Biocore 485 Unit 1 - Endocrinology

homeostasis

homeostasis

internal constancy and the physiological regulatory systems that automatically make adjustments to maintain it

hyperthyroidism (grave’s disease)

disease with symptoms of high temp, perspiration, weight loss, irritability, high blood pressure, and orbitopathy

hypothyroidism (hashimoto’s disease)

disease with symptoms of weight gain, being cold, and low energy

supraoptic nucleus

neurosecretory cell that synthesizes vasopressin for release in the posterior pituitary

paraventricular nucleus

neurosecretory cell that synthesizes oxytocin for release in the posterior pituitary

alpha cells

cells in islets of the pancreas that produce glucagon

hypoglycemic effect

a decrease in blood glucose; i.e. caused by insulin

hyperglycemic effect

an increase in blood glucose; i.e. caused by glucagon

alveoli

hollow glandular structures that produce milk

stimulates myometrium to form gap junctions and receptors for oxytocin

two roles of estrogen in pregnancy

placenta

organ that allows juxtaposition of maternal + fetal bloodstreams (but blood does not mix)

upper oviduct

fertilization occurs in the _____

implantation

entry of the early embryo in the matrix of the endometrium

nitric oxide (NO)

immediate mediator of an erection that causes dilation of blood vessels in a positive feedback loop

prostate, bulbourethral, seminal

semen contains sperm and secretions from the _____ gland, _____ gland, and _____ vesicles

GnRH

puberty starts when _____-secreting cells become active

capacitation

final maturing of sperm in the reproductive tract to make them capable of rapid forward swimming and fertilization

luteinizing hormone (LH)

secretion of testosterone by leydig cells is stimulated by _____

FSH, testosterone

production of sperm by sertoli cells is stimulated by ____ and ____

corpus luteum

without a functional _____, concentrations of progesterone, estrogen, and inhibin decrease to low levels

androgen

generally male sex hormones, like testosterone; produced by theca cells and then converted into estrogen by granulosa cells

granulosa

FSH binds to _____ cells and stimulates production of aromatase so androgens can be converted into estrogen by aromatization

early

during the _____ follicular phase, estrogen exerts negative feedback on FSH + LH

late

during ____ follicular phase, estrogen causes increased LH, FSH, and GnRH

estrogen

hormone that stimulates growth of the endometrium and stimulates endometrial cells to produce receptors for progesterone

ovulation

blood concentration of LH and FSH peak at _____

theca cells

initial target of LH in women, that stimulates them to produce androgens

atresia

when all other follicles besides the dominant one undergo programmed cell death

zona pellucida

the noncellular layer of glycoproteins the primary oocyte surrounds itself with

epinephrine, norepinephrine, CRH, vasopressin, ACTH

hormones released with stress response

glucocorticoids

during stress response, ____ inhibit the release of FSH, LH, TSH, and GH from the anterior pituitary

photoperiod

number of hours of sunlight in a 24 hour cycle; when increased it signals some animals to reproduce

primordial follicle

each primary oocyte that become enclosed in a single layer of somatic cells

folliculogenesis

when a subset of primordial follicles is recruited to mature each cycle

synergism

one hormone amplifying the effect of the other

permisiveness

when the presence of one hormone is required for the other hormone to exert its full effect on the target tissue

antagonism

when one hormone opposes the action of another; eg. epinephrine + glucagon; dopamine + prolactin

parvocellular neuron

neurons in the hypothalamus that are small and secrete releasing and inhibiting hormones that are carried in the portal to the anterior pituitary; for example releases TRH

axis

two or more hormone secreting tissues that together form a hierarchical control system

direct acting hormone

group of anterior pituitary hormones that exert their principal effects on nonendocrine tissues; eg. GH, prolactin,

tropic hormone

group of hormones secreted by the anterior pituitary that control other endocrine tissues located throughout the body; eg. TSH, ACTH, LH, FSH

peptide

all hormones synthesized and secreted by the anterior pituitary are ____ hormones

magnocellular neurons

the neurons that synthesize vasopressin and oxytocin in the hypothalamus and secrete them in the pars nervosa/posterior pituitary; the paraventricular and supraoptic neurons

pars nervosa

pregnenolone

the six carbon side chain cleaved off of cholesterol to form several other steroid hormones; this change occurs in the mitochondria

preprohormone

large precursor molecule for a hormone, usually a peptide that needs postttranslational modifications before being the functional hormone

iodothyronine

amine hormone derived from tyrosine and synthesized in the thyroid gland; rich in iodine; thyroxine (T4) and triiodothyronine (T3)

catecholamine

amine hormone derived from tyrosine that serves as neurotransmitters or hormones; eg. epinephrine, norepinephrine, dopamine

melatonin

amine hormone derived from tryptophan; secreted from the pineal gland, influences circadian and seasonal rhythms and promotes sleep

peripheral activation

conversion of a hormone after secretion to a more physiologically potent form

autocrine hormone

hormone that diffuses into extracellular fluid to bind to receptors on the same cell; does not enter the blood; eg. insulin or IGF-1

paracrine hormone

hormone that binds to receptors on cells in the neighborhood of the cell that released it; does not enter the blood; eg. testosterone in the testes, estrogen in the ovaries

nonneural endocrine cell

cells other than neurons that synthesize and secrete hormones; also called epithelial cells; typically stimulated by other hormones

neurohemal organ

organ made up of axon terminals of neurosecretory cells in association with well-bred capillaries in which the axon terminals store neurohormone to secrete; eg. hypothalamus

hormone

chemical substance that is produced and released by endocrine cells, carried throughout the body in blood, and exerts regulatory influence on other distant cells

conformity

when an animal permits internal and external conditions to be equal

regulation

when an animal maintains internal constancy in the face of external variability

acute response

responses exhibited during the first minutes or hours after an environmental change

chronic response

responses expressed following prolonged exposure to new environmental conditions

nervous, endocrine

____ control is fast and addressed; ____ control is slow and broadcast

exocrine gland

gland that has outflow tubes called ducts and their secretions flow out by ducts

endocrine gland

gland that secretes products directly into surrounding extracellular fluids, which can diffuse into the blood and capillaries

oviducts

ovaries

fimbriae

ovarian ligament

endometrium

myometrium

cervix

broad ligament

theca cells

granulosa cells

oocyte

zona pellucida

corpus luteum

follicle

seminiferous tubules

testis

epididymus

vas deferens

hypothalamus

pancreas

thyroid

pituitary

parathyroid

adrenal

hypothalamus

median eminence

infundibular stalk

posterior pituitary

anterior pituitary

paraventricular neuron

supraoptic neuron

sensor

in a negative feedback system, the part that senses a change in the variable

integrator

in a negative feedback system, the part that compares the sensed input value to the reference value (set point); also called control center

effector

a tissue, organ, or cell that carriers out functions under the direction of the nervous system or another physiological control system; in a negative feedback system, makes adjustments to the variable

steroid hormone

nonpolar hormones synthesized on demand from cholesterol, secreted by diffusion through the cell membrane and circulated in the blood bound to carrier molecules; typically bind to intracellular receptors of the target cells and exert actions through genomic means

peptide hormone

hormone made of assemblages of amino acids and soluble in water, have receptors on the cell membrane and utilize second messengers

amine hormone

chemical signals derived from the amino acids tyrosine or tyrptophan

hormone binding protein

proteins in the blood that bind to lipid-soluble hormones to transport them, prevent rapid inactivation and extend half-lives