BIOL 1051H Study Guide - Final Guide: Corpus Luteum, Follicle-Stimulating Hormone, Seminiferous Tubule
Exam Review
Reproduction
Endocrine Control of Puberty
●Follicle Stimulating Hormone (FSH)
○Stimulates sustentacular cells to secrete androgen-binding protein that binds
testosterone, keeping it in seminiferous tubule lumen to stimulate spermatogenesis
●Luteinizing Hormone (LH)
○Stimulates interstitial cells in testes to produce testosterone
Spermatogenesis
●Type B spermatogonia becomes a primary spermatocyte
●Primary spermatocyte undergoes meiosis 1 which gives rise of two secondary
spermatocytes.
●Each secondary spermatocyte undergoes meiosis 2 dividing into two spermatids
●Spermiogenesis: discard excess cytoplasm and grow a tail- mature spermatozoa
●Spermatogenesis: process of sperm production in seminiferous tubules of testes
Stages of Puberty in Women
●Thelarche
○Onset of breast development, the earliest noticeable sign of puberty
●Pubarche
○Appearance of pubicn and axillary hair, sebaceous glands, and axillary glands.
●Menarche
○First menstrual period
○Dependent on body fat ( at least 17%)
Prenatal Development
●Conceptus: All products of conception: the embryo or fetus, the placenta, and associated
membranes
●Blastocyst: the developing individual is a hollow ball for the first weeks
●Embryo: day 16- week 8
●Fetus: week 9- birth
●Neonate: newborn-6 weeks
Human Chorionic Gonadotropin (hCG)
●Secreted by blastocyst and placenta
●Detectable in urine 8-9 days after conception
●Stimulates growth of corpus luteum
○Corpus luteum secretes increasing amounts of progesterone and estrogen
●Essential for maintenance of corpus luteum
Lactation
●All female mammals have mammary glands
●Lactation is production and ejection of milk
●Two functional steps:
○Milk Production
○Ejection or let-down
●All mammary glands have same basic structure
Lactation Controlled by:
●Prolactin
○Milk production and secretion
○Sucking is essential
○In hypothalamus, reduction in dopamine (PIH) and increase in PRH
○Amount of prolactin depends on degree of stimulation
●Oxytocin
○Milk ejection reflex
○Activated by suckling
○Oxytocin neurons in hypothalamus activated
○Oxytocin secreted into blood stream, causes contraction
Conditional Hormones Secretion
●Most potent stimulus for MER is suckling
●Baby’s cry or rattle of milk bucket
●Conditional secretion does not occur for prolactin
Fluid, Electrolyte and Acid-Base Balance
The great percentage of the body’s water is in
●The intracellular fluid
Regulation of Fluid Intake
●Governed mainly by thirst
●Osmoreceptors respond to Angll and rise osmolarity of ECF
Renin- Angiotensin- Aldosterone (RAAS) System
●A system of hormones that helps control BP and filtration in the kidneys
●Angiotensin
○Potent vasoconstrictor raising BP
○Constricts efferent arteriole raising kidney filtration
○Stimulates adrenal cortex to secrete aldosterone, which promotes Na and H2O
reabsorption
○Stimulates posterior pituitary to secrete ADH which promotes H2O reabsorption
○Stimulates thirst
Aldosterone - the “salt-retaining hormone”
●Steroid hormone secreted by the adrenal cortex
●Functions of aldosterone
○Acts on thick segment of nephron loop, DCT, and cortical portion of collecting
duct
■Stimulates reabsorption of Na and secretion of K
Fluid Deficiency
●Volume Depletion (hypovolemia)
○Proportionate loss of water and sodium without replacement
○Osmolarity remains normal
●Dehydration (negative water balance)
○Body eliminates more water than sodium
○Osmolarity of ECF rises
Sodium Balance
●One of principal ions responsible for resting membrane potential
○Na inflow essential to depolarization that underlies nerve and muscle function
●Principal cation of ECF
●Most significant solute in determining total body water and distribution
Sodium Balance
●Aldosterone
○Main hormone that regulates sodium
Document Summary
Stimulates sustentacular cells to secrete androgen-binding protein that binds testosterone, keeping it in seminiferous tubule lumen to stimulate spermatogenesis. Stimulates interstitial cells in testes to produce testosterone. Type b spermatogonia becomes a primary spermatocyte. Primary spermatocyte undergoes meiosis 1 which gives rise of two secondary spermatocytes. Each secondary spermatocyte undergoes meiosis 2 dividing into two spermatids. Spermiogenesis: discard excess cytoplasm and grow a tail- mature spermatozoa. Spermatogenesis : process of sperm production in seminiferous tubules of testes. Onset of breast development, the earliest noticeable sign of puberty. Appearance of pubicn and axillary hair, sebaceous glands, and axillary glands. Dependent on body fat ( at least 17%) Conceptus : all products of conception: the embryo or fetus, the placenta, and associated membranes. Blastocyst: the developing individual is a hollow ball for the first weeks. Detectable in urine 8-9 days after conception. Corpus luteum secretes increasing amounts of progesterone and estrogen. Lactation is production and ejection of milk.
