Male Repro 2 Flashcards
What is the difference between between a musculovascular and fibroelastic penises?
musculovascular penises enlarge in length and diamater during tumescene whereas fibroelastic penises are sigmoidal shaped that extend only in length during tumescence
What is the urethral process?
an extension of the urethra that extends beyond the length of the penis in the ram and the buck
What is the function of the urethral process?
it is possibly a mechanism to propel sperm deeper into the female reproductive tract
Why can the urethral process be problematic?
because it can get stones trapped in it
What is corpus cavernosum?
erectile tissue of the penis
What is the corpus spongiosum?
spongy area that surrounds the urethra and prevents occlusion of the urethra during tumescence
What is nitric oxides role in tumescence?
it causes dilation of the helicine artery which allows blood to move through the loosened interendothelial junctions
What is nitric oxide released from in tumescence?
it is released by non-adrenergic/non-cholinergic neurons from the parasympathetic system
What biochemical basis allows for detumescence to occur?
phosphodiesterase 5 recycles cGMP to GMP thus halting tumescence by returning the vascular smooth muscle to its contracted state
What is the vascular basis of detumescence?
once the vascular smooth muscle ccontracts, blood from the helicine artery leaves the corpus cavernosum and the penis drains
What autonomic system is tumescence driven by and how does it work?
the parasympathetic division involving the release of norepinephrine that relaxes the vascular smooth muscle of the helicine artery in the penis
What autonomic system is ejaculation driven by and how does it work?
the sympathetic system that promotes the release of mucus and the coordinated contraction of the epididymis, vas deferens, and urethra
What autonomic system is demutescence run by?
the sympathetic system
What hypothalamic peptide is the central regulator of male reproductive physiology?
GnRH
What are the two anterior pituitary hormones that regulate male reproductive physiology?
LH and FSH
What is the function of LH in male reproductive physiology?
it synthesizes testosterone in the leydig cells
What is the function of FSH in male reproductive physiology?
it stimulates spermatogenesis in the sertoli cells by promoting the elevation of the spermatocytes towards the lumen of the seminiferous tubules
What is the negative regulator of the male reproductive physiologic hormones?
inhibin
What is the role of inhibin in male reproductive physiology?
it activates its receptor and promotes the synthesis of proteins that trap FSH in the anterior pituitary cells or GnRH in the hypothalamus
What does inhibin come from?
sertoli cells
Why does testosterone interact with an intracellular receptor while other hormones interact with receptors that extend outside of the cell?
because testosterone is lipid-soluble so it can cross biological membranes and interact with its intracellular receptor
What is the os penis?
a bone in the penis in the dog, cat, and non-human primates that aid in maintaining tumescence
What is the bulbus glandis?
a portion of the penis in the dog that enlarges during coitus which helps maintain the ineraction with the female
Why is cancer a side effect of anabolic steroids that mimic testosterone?
because it upregulates specific gene expression in genes that encode for proteins that promote hyperplasia
