Flashcards in Chapter 2: The Endocrine System Deck (70):
1
intracrine
peptide hormones or growth factors that bind and act inside cells either after internalization by the cells or retention in their cells synthesis
2
autocrine
pertaining to a signal secreted by a cell into the environment that affects the transmitting cell
3
paracrine
a form of cellular communication in which a cell releases a product that induces changes in a nearby cell
4
ectocrine
a parahormonal chemical substance that is secreted (usually by an invertebrate organism) into its immediate environment (air or water) which alters physiology or behavior of the recipient individual
5
endocrinology
the scientific study of endocrine glands and their hormones
6
neurohormone
a hormone that is released into the blood from a neurotransmitter rather than from an endocrine gland
7
neurosecretory cells
a cell in the central nervous system that secretes its product beyond the synapse to affect function in other cells
8
neuroendocrinology
the scientific study of the interaction between the nervous system and the endocrine system
9
endocrine gland
a ductless gland from which hormones are released into the blood system in response to specific physiological signals
10
exocrine gland
a gland that has a duct through which it is product is secreted into adjacent organs or the environment
11
vesicle
a secretory granule or sac within a cell in which hormones or neurotransmitter molecules are stored
12
exocytosis
the extrusion of secretion of substance from a cell by the fusion of a vesicle membrane within the cell membrane
13
carrier protein
one of several different plasma proteins that bind to hormones of low solubility (primarily thyroid and steroid hormones), providing a transport system for them
14
hypothalamus
a part of the diencephalon located just below the thalamus that is important in the regulation of autonomic and endocrine function
15
pituitary gland
an endocrine gland that sits below the hypothalamus and has two distinct anatomical components, the anterior pituitary and the posterior pituitary, each derived from different embryological origins and having different functional roles in the endocrine system
16
thyroid gland
a doubled-lobed endocrine gland located on or near the trachea or esophagus in vertebrates that secretes several hormones important in metabolism, including trilodo-thyronine and thyroxine
17
pancreas
a composite vertebrate bland with both endocrine and exocrine functions
18
adrenal glands
paired, dual compartment endocrine glands in vertebrates consisting of a medulla and a cortex
19
pineal gland
an endocrine gland (also called the epiphysis) located in mammals between the telencephalon and diencephalon, that secretes melatonin, a hormone important in the regulation of daily and seasonal cycles
20
gonad
an endocrine organ that produces sex steroids and gametes; the ovaries and testes are gonads
21
testes
the male gonads, which produce steroid hormones and sperm
22
ovaries
the female gonads, which produce estrogen, progestin and ova
23
placenta
a specialized organ produced by the mammalian embryo that is attached to the uterine wall and serves to provide nutrients, hormones and energy to the fetus
24
peptide hormones
a class of hormones consisting of a relative short chain of amino acids residues
25
protein hormones
a class of hormones consisting of a long chain of amino acid residues
26
biological half-life
the amount of time required to remove half of a hormone or other substance from the blood
27
nuclei
a collection of nerve cell bodies in the brain
28
neurosecretory cells
cells in the central nervous systems that secrete their products beyond the synapse to affect function in other cells
29
dopamine
a neurotransmitter produced primarily in the forebrain and diencephalon that acts in the basal ganglia, olfactory system, and some parts of the cerebral cortex
30
anterior pituitary
front part of the endocrine gland that extends from the base of the brain and secretes a number of tropic hormones in response to hormonal signals from the hypothalamus
31
posterior pituitary
the rear part of the endocrine gland that extends from the base of the brain and stores and releases oxytocin and vasopressin, which are produced in the hypothalamus
32
portal system
a special closed blood circuit in which two beds of capillaries are connected by a vein, thus the flow of blood is in one direction only
33
releasing hormones
one of several polypeptides released from the hypothalamus that increase or decrease the release of hormones from the anterior pituitary gland
34
tropic hormones
hormones from the anterior pituitary that stimulate various physiological processes, either by acting directly on target tissues or by causing other endocrine glands to release hormones
35
prohormone
a molecule that can act as a hormone itself or can be converted into another hormone with different properties
36
vasopressin/ antidiuretic hormone
also known as ADH. A nonapeptide released from the posterior pituitary gland that increases blood pressure during serious blood loss
37
follicles
an epithelial cell-lined sac or compartment of the thyroid gland, ovary, or other structure
38
thyroxine (T4)
the primary hormone secreted from the thyroid gland; it acts to increase oxidation rates in tissues
39
triiodothyronine (T3)
A tyrosine-based hormone that is produced by the thyroid gland and acts to increase the basal metabolic rate, affect protein synthesis, and increase sensitivity to catecholamines
40
parathyroid gland
separate endocrine tissue associated with the thyroid gland; produces hormones involved in calcium metabolism
41
islets of Langerhans
Islands of endocrine tissue nested throughout the exocrine tissue of the pancreas.
