Regulation of Reproduction Flashcards
hormone
organic chem compound produced by specialized cells
goes into the circulation to inhibit or stimulate a response of another organ or tissue
exocrine gland
gland secretes contents to surface via lumen or duct
endocrine gland
ductless gland secretes content into circulation
autocrine
cellular secretion where cell or tissue realizing the hormone has receptors for same hormone and allows hormone to effect cell that produced it
endocrine
cellular secretion hormone secreted acts on cell/tissue at another location within body
most common
paracrine
cellular secretion where hormone acts on adjacent cells
half life
time it takes for half of hormone to leave body
what are the two types of neural reflexes
- simple neural reflex
- communication = direct along nerve cells/ secretions of neurotransmitters directly to target tissues
- high speed
- transient action
- pinpoint accuracy on target tissue - Neuroendocrine control
- communication = direct along synapse with hypothalamic neurons, secretions of neurohormones into blood instead of on target tisses
- slower
- short acting
- accurate on target tissue with specific receptors
what is the endocrine reflex
endocrine control
- communication = hormones produced by endorcrine glands secreted into circulation
- slowest
- sustained over time
- very accurate
what does the hypothalamus control
production/secretion of releasing hormones
sexual activity
hunger/thirst
emotions
body temp
functions of hypothalamus
primary regulator of repro functions
interaction with pituitary gland to regulate repro and secrete GnRH
(not as important) groups of neurons with similar functions called nuclei
how does the hypothalamus stimulates the surge and tonic center
surge (female only)- stimulated once per cycle
tonic (both female and male)- stimulated constantly
hormones released from hypothalamus
GnRH
Growth hormone Releasing hormone (GHRH)
somatostatin (inhibits growth)
oxytocin produced by paraventricular nuclei
vasopressin produced by supraoptic nuclei
Anterior pituitary (adenohypophysis)
secretes FSH, LH, and prolactin
communicated with hypothalamus through hypothalamo-hypophyseal portal system (sim to panpiniform plexus)
-this allows GnRH to enter directly into AP
Posterior pituitary (neurohypophysis)
composed of neurons that originate in the hypothalamus
axons extend through stalk and terminate in lobe
neurohormones released directly into PP
-oxytocin, vasopressin
what are defining characteristics of repro hormones
- act in minute quantities
- half life influences biological activity (usually short)
- exert a response through binding to certain receptors
- regulate cellular activity
- doesn’t take very much to cause an effect
what affects hormone potency
- half life of hormone
- receptor numbers in cells
- receptor affinity for hormone (ability to hang on to hormone)
what is the…
1. source of hormones
- biochemical composistion
- mode of action
- the site of production
- structure and size
- nuerohormones (oxytocin and vasopressin)
- releasing hormones (GnRH)
- primary hormone of repro (FSH, LH, E2, P4)
- metabolic (insulin, thyroxin, growth hormone)
gonadotropin releasing hormone (GnRH)
Bio Chem Classification: neuropeptide
source: hypothalamic
Male/female target tissue: anterior pituitary (gonadotroph cells)
binding site: membrane
primary function: release FSH and LH from anterior pituitary
Secondary messenger: Calcium
Luteinizing Hormone (LH)
Bio Chem Classification: Glycoprotein
source: anterior pituitary
male target tissue: testis (interstitial cells of Leydig)
female target tissue: ovary (theca interna -luteal cells)
binding site: membrane
functions:
- stimulates testosterone production
- stimulates ovulation, formation of corpus luteum and progesterone secretion
secondary messenger: cAMP
follicle stimulating hormone (FSH)
bio chem class: glycoprotein
source: anterior pituitary
male target tissue: testis (Sertoli cells)
female target tissue: ovary (granulosa cells)
binding site: membrane
Function: Sertoli cell function
follicular development and estradiol synthesis
secondary messenger: cAMP
prolactin (PRL)
bio chem classification: protein
source: anterior pituitary
male target tissue: testis and brain
female target tissue: mammary cells, corpus luteum in some species (rat mouse)
oxytocin (OT)
bio chem class: neuropeptide
source: synthesized in hypothalamus stored and released in posterior pituitary, also synthesized by corpus luteum
male target tissue: smooth muscle of epididymal tail, vas deferens, ampulla
female target tissue: myometrium and endometrium of uterus, myoepithelial cells of mammary gland
binding site: membrane
secondary messenger: calcium
Estradiol (E2)
bio chem class: steroid
source: granulosa cells of follicle, and Sertoli cells of testis
male target tissue: brain (inhibits long bone growth)
female target tissue: hypothalmus, entire repro tract and mammary gland
binding site: nuclear/membrane
function: sexual behavior, GnRH, elevated secretory activity of the entire female tract, enhanced uterine motility
secondary messenger: cAMP if membrane
Progesterone (P4)
bio chem class: steroid
source: corpus luteum and placenta
no male target tissue
female target tissue: uterine endometrium, mammary gland, myometrium, hypothalmus
binding site: membrane/nuclear
Function: none in male
- endometrial secretion, inhibits reproductive behavior, promotes maintenance of pregnancy
secondary messenger: cAMP
testosterone (T)
bio chem class: steroid
source: Leydig cells, theca interna cells of female
male target tissue: accessory sex glands, tunica dartos , seminiferous epithelium, skeletal muscle
female target tissue: brain, skeletal muscle, granulosa cells
binding site: nuclear/membrane
function:
- male: anabolic growth, promotes spermatogenesis, promotes secretion of accessory sex glands
- female: substrate for E2 synthesis, abdnormal masculinization (hair patterns, voice, behavior)
secondary messenger = cAMP if membrane
inhibin
bio chem class: glycoprotein
source: granulosa cells (female), Sertoli cells (male)
male/female target tissue: gonadotrophs of anterior pituitary
prostaglandin F2alpha (PGF2a)
bio chem class: prostaglandin
source: uterine endometrium, vesicular glands
male target tissue: epididymis
female target tissue: corpus luteum, uterine myometrium, ovulatory follicules
binding site: membrane
function:
- male: affects metabolic activity of spermatozoa, causes epididymal contractions
- female: luteolysis, promotes uterine tone and contraction, ovulation
secondary messenger: calcium
