Reproductive Hormonal Function Males Lecture

Internal Structures

Internal or External? Seminiferous tubules, epididymis, vas deferens, seminal vesicles, prostate gland, bulbourethral gland

External Structures

Internal or External? Scrotum, testes, erectile tissues, prepuce, glans penis

Testes

Site of spermatogenesis and testosterone production

Sertoli Cells

What cells function to serve as the site for spermatogenesis, the process of sperm production

Leydig Cells

What cells are responsible for testosterone production in the testes.

Seminiferous tubules

Each testis contains 900 ______ each 1 m in length

Epididymis

Coiled tube 6m in length, store and mature sperm

Vas deferens

Tube that transports mature sperm to the urethra

Tunica Albuginea

Dense white connective tissue surrounding the testes and keeping them compact.

Spermatocele (hydrocele)

A fluid-filled sac that develops in the epididymis, often containing sperm. It is usually painless and can vary in size. Results from numerous causes including infection or impact trauma and does not affect fertility.

Testicular cancer

1 in 250 to 5000 men develop _____. 95% survival rateif detected early. It typically presents with a painless lump in the testicle.

Seminal Vesicles

Stores mature sperm and produces seminal fluid that makes sperm active

Prostate gland

Produces alkaline seminal fluid that nourishes and surrounds sperm

It neutralizes the acidity of vaginal secretions, providing a suitable environment for sperm motility

Why do we need the alkaline fluid of the prostate gland?

Bulbourethral gland

Produces a fluid (buffer) that leaves the urethra prior to ejaculation, which neutralizes acidic residue in the urethra left behind by urine and provides lubrication during intercourse.

Scrotum

Sack-like structures that protects and regulates temperature of the testes

Cremaster Muscle

Striated muscle (involuntary and voluntary). Functions to raise and lowers testicles to optimize temperature

Dartos Muscle

Smooth muscle (involuntary). Functions to expand (relax) or contract the scrotum. Sympathetic control part of flight or fight response

Cavernosal arteries

Arteries that supply blood to the erectile tissues of the penis, aiding in erection.

Corpus cavernosia

Two cylindrical erectile tissues in the penis that fill with blood during arousal, contributing to an erection. Collect 90% of blood that causes erection (lined smooth muscle).

Corpus spongiosum

A single cylindrical erectile tissue surrounding the urethra, it prevents the urethra from being compressed during erection and allows for ejaculation. Receives 10% of blood that causes the erection (lined smooth muscles)

Prepuce (foreskin)

Protects the glans penis (head) from infection as an infant and abrasion as an adult

Glans Penis (head)

Urethra exits the penis. Contains 400 nerve endings

Circumcision

Removal of the foreskin from the penis, which can reduce the risk of certain infections and improve hygiene.

Arousal, erection, lubrication, coitus, emission, ejaculation

What are the 6 stages of intercourse?

Arousal

Results from a combination of psychic (mental) and physical stimulation

Penile Erection

Degree of erection is infinite stimulation and parasympathetic stimulation of release of nitric oxide, which activates a cascade of neurotransmitters that relax the cavranosal arteries, corpus cavernosa, and corpus spongiosum

Lubrication

Comes from bulbourethral glands and functions to lubricate the urethra (there’s no sperm in this)

Coitus

When intensity reaches a set-point stimulation, reflex centers in the spinal cord (T10 to L3) emit sympathetic impulses that initiate emission and ejaculation

Emission

Contraction of the vas deferens causes expulsion of sperm into the internal urethra, followed by contractions of the prostate and seminal vesicles to release fluids

Semen

Sperm + Prostate Fluid + Seminal Vesicle Fluid =

Ejaculation

Increased fluid pressure in the internal urethra stimulates rhythmic contractions of the ishiocaverenous and bulbocaverenous (skeletal) muscle result in ____ of semen

Orgasm

Emission + Ejaculation =

Refractory and resolution

Follows an erection ceases and the body returns to its resting state before being able to achieve another erection.

Level of excitement, Sexual health, physical health

Factors affecting refractory period

Erectile Dysfunction

The inability to achieve or maintain an erection sufficient for satisfactory sexual performance, often linked to medical or psychological issues. 52% of men experience this at some point in life and 15% of men between 40 and 70 have this

Increases the availability of Nitric Oxide and relax smooth muscle

How does viagra work?

Peroni’s Disease

Curved penis. Caused by a build up of fibrous plaque (scar tissue) in the tunica albuginea. Often results from rough intercourse or sports (impact) injuries and has a variety of treatments including: pharmaceutical, braces, surgical

Tunica albuginea

A sheath of connective tissue surrounding the corpora cavernosa