Heb 1351 Exam 1

Front 1

autocrine

Back 1

hormones that act on cells that synthesized them

Front 2

endocrine

Back 2

hormones that act on neighboring cells

Front 3

paracrine

Back 3

hormones that act on cells or organs to which they are carried in bloodstream

Front 4

neuroendocrine

Back 4

these hormones are synthesized in a nerve cell which releases the hormones adjacent to the target cell or into the bloodstream

Front 5

binding globulins (proteins)

Back 5

bind hormones in blood, often with high affinity and/or specificity, for transporty

Front 6

albumin

Back 6

binding protein, binds many hormones including thyroid hormone and the sex hormones

Front 7

free hormone

Back 7

a measure of unbound hormone in the bloodstream, physiologically active and available, in equilibrium with concentration of total hormone

Front 8

ion channel

Back 8

mediate active transport with gates activated by receptors or voltage changes through cell membrane

Front 9

protein phosphorylation

Back 9

membrane receptors activate proteins via phosphorylation

Front 10

G protein

Back 10

secondary messenger that is activated (either stimulatory or inhibitory) and then affects other proteins

Front 11

nuclear receptor

Back 11

steroid hormones diffuse in and bind to intracellular receptors (the HRE on DNA in the nucleus) to affect gene transcription

Front 12

protein kinase

Back 12

phosphorylates proteins in cellular response

Front 13

adenylate cyclase

Back 13

activated by G protein to convert ATP to cAMP, located on membrane but does not itself bind hormone

Front 14

cyclic AMP

Back 14

activates protein kinases

Front 15

signal amplification

Back 15

downstream cascade through which a single hormone binding results in a strong effect because many cAMP and PKA can be made at once

Front 16

inositol triphosphate

Back 16

G protein triggers PLP which breaks PIP2 into IP3 and DAG. IP3 generates from the ER increased Ca2+, and together DAG promotes activation of PKC

Front 17

intracellular calcium

Back 17

intracellular Ca2+ from ER activates inositol triposphate system

Front 18

heat shock protein

Back 18

intracellular receptors are bound to HSP which then dissociates when the hormone binds to the receptor

Front 19

zinc finger

Back 19

the DNA binding region of an intracellular receptor

Front 20

DNA binding domain

Back 20

one of the two main regions of the intracellular receptiors, which consists of two zinc fingers

Front 21

hormone binding domain

Back 21

one of the two main regions of the intracellular receptor, hydrophobic

Front 22

hypothalamus

Back 22

base of brain, controls homeostasis, consists of many nuceli

Front 23

anterior pituitary

Back 23

from roof of mouth, receives hormones via the portal system, part of parvocellular secretory system

Front 24

posterior pituitary

Back 24

from base of brain (neural), part of magnocellular system

Front 25

magnocellular secretory system

Back 25

PVN and SON nuclei project into post pit, producing oxytocin and vasopressin

Front 26

parvocellular secretory system

Back 26

PVN and smaller nuclei that produce hormones that control ant pit

Front 27

hypophyseal portal system

Back 27

vascular link between hypothalamus and ant pit

Front 28

hypothalamic peptide hormones

Back 28

GnRH and related stimulating hormones from hypothalamus, trademark synthesis

Front 29

pulsatile release

Back 29

GnRH and subsequent hormones must be released in specific pulsatile way to be effective

Front 30

postive feedback

Back 30

MORE of the hormone is produced in response to rising levels, "runaway"

Front 31

negative feedback

Back 31

production of hormone decreased by rising levels, attenuates system like furnace

Front 32

Wolffian duct

Back 32

develop in male under influence of T (and if tetis produces MIH)

Front 33

Mullerian duct

Back 33

develop in females in absense of production of T

Front 34

SRY

Back 34

the male sex-determining gene on the Y chromosome, switches on testicular development via TDF

