UNIT 5 A&P LECTURE

What are the 3 functions for the reproductive system?

1. Produce gametes, 2. Stores, nourishes, and transports gametes, 3. Produce sex hormones

How are gametes produced?

meiosis!

What are gametes?

Sex cells

What do the testes do?

Produce gametes & hormones

What do ducts in the Male reproductive system do?

Transport, storage, and maturation of gametes.

What are the different types of ducts in the Male reproductive system?

Epididymis, ductus (vas) deferens, ejaculatory ducts, urethra

What do accessory sex glands do in male reproductive system?

Contribute to seminal fluid

What are the 3 types of sex glands in the male reproductive system?

Seminal vesicles, prostate gland, bulbourethral (Cowper’s) glands

What are the supporting structures

scrotum and penis

What hormones does the testes secrete

Androgens( testosterone and dihydrotestosterone (DHT)), inhibin, and androgen-binding protein (ABP)

What are the testes supported by?

The scrotum

Are male gametes continou being producted?

Yes

Where in the testes produce sperm?

Seminiferous tubules produce sperm by spermatogenesis

What is the scrotum made of?

Loose skin, subcutaneous layer and muscle

What seprates the two testes?

Two testes separated by scrotal septum

What is the dartos muscle?

Part of the Scrotum, It's just under the skin and surrounds both testes.

How many cremaster muscles part are there?

one for each testis

What do muscles help do help regulate the testes?

They help to reulgate the tempaure of the testes, 2-3° C below body temp.

What temperature is required for Spermatogenesis?

requires temperature 2-3°C below body temperature

What stucutres help maintain temperature of the testes?

Scrotum, Cremaster muscle & dartos muscle, and Pampiniform plexus

How extactly does the Cremaster muscle & dartos muscle help control the termpure of the testes?

They contract to elevate which increases testicular temperature. They can relax to lower testes which decreases testicular temperature

What is the Pampiniform plexus?

A Highly branched network of the testicular veins

How does the Pampiniform plexus regulatetesticular temperature?

The large surface area helps with efficicent heat exchange. The countercurrest heat exchanges helps cool the blood in the testicular arterys

What are the 2 types of cells in the seminiferous tubules?

spermatogenic cells and Sertoli cells (sustentacular cells)

What are Sertoli cells (sustentacular cells)?

Somatic cells that constitute the main structural component of seminiferous tubules in testes, where germ cells reside

What are spermatogenic cells?

Germs cells that mature into spermatozoa (sperm) through the process of spermatogenesis

What are the functions of Sertoli cells?

nourish developing sperm, phagocytize excess spermatid cytoplasm, release sperm into lumen, secrete hormones (inhibin and ABP), and make the blood-testis barrier.

What make up the blood-testis barrier and what does it do?

It's made of Sertoli cells and it prevents immune system from recognizing sperm as foreign.

What does Sertoli cells phagocytize?

excess spermatid cytoplasm.

What hormones do Sertoli cells secrete?

Inhibin and ABP.

What cells in the testes secrete what hormones?

Sertoli cells secrete inhibin and ABP. Leydig cells secrete androgens (testosterone, DHT)

What is Spermatogenesis?

the biological process of creating mature male sperm cells (spermatozoa) within the testes

Where does spermatogensis begin?

begins in spermatogonia (2n)

What is a spermatogonia?

It's a stem cell. When dividing some stay as spermatogoniao for future division.

What cell does a spermatgonia?

A primary spermatocyte (2n)

What do primary spermatocyte (2n) do?

they repilate their dna and meiosis begins.

What cell comes after primary spermatocyte once meiosis 1 is complete?

2 secondary spermatocytes (1n) are formed after meiosis I

What is then formed after meiosis 2?

4 spermatids (1n)

What are secondary spermatocytes and spermatids are attached by?

the cytoplasmic bridge

What does the cytoplasmic bridge do?

It helps sperm development be synchronized.

What is spermiogenesis?

spermatids develop into sperm

What is spermiation?

sperm released and enter lumen of seminiferous tubule

What is the difference between spermiogenesis and Spermatogenesis?

Spermatogenesis is the first part, it's the process of spermatogonia undergoing mitosis and primary spermatocyte becoming spermatids via meiosis. spermiogenesis is spermatids becoming sperm and being released into the seminiferous tubules

Draw and describe both Spermatogenesis and spermiogenesis

What is acrosome?

At the front of the sperm cell and has enzymes to help penetrate secondary oocyte.

Whats the nucleus like in a sperm cell?

pro-nucleus (1n)

Whats in the middle peice of a sperm cell?

mitochondria in spiral form.

What is the Epididymis in the Male Reproductive System?

It's the site for sperm maturation, and it helps proepl sperm into vas defernens

Where is the epididymis located?

Posterior border of the testes.

