Biology Test 4

Front 1

adrenal cortex

Back 1

the outer part of the adrenal gland, which secretes steroid hormones that regulate metabolism and salt balance

Front 2

adrenal gland

Back 2

a mammalian endocrine gland, adjacent to the kidney; secretes hormones that function in water regulation and in the stress response.

Front 3

adrenal medulla

Back 3

the inner part of the adrenal gland, which secretes epinephrine and norepinephrine in the stress response

Front 4

adrenocorticotropic hormone (ACTH)

Back 4

a hormone, secreted by the anterior pituitary, that stimulates the release of hormones by the adrenal cortex, especially in response to stress

Front 5

aldosterone

Back 5

a hormone, secreted by the adrenal cortex, that helps regulate ion concentration in the blood yb stimulating the reabsorption of sodium by the kidneys and sweat glands

Front 6

amino acid derived hormone

Back 6

a class of hormone that is synthesized by the body from single amino acids. Exmaples include epinephrine and thyroxine.

Front 7

androgen

Back 7

a male sex hormone

Front 8

anterior pituitary

Back 8

a lobe of the pirtuitary gland that produces prolactin and growth hormone as well as hormones that regulate hormone production in other glands.

Front 9

antidiuretic hormone (ADH)

Back 9

a hormone produced by the hypothalamus and released into the bloodstream by the posterior pituitary when blood volume is low; increase the permeabilit of the distal tubule and the collecting duct to water, allowing more water to be reabsorbed into the bloodstream.

Front 10

cortisol

Back 10

a steroid hormone released ino the bloodstream by the adrenal cortex in response to stress. Cortisol helps the body cope with short-term stressors by raising blood glucose levels

Front 11

diabetes mellitus

Back 11

a disease characterized by defects in the production, release, or reception of insulin; characterized by high blood glucose levels that fluctuate with sugar intake.

Front 12

Duct

Back 12

the tube or opening through which exocrine secretions are released

Front 13

endocrine disrupter

Back 13

environmental pollutants that interfere with endocrine function, often by disrupting the action of sex hormones

Front 14

endocrine gland

Back 14

a dcutless, hormone producting gland consisting of cells that release their secretions into the extracellular fluid from which the secretions diffuse into nearby capillaries.

Front 15

endocrine hormone

Back 15

chemcial messages produced by specialized cells and released into circulatory system. They cause a prolonged or temporary change in target cells bearing specific receptors for these hormones.

Front 16

endocrine system

Back 16

an animal's organ system for cell-to cell communication, composed of hormones and the cells that secrete them and receive them

Front 17

epinephrine

Back 17

a hormone, secreted by teh adrenal medulla, that is released in response to stress and that stimulates a variety of responses, including the release of glucose from liver and an increase in heart rate.

Front 18

exocrine gland

Back 18

a gland that releases its secretions into ducts that lead to the outside of the body or into the digestive tract

Front 19

follicle-stimulating hormone

Back 19

a hormone produced by teh anterior pitutary, that stimulates spermatogenesis in males and the development of the follicle in females

Front 20

glucagon

Back 20

a hormone, secreted by the pancreas, tat increases blood sugar by stimulating the breakdown of glycogen (to glucose) in the liver.

Front 21

glucocorticoid

Back 21

a class of hormones, released by adrenal cortex in resposne to teh presence of ACTH, that make additional energy available to the body by stimulating the synthesis of glucose

Front 22

goiter

Back 22

a swelling of the neck caused by iodine deficiency, which affects the functioning of the thyroid gland and its hormones.

Front 23

growth hormone

Back 23

a hormone, released by the anterior pituitary, that stimulates growth, especially of the skeleton

Front 24

hypothalamus

Back 24

a region of the brain that controls the secretory activity of the pituitary gland; synthesizes, stores, and releases certain peptide hormones; directs autonmic nervous system responses.

Front 25

inhibiting hormone

Back 25

a hormone, secreted by teh neurosecretory cells of the hypothalamus, that inhibits the release of specific hormones from the anterior pituitary.

Front 26

insulin

Back 26

a hormone, secreted by the pancreas, that lowers blood sugar by stimulating many cells to take up glucose and by stimulating the liver to convert glucose to glycogen.

Front 27

islet cell

Back 27

a cell in the endocrine portion of the pancreas that produces either insulin or glucagon.

Front 28

local hormone

Back 28

a general term for messenger molecules produced by most cells and released into the cells' immediate vicinity. Local hormones, which include prostaglandins and cytokines, influences nearby cells bearing appropriate receptors.

