Unit 2 - Chpts. 23, 26, 22, 8 Flashcards
Where does synthesis of thyroid hormones occur?
Thyroid follicles
In Graves’ disease, antibodies bind to TSH receptors leading to
increased T3/T4 and decreased TSH and TRH
Primary hypothyroidism caused by a lack of iodine in the diet leads to
decreased T3/T4 and increased TSH and TRH
Patients with hyperthyroidism experience heat intolerance. What mechanism would explain this?
The production of ATP is increased resulting ni more exothermic reactions taking place
In a hypophysectomized rat, which of the following would you expect to find?
Decreased levels of T3 and T4
What hormone “turns off” Growth Hormone?
Somatostatin
What digestive system hormone sends a signal to the hypothalamus to produce GHRH?
Ghrelin
What does GH indirectly impact?
The liver which produces Insulin-like growth factors, leading to cartilage growth
What are some stimulatory factors for GH release?
Sleep
Stress (only a little)
Exercise
Hormones of puberty
What are some inhibitory factors for GH release?
Obesity
Senescence
Somatostatin
GH (negative feedback)
Increased IGF (negative feedback)
Increased glucose
Increased fatty acids
What are the actions of GH?
Increase lipolysis and gluconeogenesis, decrease glucose uptake by muscle –> increases blood glucose
Which of the following statements about growth hormone is incorrect?
a) Cortisol released in response to stress inhibits the release of GH
b) Hypersecretion of GH in children causes gigantism
c) Hyposecretion of GH in children can be treated with bovine GH
d) Hypersecretion of GH in adults causes acromelaly
c) Hyposecretion of GH in children can be treated with bovine GH
GH is species specific
True or False: Thyroid hormones play a permissive role in tissue and bone growth
True
What stimulates protein synthesis and provides energy?
Insulin (glucose)
Role of osteoblast
produce enzymes and osteoid (build bone)
Role of osteoclast
secrete acid that dissolves calcified matrix (catabolize bone)
What is the most common form of calcium phosphate?
Hydroxyapatite
Role of parathyroid hormone
1) Mobilizes calcium from bone
2) enchances renal reabsorption of calcium
3) indirectly increases intestinal absorption of Ca2+
Signs of hypo calcium?
Muscle cramps
Convulsions and seizures
Tingling and numbness
Hyperactive bowels
Brittle hair/nails
Signs of hyper calcium
Muscle weakness
Constipation
Hypertension
Polydipsia
Polyuria
Lethargy, coma
Increased levels of phosphate ions in the boddy would likely accompany ____?
Bone loss during osteoporosis
Concerning calcium homeostasis, what is the correct relationship?
Osteoblasts build bone, osteoclasts catalyze its reabsorption
3 sets of sex organ structures?
1 - internal
2 - external
3 - gonads (ovaries and testes)
What are bipotential gonads?
gonad that could develop into either the ovaries or testes depending on presence of SRY gene
Which ducts belong to the male system?
Wolffian ducts (mullerian duct regresses)
Which ducts belong to the female system?
Mullerian ducts (wolffian duct regresses)
What hormone causes the Mullerian duct to disappear?
Anti-Mullerian hormone (produced by testes)
What causes the Wolffian ducts to disappear?
Absence of anti-mullerian hormone
What structures arise from the Mullerian duct in the female system?
Fallopian tube
Uterus
Upper part of vagina
What structures arise from the Wolffian duct in the male system?
Seminal vesical
Vas deferens
Epididymis
What do the genital tubercle, uretheral folds and grooves, and labioscrotal swellings form in the female system?
Genital - Clitoris
Uretheral - Labia minora, opening of vagina and urethra
Labioscrotal - labia majora
What do the genital tubercle, uretheral folds and grooves, and labioscrotal swellings form in the male system?
Genital - Glans penis
Uretheral - Shaft of penis
Labioscrotal - Shaft of penis and scrotum
What do interstitial cells secrete?
Testosterone
What do sertoli cells secrete?
anti-mullerian hormone
Pathway for GnRH in males
1) GnRH –> LH –> interstital cells of leydig –> testosterone
2) GnRH –> FSH –> sertoli cells (sastenacula) –> anti-mullerian hormone, sperm
Stem cell for sperm
Spermatogonia
Stem cell for eggs
Oogonium
Sex determination during development depends on the presence of
SRY gene
Testosterone is required for testicular development
False
Which is true for an individual with Turner’s Syndrome (X0)?
Embryo develops in a female, female reproduction function is impaired
How does the amount of DNA in the first polar body compare to that in the second polar body?
2x as much
What organ stores sperm?
Epididymis
What accessory glands contribute to secretions to semen?
Prostate gland and Bulbourethral gland
What is the role of the sertoli cell in spermiogenesis
secrete proteins to support
What type of junctions are present in the lumen of the seminiferous tubule and what role do they play?
Gap junctions between sertoli cells to provide developing sperm with nutrients
Role of blood testis barrier?
Keeps immune cells out
What is a spermatid?
a haploid cell that is not yet a sperm, develop into spermatozoa
What is the acrosome?
Allows sperm to get to egg by erroding part part of cell wall
Role of mitochondrial spiral in sperm?
help provide energy for flagella to move
Why does semen need buffers?
to neutralize acidic environment of vagina
What is unique about the production of GnRH?
It is pulsitile
What is Androgen-binding protein and what role does it have?
Produced by sertoli cells, keeps testosterone cells at a steady state, can bind to excess testosterone to keep it in the seminiferous tubules
Pathway of erection
Testosterone –> sexual arousal –> increase in parasympathetic signaling to penis –> increased nitric oxide release –> arterial and trabecular smooth muscle relaxation –> arterial dilation –> increased arterial blood flow and pressure & decreased blood flow out –> increased intracevernosal pressure –> increased penile rigidity –> erection
What are the 3 erection tissues?
Corpora cavernosa
Cavernosal artery
Corpus spongiosum
Developing spermatozoa are nourished by
sertoli cells (aka nurse cells)
In the erection reflex, stimulation of parasympathetic neurons causes vasodilation so erectile tissues in the penis shaft receive increased blood flow
True
After leaving the seminiferous tubule, spermatozoa enter the ___
epididymis
Pathway of spermatozoa
Seminiferous tubule –> epididymis –> vas deferens –> urethra
Why do anabolic steroids cause testes to shrink, making males temporarily infertile?
FSH secretion decreases
In males, what is the main target for FSH?
Sertoli cells
What does LH stimulate in males?
testosterone production
What are the 2 layers of the endometrium?
Basal layer (stem)
Functional layer (thicken)
What type of tissue is the myometrium made of?
smooth muscle
Where do cramps come from?
Cramps are the result of the myometrium contracting and pinching off the spiral ateries (the functional layer of the endometrium)
What are Granuloso cells?
make the enzyme aromatase, converts androgens to estrogen and inhibin (estrogen inhibits FSH and GnRH, inhibin inhibits FSH)
Pathway of an egg
Primordial follicles –> primary follicle –> secondary follicle –> early tertiary follicle –> dominant follicle w/oocyte –> ovulated oocyte –> Corpus luteum –> regressing corpus luteum
What pathway does LH use to make estrogen?
Secondary messengers (cAMP)