42
glucagon
a protein hormone that is secreted by the alpha-cells of the islets of Langerhans in response to low blood glucose levels
43
adrenal medulla
the inner portion of the endocrine organ that sits above the kidneys in vertebrates and secretes epinephrine and norepinephrine.
44
adrenal cortex
the outer layer(s) of the endocrine organ that sits above the kidneys in vertebrates and secretes steroid hormone
45
chromaffin cells
cells that make and store epinephrine secretory vesicles
46
zona glomerulosa
the outermost zone of the adrenal cortex, consisting of whorls fo epithelial cells. Aldosterone is released from these cells as an indirect response to low blood sodium levels
47
zona fasciculata
the middle (and largest) zone of the adrenal cortex, consisting of orderly bands of epithelial cells. Glucocorticoid hormones are released from these cells in response at ACTH stimulation from the anterior pituitary
48
zona reticularis
the innermost zone of the adrenal cortex, consisting of disorganized arrangement of epithelial cells. Sex steroid hormones are often released from this zone
49
pinealocytes
the primary cells of the pineal gland that produce and secrete melatonin
50
steroid hormones
a class of structurally related fat-soluble chemicals that are often derived cholesterol and are characterized by three six-carbon rings plus one conjugated five-carbon ring
51
cholesterol
a white crystalline substance found in animal tissue, and an important part of cell membranes, cholesterol is precursor to steroid hormones
52
prenenolone
A C21 corticoid prohormone that is the obligatory precursor for all other steroid hormones in vertebrates
53
progestins
a class of C21 steroid hormones, so named for their progestational, or pregnancy-maintaining, effects in mammals
54
corticoids
a class of C21 steroid hormones secreted primarily from the adrenal cortices
55
glucocorticoids
one of the two types of corticoids secreted from the adrenal cortices, often released in response to stressful stimuli
56
mineralcorticoids
one of the two types of corticoids secreted from the adrenal cortices, important in ion exchanged and water metabolism
57
corticosterone
glucocorticoid produced in the adrenal cortices of most rodents and birds
58
cortisol
the principal glucocorticoid produced in the adrenal cortices of primates, including humans
59
aldosterone
a mineralocorticoid that causes the kidneys to retain sodium
60
androgens
the primary steroidal product secreted from the testes
61
testosterone
the primary androgen secreted by most vertebrate animals
62
andostenedione
the primary sex hormone secreted by the human adrenal cortex
63
aromatization
the process of converting an androgen molecule to an estrogen molecule via the enzyme aromatase
64
neurosteroids
steroids that are synthesized in the central nervous system (CNS) and the peripheral nervous systems (PNS), independently of the steroidogenic activity of the endocrine glands
65
monoamines
a hormone or neurotransmitter that contains one amine group
66
catecholamines
hormones that are derived from tyrosine and secreted primarily from the adrenal medulla
67
ephinephrine
a catecholamine produced in the adrenal medulla that increases cardiac tone and glucose levels
68
norephinephrine
a substance that can act as either a hormone or neurotransmitter; secreted by the adrenal medulla and the nerve endings of the sympathetic nervous system
69
serotonin
a neurotransmitter from the tryptophan; the precursor to melatonin formation in the pineal gland
70