repro test 1 Male Reproductive anatomy

Vocabulary flashcards generated from the chapter notes covering key anatomical terms, physiological structures, thermoregulatory mechanisms, and species variations of the male reproductive tract.

Pampiniform Plexus

A specialized vascular structure in the spermatic cord formed by a single convoluted testicular artery wrapped with branched testicular veins, which functions as a countercurrent heat exchanger to keep the testicles $4\text{ to }6\,^\times\text{C}$ cooler than core body temperature.

Cremaster Muscle

A striated muscle located in the spermatic cord that contracts for short-term movement of the testicles during fight-or-flight situations to prevent injury, but is incapable of long-term contraction for temperature regulation.

Dartos Muscle

A smooth muscle lining the scrotum capable of sustained, long-term contractions; it contracts to pull testicles closer to the body core when cold and relaxes to allow them to sag away when warm.

Thermosensitive Neurons

Temperature-sensing neurons located specifically in the scrotal skin that trigger increased respiration (panting) and sweat gland activation when testicles become too warm.

Cryptorchidism

A condition in which one or both testicles fail to descend from the abdominal cavity into the scrotum.

Bilateral Cryptorchidism

A condition in which both testicles fail to descend into the scrotum, resulting in male sterility due to elevated internal body temperatures.

Unilateral Cryptorchidism

A condition in which only one testicle fails to descend into the scrotum; the male remains fertile due to the single descended testicle.

Gubernaculum

A connective tissue structure attached to the testicle and lower scrotum that first grows and then regresses during fetal development to pull the testicle through the inguinal ring into the scrotum.

Inguinal Ring

An opening in the abdominal wall through which the testicles pass during testicular descent before typically closing.

Mediastinum

A central structural line in the testicular parenchyma containing collecting tubules that transport sperm from the seminiferous tubules toward the efferent ducts and epididymis.

Leydig Cells

Cells located in the interstitial compartment of the testicle responsible for synthesizing testosterone.

Sertoli Cells

Somatic cells located in the adluminal compartment of the seminiferous tubules that physically and metabolically support developing germ cells during spermatogenesis.

Peritubular Myoid Cells

Skinny, muscular cells in the basal compartment of the seminiferous tubules that overlap to form the outer physical boundary of the blood-testes barrier.

Blood-Testes Barrier

A cellular barrier formed by peritubular myoid cells and tight junctions between Sertoli cells that protects post-meiotic, haploid germ cells in the adluminal compartment from immune system attack.

Tight Junctions

Intercellular connections between adjacent Sertoli cells that form an impermeable seal within the blood-testes barrier to block immune cells.

Gel Fraction

A viscous secretion produced by the bulbourethral gland during the final phase of ejaculation (notably in boars) that coagulates in the cervix to form a plug preventing sperm backflow.

Fibroelastic Penis

A penis type composed primarily of dense fibrous connective tissue and a sigmoid flexure (found in bulls, boars, rams, and bucks) that achieves erection by straightening rather than expanding significantly in diameter.

Sigmoid Flexure

An S-shaped bend in a fibroelastic penis maintained by the retractor penis muscle while the penis is flaccid.

Vascular Penis

A penis type lacking a sigmoid flexure (found in stallions and humans) that increases substantially in both length and diameter during erection due to blood engorgement.

Urethral Process

A slender extension of the urethra extending beyond the glans penis in rams and bucks (also termed filiform appendage) that sprays ejaculate near the cervix, but can become blocked by urinary calculi.

Penile Spines

Small, backward-facing mucosal projections on the glans penis of a tomcat that excite sensory neurons in the queen's vagina during copulation to induce ovulation.

Visceral and Parietal vaginal tunic

membranes in the vaginal cavity, which helps the testes move freely

What are the four things involved in thermoregulation

Pampiniform Plexus, Dartos muscle, respiratory center of the brain, and the scrotal skin

How does the thermosensitive neurons in the scrotum work?

They activate when it gets hot, causing the male to start panting, which releases hot air allowing the testicles to cool

What happens if the inguinal ring does not close?

It can lead to an inguinal hernia, allowing fat and intestines to protrude into the inguinal canal.

What’s in the deep adluminal compartment?

Sertoli cells, gametes (germ cells), and sperm (male gamete)

Whats in the basal compartment (blood testes barrier)

Peritubular myoid cells and tight junctions

What’s in the interstitial compartment?

Leydig cells, blood vessels, and lymphatic channels.

Is the head of the epididymis capable of fertilization?

no

Where does the fibroelastic penis ejaculate?

In the vagina

Where does the vascular penis ejaculate?

In the cervix