What do sperm cells acrrure in the epiddiymis to become mature?

acquire motility and ability to fertilize ovum

When is the spermatic cord formed?

formed during the descent of the testes

What is the path of the spermatic cord?

ascends out of scrotum, passes through inguinal canal

What does the spermatic cord include?

Ductus (vas) deferens, Testicular artery, Pampiniform plexus, Cremaster muscle, Nerves, Lymphatics.

What duct takes sperm from the epididymis to the urethra?

Vas deferens.

Can sperm be stored in the Vas deferens?

Yes

What happens to non ejaculated sperm in the Vas deferens?

sperm not ejaculated is reabsorbed

Where is the Ejaculatory ducts?

where the vas deferens and seminal vesicle meet.

Ejaculatory ducts do?

eject sperm + seminal vesicle secretions

What is the urethra?

A shared duct of reproductive and urinary systems

Where are the Seminal vesicles?

posterior to bladder, theres 2.

Is the fluid from the seminal vesicles acidic or alkaline?

alkaline to neutralize acidic environment of male urethra and female reproductive tract.

What does secretions of the Seminal vesicles contain?

fructose (for atp production) and clotting proteins ( coagulation)

What makes up most of semen

Fluid from the seminal vesicles

Where is the prostate

inferior to bladder and surrounds urethra.

Is the fluid from the prostate acidic or alkaline?

slightly acidic and has a milky coloring

Does the prostate secrete?

citric acid (ATP production), proteolytic enzymes (break down clotting proteins), seminalplasmin (antibiotic).

Where is the Bulbourethral glands ?

It's inferior to the prostate

Is the fluid from the Bulbourethral glands acidic or alkaline?

alkaline fluid to neutralize acidity of urethra

What does the Bulbourethral glands secrete?

secretes mucus for lubrication of urethra (decreases damage to sperm.

Compare and Contrast the secretions of each gland within the male reproductive system

Bulbourethral glands - mucus (lubrication) ,

Prostate - citric acid (ATP production), proteolytic enzymes (break down clotting proteins), seminalplasmin (antibiotic),

Seminal vesicles - fructose (atp production) and clotting proteins

Label this photo

1 - vas defernes
2- seminal vesicle
3- ejaculatory duct
4- bulbourethral glands (cowper’s)
5- prostate!

What is semen?

sperm + seminal fluid

Is sperm acidic or alkaline?

slightly alkaline

Desbribe the coagulation process of semen

within 5 minutes semen coagulate but after 10-20 minutes it re-liquifes.

What are the 3 cylindrical masses of erectile tissue in the penis?

corpora cavernosa (2 of them) and corpora spongiosum

What is the tunica albuginea in male reproductive system?

onnective tissue that surrounds erectile tissue.

What is the corpora cavernosa?

It's where most of the blood going during erection.

What is the corpora spongiosum?

contains spongy or penile urethra

What is the purpose of the corpora spongiosum?

to keep the urethra open during ejaculation

What is the glans penis?

It's the distal end of the spongiosum.

What nervous system from sexual stimulation causes eretion?

parasympathetic

What does parasympathetic produce to cause erection?

They produce and relase NO and compress veins to slow outflow.

What does NO do in the male reproductive system?

NO causes smooth muscles in arterioles of erectile tissue to dilate and NO also causes smooth muscle in erectile tissue to relax (widening of spaces)

What is ejaculation?

a powerful release of semen. What kind of a reflex is ejaculation?

What happens relating to the bladder during ejaculation

smooth muscle sphincter at base of bladder closes. It prevents urine output or semen entering the bladder.

What happens after ejaculation?

when stimulation has ended, arterioles constrict and relieves pressure on the veins.

What secretion from the hypothalamus increases during pubery?

gonadotropin-releasing hormone (GnRH)

What does luteinizing hormone (LH) and follicle stimulating hormone (FSH) come from?

anterior pituitary

What cells do luteinizing hormone (LH) stimulate?

Leydig cells

What do Leydig cells secrete?

secretes androgens (testosterone, DHT)

What cells does FSH act on?

Sertoli cells

What does Sertoli cells secrete?

inhibin and androgen-binding protein (ABP)

What does androgen-binding protein (ABP) do?

binds to testosterone to keep concentration high (testosterone is needed for final steps of spermatogenesis)

What does inhinin do?

inhibits FSH secretion by anterior pituitary

What does Testosterone do during prenatal development?

reproductive system ducts and testes

What does DHT do during prenatal development?

external genitals

How does testosterone help in pre natal brain development?

testosterone is converted into estrogens in the brain (development of certain brain regions)

What does testosterone do to organs?

development and enlargement of organs

What are secondary sex characteristics of a male?

wide shoulders, narrow hips, facial and chest hair,thickening of skin, increased sebaceous glands, enlargement of larynx.