the topmost level in a food chain that feeds on other carnivores; an animal that feeds only on secondary consumers
greenhouse effect
an atmospheric heating phenomenon, caused by short-wave solar radiation being readily transmitted inward through the earth's atmosphere but longer-wavelength heat radiation less readily transmitted outward, owing to its absorption by atmospheric carbon dioxide, water vapor, methane, and other gases; thus, the rising level of carbon dioxide is viewed with concern.
acid rain
precipitation, as rain, snow, or sleet, containing relatively high concentrations of acid-forming chemicals, as the pollutants from coal smoke, chemical manufacturing, and smelting, that have been released into the atmosphere and combined with water vapor: harmful to the environment.
the processes by which an area becomes a desert