Front 35

Mullerian duct inhibiting factor

Back 35

produced by testis (Sertoli cells), causes atrophy of Mullerian ducts

Front 36

DHT

Back 36

synthesized from T, results in development of external genitalia

Front 37

theca cells

Back 37

receptors for LH, production of androgens

Front 38

granulosa cells

Back 38

receptors for FSH, aromatizes androgens into estrogens

Front 39

aromatase

Back 39

converts androgens into estrogens

Front 40

inhibin

Back 40

produced by granulosa cells, feeds back negatively on FSH production

Front 41

FSH

Back 41

promotes follicular growth and induces LH receptors

Front 42

LH

Back 42

produces androgens, surge in females to aid in rupture

Front 43

hCG

Back 43

after ovum fertilized the syncitiotrophoblast begins to secrete hCG which takes over the role of LH and stimulates the production of progesterone

Front 44

oxytocin

Back 44

involved in contraction of mammary gland cells which leads to milk discharge, may become suckling reflex

Front 45

prolactin

Back 45

controlled by emptying, results in milk production, inhibited by dopamine

Front 46

leydig cells

Back 46

synthesis of T in response to LH, interstitial cells between seminiferous tubulues

Front 47

sertoli cells

Back 47

FSH and T together stimulate spermatogenesis

Front 48

pregnenolone

Back 48

precursor is cholesterol, precursor to all steroid hormones

Front 49

desmolase

Back 49

converts cholesterol to pregnenolone

Front 50

TRH

Back 50

produced by the hypothalamus nuclei, stored in median eminence, stimulates production of TSH in AP, negative feedback by T3

Front 51

TSH

Back 51

produced by AP, stimulates thyroid gland to release T3 and T4

Front 52

thyronines

Back 52

thyroid hormones T3 and T4

Front 53

T3 and T4

Back 53

iodine reacts with tyrosine residues and then comination results in T3 and T4, activation occurs when TSH stimulation results in deiodination

Front 54

adrenal medulla

Back 54

modified ganglion of chromaffin cells, secretes catecholamines EP and NE

Front 55

adrenal cortex

Back 55

secretes steroid hormones from zonas glomerulosa(mineralcorticoids), fasciculata (glucocorticoids), and reticularis(sex steroids)

Front 56

catacholamine

Back 56

EP and NE, secreted by adrenal medulla upon neural signal

Front 57

epinephrine

Back 57

fight or flight hormone, release caused by stressors

Front 58

tyrosine hydroxylase

Back 58

enzyme for conversion of tyrosine to dopa, a precursor to catacholamines (rate limiting step)

Front 59

phenlethanolamine N-methyltransferase (PNMT)

Back 59

enzyme for conversion of NE to EP

Front 60

cortisol

Back 60

glucocorticoid in humans that acts on carbohydrate metabolism in response to stress, released from adrenal cortex in response to ACTH

Front 61

CRH

Back 61

produced by hypothalamus nuclei, stimulates release of ACTH from AP

Front 62

ACTH

Back 62

produced in AP, stimulates release of glucocorticoids from adrenal cortex, acts through AC system

Front 63

pro-opiomelanocortin (POMC)

Back 63

CRH stimulates transcription and translation of POMC protein which then acts with Ca2+ (also form cAMP) to produce ACTH (ie it is CLEAVED)

Front 64

circadian rhythm

Back 64

cortisol released in daily rhythm based on external environment

Front 65

cell cycle

Back 65

process of cell growth and division, stimulated by hormones GH, IGF1, insluin, prolactin and PL

Front 66

growth hormone

Back 66

released by AP, stimulates metabolism and production of IGFs

Front 67

IGF-1

Back 67

stimulates protein synthesis, lipolysis, and bone growth

Front 68

alpha cells

Back 68

in islets of Langerhans, secrete glucagon

Front 69

beta cells

Back 69

in islets of Langerhans, secrete insulin

Front 70

c-peptide of insulin

Back 70

connecting peptide in proinsulin from which insulin is cleaved

Front 71

glucagon

Back 71

secreted when glucose levels are low, promotes break down of glycogen to produce glucose, also conversion of amino acids to glucose and lipolysis

Front 72

insulin

Back 72

secreted when glucose levels are high, stimulates cellular uptake of glucose for storage as glycogen, also conversion of fatty acids into lipids and uptake of amino acids

Front 73

lateral hypothalamic area

Back 73

satiety center, lesions cause intense feeding behavior

Front 74

ventromedial hypothalamic area

Back 74

feeding center, lesions cause appetite loss

Front 75

leptin

Back 75

ob gene product, expressed only by fat cells, leptin signals satiety

Front 76

Cole's paradox

Back 76

the relationship, in fitness terms, between survival and fertility is that having equal fitness for living forever and for living one year only reqires having ONE extra offspring! so why increase longevity...?