Front 29

luteninizing homrone (LH)

Back 29

a hormone, produced by the anterior pituitary, that stimulates testosterone production in males and the development of the follicle, ovulation, and the production of the corpus luteum in females.

Front 30

melanocyte-stimulating hormone (MSH)

Back 30

a hormone, released by the anteiror pituitary, that regulates the activity of skin pigments in some vertebrates.

Front 31

neurosecretory cell

Back 31

a specialized nerve cell that synthesizes and releases hormones

Front 32

norepinehrine

Back 32

a neurotransmitter, released y neurons of the parasympathetic nervous system, that prepares the body to respond to stressful situations; also called noradrenaline

Front 33

oxytocin

Back 33

a hormone, released by the posterior pituitary, that stimulates the contraction of uterine and mammary gland muscles

Front 34

pancreas

Back 34

a combined exocrine and endocrine gland located in the abdominal cavity next to teh stomach. The endocrine portion secretes the hormones insulin and glucagon, which regulate glucose concentrations in the blood. The exocrine portion secretes enzymes for fat, carbohydrates and protein digestion into the small intestine and neutralizes the acidic chyme.

Front 35

peptide hormone

Back 35

a hormone consisting of a chain of amino acids; includes small proteins that function as hormones

Front 36

pituitary gland

Back 36

an endocrine gland, located at the base of the brain, that produces several hormones, many of which influence the activity of other glands

Front 37

posterior pituitary

Back 37

a lobe of the pituitary gland that is an outgrowht of the hypothalamus and that releases antidirutetic hormone and oxytocin.

Front 38

prolactin

Back 38

a hormone, released by anterior pituitary, that stimulates milk production in human females

Front 39

prostaglandin

Back 39

a family of modified fatty acid hormones manufactured by may cells of the body.

Front 40

receptor

Back 40

a cell that reponds to an environmental stimulus by changing its electrical potential, also, a protein moleucle in a plasma membrane that inds to another molecule, triggering metabolic or electrical changes in a cell.

Front 41

releasing hormone

Back 41

a hormone, secreted by the hypothalamus, that causes the release of specific hormones by the anterior pituitary.

Front 42

second messenger

Back 42

an intracellular chemcial, uch as cyclic AMP, that is syntehisized or relased within a cell in response to the binding of a hormone or neuotransmitter (the first messenger) to receptors on the cell surface; brings about specific changes in the metabolism of the cell

Front 43

steroid hormone

Back 43

a class of hormone whose chemical structure (four fused carbon rings with various functional groups) resembles cholesterol; steroids, which are lipids, are secreted by the ovaries and placenta, the testes, and the adrenal cortex.

Front 44

target cell

Back 44

a cell on which a particular hormone exerts its effect.

Front 45

thyroid gland

Back 45

an endocrine galnd located in frotn of the larynx in the neck, that secrets the hormones thyroxine (affecting metabolic rate) and calcitonin (regulating calcium ion concentration in the blood)

Front 46

thyroid stimulating hormone

Back 46

a hormone, released by the anterior pituitary, that stimulates the thyroid gland to release hormones

Front 47

thyroxine

Back 47

a hormone, secreted by the thyroid gland, that stimulates and regulates metabolism

Front 48

action potential

Back 48

a rapid change from a negative to a positive electrical potential in a nerve cell. This signal travels along an axon without a change in amplitude

Front 49

autonomic nervous system

Back 49

the part of the peripheral nervous system of vertebrates that synapses on glands, internal organs, and smooth muscle and produces largely involuntary responses

Front 50

axon

Back 50

a long extension of a nerve cell, extending from the cell body to synaptic ending on other nerve cells or on muscles

Front 51

blood-brain barrier

Back 51

relatively impermeable capillaires of the brain that protect the cells of the brain from potentially damaging chemicals that reach the bloodstream

Front 52

brain

Back 52

the part of the central nervous system of vertebrates that is enclosed within the skull

Front 53

cell body

Back 53

the part of a nerve cell in which most of the common cellular organelles are located; typically a site of integration of inputs to the nerve cell

Front 54

central nervous systems

Back 54

in vertebrates, the brain and spinal cord

Front 55

cerebellum

Back 55

the part of the hindbrain of vertebrates that is concerned with coordinating movements of the body

Front 56

cerebral cortex

Back 56

a thin layer of neurons on the surface of the vertebrate cerebrum, in which most neural processing and coordination of activity occurs

Front 57

cerebral hemisphere

Back 57

one of two nearly symmetrical halves of the cerebrum, connected by a broad band of axons, the corpus callosum

Front 58

cerbrospinal fluid

Back 58

a clear fluid, produced within the ventricles of the brain, that fills the ventricles and cushions the brain and spinal cord

Front 59

cerebrum

Back 59

the part of the forebrain of vertebrates that is concerned with seonsry processing, the direction of motor output, and the coordination of most bodily activityies; consists of two nearly sysmmetrical hales (the hemispheres) connected by a broad band of axons, the corpus callosum.

