Reproduction 5052: Male Reproductive Functional Anatomy

These flashcards cover the anatomical components, cellular functions, thermoregulatory mechanisms, and endocrine pathways of the male reproductive system as described in the lecture notes.

High Speed Manufacturing

The functional phase of the male reproductive system occurring in the testis, producing 1-25x10^9 spermatozoa/day (35,000-200,000 per second).

Finishing Shops (2)

The phase involving the head and body of the epididymis where fluid absorption, membrane changes, nuclear/flagellar stabilization, and motility development occur.

Warehouse and Shipping

The function of the tail of the epididymis, storing 10-50x 10^9 spermatozoa, sufficient for 5 to 10 ejaculations.

Final Alterations and Packaging

The function of the accessory sex glands, which provide metabolic substrates, surface coatings, and transport for spermatozoa.

Gubernaculum

A ligamentous structure that undergoes rapid growth followed by regression to pull the testis from a retroperitoneal position into the scrotum.

Insulin like-3 (Insl-3)

A member of the insulin super family synthesized by islet cells and Leydig cells that causes growth of the gubernaculum and testicular descent.

Visceral vaginal tunic

The inner layer of the peritoneum that covers the testis, epididymis, and spermatic cord.

Parietal vaginal tunic

The outer layer of the peritoneum that forms a continuous fold directly adjacent to, but not attached to, the visceral vaginal tunic.

Pampiniform plexus

A network of veins in the spermatic cord that acts as a countercurrent heat exchanger, cooling arterial blood from 39 degrees C to 33 degrees C before it reaches the testis.

Pulse pressure eliminator

A function of the long convoluted testicular artery where pulse pressure is almost eliminated between the inguinal ring and the surface of the testis.

Cremaster muscle

Striated muscle continuous with the internal abdominal oblique that facilitates blood flow in the pampiniform plexus via a "pumping action" but is not capable of sustained contractions.

Tunica dartos

A smooth muscle in the scrotum capable of sustained contractions to elevate the testes close to the body wall; its development is under androgen control.

Blood-testis barrier

Physical barrier formed by peritubular/myoid cells and Sertoli cell tight junctional complexes that excludes immune cells and immunoglobulins from the adluminal compartment.

Androgen binding protein (ABP)

A testosterone transport protein secreted by Sertoli cells that maintains high intratesticular concentrations of testosterone.

Sulfated glycoproteins (SGP) 1 and 2

Substances produced by Sertoli cells related to fertility acquisition (SGP-1) and providing a detergent effect to move cells through the tubular network (SGP-2).

Inhibin

A hormone secreted by Sertoli cells that exerts negative feedback on the anterior lobe of the pituitary to directly suppress FSH secretion.

GnRH Pulsatility

Short-lived bursts of GnRH from the hypothalamus lasting a few minutes that occur frequently throughout the day and night to trigger LH discharges.

alpha-Reductase

The enzyme responsible for converting testosterone ($T$) into dihydrotestosterone ($DHT$) within Sertoli cells and external target tissues.

Leydig cells

Interstitial cells of the testes that contain receptors for LH and secrete testosterone.

Sertoli cells

Cells within the seminiferous tubules that contain receptors for both FSH and testosterone, supporting spermatogenesis.

Sigmoid Flexure

The S-shaped curve in the penis of species like the bull, which allows for protrusion and retraction via the retractor penis muscle.

Polypnea

Panting or rapid breathing (often exceeding 200 cycles per minute) triggered by thermosensitive neurons in the scrotum when temperatures reach 40 degrees C.