Front 77

energy allocation tradeoffs

Back 77

want to increase fitness through natural selection but because of limiting resources organisms must choose where to invest: growth, maintenance, reproduction

Front 78

reproductive effort

Back 78

proportion of energy allocated to reproduction (0 to 1)

Front 79

survival-fertility tradeoff

Back 79

energy can be allocated, generally, towards either survival or fertility. aim is to maximize fitness. represented as curves of costs and benefits. what is the reproductive value of the offspring...

Front 80

seminiferous tubule

Back 80

contains sertoli cells for maturation of sperm

Front 81

spermatogonium

Back 81

near the basement membrane of the seminiferous tubule, still diploid and mitotic

Front 82

spermatocyte

Back 82

start developing into sperm and migrate towards lumen

Front 83

sperm count

Back 83

normally high but does not seem to be related to fertility about a certain level, perhaps related to frequency of ejaculation, AGE AND TEMP

Front 84

tetis size

Back 84

relates to amount of seminiferous tubule and thus to sperm production, larger weight for competing male systems

Front 85

oogonium

Back 85

immature ovum, formed in large numbers by mitosis during fetal development

Front 86

follicle

Back 86

aggregations of cells found in the ovary that contain the developing ova

Front 87

primary oocyte

Back 87

first meiotic division (not completed), leads to one polar body and secondary oocyte, GCs cuboidal, zone pellucida forms

Front 88

preantral follicle

Back 88

primary oocyte begins to build a layer of theca cells

Front 89

antral follicle

Back 89

follicle interior filled with fluid, GCs proliferating, TC secreting androgens

Front 90

Graafian follicle

Back 90

mature follicle with large antrum and cumulous oophorous, E2 levels plataeu...surge

Front 91

corpus luteum

Back 91

"yellow body" of T and G cells, temporarily endocrine, develops after ovulation and secrets progesterone to maintain pregnancy, later becomes scar tissue if egg not fertilized

Front 92

cummulus oophorus

Back 92

cluster of granulosa cells surrounding ovum in mature follicle, released with ovum at ovulation

Front 93

zona pellucida

Back 93

another membrane surrounding oocyte, develops in primary follicle, protects and then interacts with sperm

Front 94

germinal vesicle breakdown

Back 94

occurs with continuation of meiosis at ovulation, prevented temporarily by granulosa cells?

Front 95

gap junctions

Back 95

connections between granulosa cells and oocyte that allow for cellular communication

Front 96

acrosome

Back 96

cap on sperm that contains enzymes necessary for fertilization of egg

Front 97

acrosome reaction

Back 97

sperm acrosome contacts cumulus oophorus and then penetrates zona pellucida and then docks and begins to enter egg

Front 98

oocyte activation

Back 98

after acrosome reaction egg machinery quickly turned on (intracellular Ca2+ released)

Front 99

Gadgil and Bossert's solution to Cole's paradox

Back 99

limiting resources of energy and time must be allocated to growth, maintenance, and reproduction so as to maximize fitness (curves)

Front 100

Levran et al.'s alternative mechanism for the LH surge

Back 100

rather than estrogen increase (positive feedback) suggested that estrogen levels plateau at max follicle size and it is the removal of negative feedback that stimulates LH surge of accumulated hormone

Front 101

Charnov and Berrigan's theory of the scaling of metabolism and its relationship to life history

Back 101

big animals compared to small: live longer, mature and reproduce slower. because need more maintenance and thus have less energy to allocate to growth and reproduction