Front 60

chemorecptor

Back 60

a sensory receptor that responds to chemicals from the environemnt; used in the chemical senses of taste and smell.

Front 61

cochlea

Back 61

a coiled, bony, fluid filled tube found in the mammalian inner ear; contains receptors (hair cells) that respond to the vibration of sound.

Front 62

cone

Back 62

a cone-shaped photoreceptor cell in the vertebrate retina; not as sensitive to light as are the rods. The three types of cones are most sensitive to different colors of light and provide color vision

Front 63

corpus callosum

Back 63

the band of axons that connect the two cerebral hemispheres of vertebrates.

Front 64

dendrite

Back 64

a branched tendril that extends outward from the cell body of a neuron, specialized to repsond to signals from the external environment or from other neurons

Front 65

effector

Back 65

a part of the body (normally a msucle or gland) that carries out responses as directed by the nervous system.

Front 66

excitatory postsynaptic potential

Back 66

If the postsynaptic neruon becomes less negative, then its resting potential will move closer to threshold, and it will be more likely to fire an action potential.

Front 67

forebrain

Back 67

during development, the anterior portion of the brain. In mammals, the forebrain differentiates into the thalamus the limbic system, and the cerebrum. In humans, the cerebrum contains about half of all the neruons in the brains

Front 68

ganglion

Back 68

a cluster of neurons

Front 69

gray matter

Back 69

the outer portion of the brain and inner region of the spinal cord; composed largely of neruon cell bodies, which give this area a grey color

Front 70

hair cell

Back 70

a type of mechanoreceptor cell found i the inner ear tat produces an electrical signal when stiff "hairlike" cilia projecting from the surface of the cell are bent. Hair cells in the cochlea respond to sound vibrtions; those in the vestibular system respond to motion and gravity.

Front 71

hindbrain

Back 71

the posterior portion of the brain, containing the medulla, pons, and cerebellum

Front 72

hypothalamus

Back 72

a region of the brain that controls the secretory activity of the pituitary gland; synthesizes, stores, and releases certain peptide hormones; directs autonomic nervous system responses

Front 73

inhibitory postsynaptic potential

Back 73

If the postsynaptic neuron becomes more negative, its resting potentail moves farther away from threshold, reducing its likelihood of firing an action potential.

Front 74

intensity

Back 74

the strength of stimulation or response

Front 75

interneuron

Back 75

which receive signals from many sources, including sensory neurons, homrones, neurons that store memories, and many others. Based on this input internuerons often activate motor neurons.

Front 76

mechanoreceptor

Back 76

a receptor that responds to mechanical defomration, such as that caused by pressure, touch, or vibration

Front 77

medulla

Back 77

the part of the hindbrain of vertebrates that controls automatic activities such as breathing, swallowing, heart rate, and blood pressure

Front 78

meninges

Back 78

three layers of connective tissue that surround the brain

Front 79

midbrain

Back 79

during development, the central portion of the brain; contains an important relay center, the reticular formation

Front 80

motor neutron

Back 80

a neuron that receives instructions from sensory neurons or internerons and activates effector organs, such as muscles or glands.

Front 81

myelin

Back 81

a wrapping of insulating membranes of specialized nonneurla cells around the axon of a vertebrate nerve cell; increases the speed of conduction of action potentials

Front 82

nerve

Back 82

a bundle of axons of nerve cells, bound together in a sheath

Front 83

neuron

Back 83

a single nerve cell

Front 84

neurotransmitter

Back 84

a chemical that is released by a nerve cell close to a seocnd nerve cell, a muscle, or a gland cell and that influences the activity of the second cell.

Front 85

optic nerve

Back 85

the nerve leading from the eye to the brain, carrying visual information

Front 86

pain receptor

Back 86

a receptor cell that responds to certain chemicals that are produced as a result of tissue damage, such as potassium ions or bradykinin, and is responsible for the sensation of pain

Front 87

paraympathetic division

Back 87

the division of the autonomic nervous system that produces largely involuntary responses related to teh maintenance of normal body functions, such as digestion

Front 88

peripheral nerve

Back 88

a nerve that links the brain and spinal cord to the rest of the body.

