Lecture 01 & 02: Male Repro Anatomy

Functions of the male reproductive system

To produce, store and deliver sperm

Functions of the scrotum

Protection, support, and thermoregulation of the testes

List the 4 layers of the scrotum

* skin: epidermis and dermis
* tunica dartos: thick smooth muscle layer around and between testes
* scrotal fascia: CT
* Parietal vaginal tunic: provides low friction interface between scrotum and testes

In which direction does the tunica dartos move the testes

Horizontally

List the 5 mechanisms for thermoregulation

* sweating
* panting
* pampiniform plexus
* tunica dartos
* cremaster muscle

If surface area is increased for the scrotum, what state are the muscles in

Relaxed

Function of testes

Production of male gametes, hormones, proteins, and fluids

List the 2 layers of the testis

* visceral vaginal tunic: frictionless layer between scrotum and testes
* tunica albuginea: CT layer that holds all of the testis components in place

List the two regions of the testis

* parenchyma
* mediastinum

Structures in the mediastinum

Rete testes/tubules

Function of the rete testis

Transport of sperm

structures in the parenchyma

Seminiferous tubules, Leydig cels

Function of the seminiferous tubules

Production of sperm, hormones, proteins, and fluid. Also contains the Sertoli cells

Function of the Leydig cells

Production of testosterone and Insl-3

Function of Sertoli cells

Helps support primordial sperm cells, production of AMH

Parts of the male excurrent duct system

Epididymis, ductus deferens, spermatic cord, ampulla, urethra

All of the excurrent duct system is surrounded by what

Smooth muscle

Function of the epididymis

Transports sperm from the rete testes, stores sperm for maturation

List the three sections of the epididymis

Caput, corpus, cauda

Where does the ductus deferens begin

At the end of the cauda epididymis

Function of the spermatic cord

Connects the testes and scrotum to the body wall through the inguinal ring, provides passageway, protects testes, thermoregulation

Type of muscle tissue in cremaster muscle

Skeletal muscle

Function of cremaster muscle

Moves testes vertically for protection and thermoregulation

Function of pampiniform plexus

Cools blood as it goes into the testes, heats it back up as it reenters the abdomen

Describe the ampulla

Enlarged area of ductus deferens where the 2 join to form a single tube

What is the single tube formed after fusion at the ampulla

Urethra

Function of urethra

Common duct that carries semen and urine outside of the body

List the 3 possible accessory sex glands

* seminal vesicles
* prostate gland
* bulbourethral glands

Function of accessory sex glands

Production of seminal fluid

Function of seminal fluid

Vehicle for sperm delivery, maintains sperm viability, slight alkaline pH environment

Contents secreted by seminal vesicles

* 50-80% of seminal fluid
* fructose
* semenogelin: coagulation protein

Contents secreted by prostate gland

* Alkaline fluid: responsible for characteristic odor
* Zinc
* Citric Acid
* Proteolytic enzymes

Where is the prostate gland found

Base of the bladder

Which male accessory sex glands are androgen depedant

Prostate gland, bulbourethral glands

Contents secreted by bulbourethral glands

Seminal fluid components, gel plug in rodents and boars

List the 3 parts of the penis

* base/root/bulb
* shaft
* glans

List and describe the different types of erection

* Fibroelastic: erection due to sigmoid flexure and retractor penis muscles, limited erectile tissue. Present in most animals
* Vascular: erection through erectile tissue (hydrostatic skeleton), could still be accomplished through RPM. Present in stallions and primates

What and where are the RPMs

A pair of smooth muscles, attached to lumbar or sacral vertebrae. Holds ducts of a non-erect penis into the sigmoid flexure. During erection, the RPM relaxes

List the layers of a fibroelastic penis, superficial to deep

* tunica albuginea
* corpus cavernosum
* corpus spongiosum
* urethra

Function of corpus spongiosum

To protect the urethra and keep it open during erection