Front 89

peripheral nervous system

Back 89

in vertebrates, the part of the nervous system that connects teh central nervous system to the rest of the body

Front 90

photopigment

Back 90

a chemical substance in photorecetpor cells that, when struck by light, changes in molecular conformation

Front 91

photoreceptor

Back 91

a receptor cell that responds to light; in vertebrates, rods, and cones

Front 92

pons

Back 92

a portion of the hindbrain, just above teh medulla, that contains neurons that influence sleep and the rate and pattern of breathing.

Front 93

postsynaptic neuron

Back 93

at a synapse, the nerve cell that changes its electrical potentail in response to a chemical released by another

Front 94

postsynaptic potential

Back 94

an electrical signal produced in a postsynaptic cell by transmission across the synapse; it may be excitatory (EPSP), making the cell more likely to produce an action potential, or inhibitory (IPSP), tending to inhibit an action potential

Front 95

presynaptic neuron

Back 95

a nerve cell that releases a chemical (the neurotransmitter) at a synapse, causing changes in the electrical activity of another (postsynaptic) cell.

Front 96

primary motor areas

Back 96

command movements in corresponding areas of the body by stimulating the motor neurons in the spinal cord that innervate the muscles.

Front 97

primary sensory areas

Back 97

regions where signals orginating in sensory organs such as the eyes and ears are received and converted into subjective impressions.

Front 98

receptor

Back 98

a cell that responds to an enviromental stimulus (chemcicals, sound, light, PH) by changing its electrical potentail; also, a protein molecule in a plasma membrane that binds to another molecule, triggering metabolic or electrical changes in a cell.

Front 99

receptor potential

Back 99

an electrical potential change in a receptor cell, produced in responses to the reception of an environmetnal stimulus (chemcials, sound, light, ehat, and so on). The size of the receptor potential is proportional to the intensity of the stimulus.

Front 100

reflex

Back 100

a simple, sterotyped movement, of part of the body that occurs automatically in response to a stimulus.

Front 101

resting potential

Back 101

a negative electrical potentail in unstimulated nerve cell.

Front 102

retina

Back 102

a multilayered sheet of nerve tissue at the rear of camera-type eyes, composed of photorecetpor cells plus associated nerve cells that refine the photoreceptor information and transmit it to the optic nerve

Front 103

rod

Back 103

a rodshaped photorecetpor cell in the vertebrate retina, sensitive to dim light but no involved in color vision

Front 104

sensory neuron

Back 104

a nerve cell that responds to a stimulus from the internal or external environment.

Front 105

sensory receptor

Back 105

a cell specialized to respond to particular internal or external enviroental stimuli by producing an electrical potential

Front 106

somatic nervous system

Back 106

that portion of the peripheral nervous system that controls voluntary movment by activating skeletal muscles

Front 107

smell

Back 107

the olfactory sense that allows animals to respond to odorous, airborne chemicals in their external environments.

Front 108

spinal chord

Back 108

the part of the central nervous system of vertebrates that extends from the base of the brain to the hips and is protected by the bones of the vertebral column; contains the cell bodies of motor neurons that form synapses with skeltal msucles, the circuitory for some simple reflex behaviors, and axons that communicate with the brain

Front 109

sympathetic division

Back 109

the division of the autonomic nervous system that produces largely involuntary responses that prepare the body for stressful or highly energetic stiuations

Front 110

synapse

Back 110

the site of communication between nerve cells. At a synapse, one cell (presynaptic) normally releases a chemical (the neruotransmitter) that changes the electrical potentail of the second (postsynaptic) cell.

Front 111

synaptic terminal

Back 111

a swelling at the branched ending of an axon; where the axon forms a snapse.

Front 112

taste

Back 112

a chemcial sense for substances disolved in water or saliva; in ammals, pereceptions of sweet, sour, bitter, salty, and umami produced by the stimulation of receptors on the tongue.

Front 113

taste bud

Back 113

a cluster of taste receptor cells and supporting cells that is located in a small pit beneath the surface of the tongue and that communicates with the mouth through a small pore. The human tongue has about 10,000 taste buds.

Front 114

thermoreceptor

Back 114

a sensory receptor that responds to changes in tempertaure

Front 115

threshold

Back 115

the electrical potential (less negative than the resting potential) at which an action potentail is triggered

Front 116

white matter

Back 116

the portion of the brain and spianl cord that consists largely of myelincovered axons and that give these areas a white appearance.