Repro 5: Male Reproductive System

Testes, ducts

Basic components of the male reproductive system

Spermatogenesis

Production of sperm by the testes

Testes

Primary reproductive organ

Testicular capsule, parenchyma, rete tubules

Parts of the testes

Testicular capsule

• Made of connective tissue and smooth muscle fibers

• Facilitates movement of spermatozoa into rete tubules and efferent ducts

Seminiferous tubules, interstitial tissue

Parts within parenchyma of testes

Sertoli cells, germ cells

Types of cells within seminiferous tubules of parenchyma

Leydig cells, capillaries, lymphatic vessels

Types of cells and vasculature within interstitial tissue of parenchyma

Seminiferous tubules

Where does spermatogenesis occur?

Sertoli cells

• Blood-testis barrier

• Produce a variety of substances (ABP, transferrin)

Leydig cells

Produce testosterone

Proliferation phase, meiotic phase, differentiation phase

Phases of spermatogenesis

Spermatogonium, primary spermatocyte, secondary spermatocyte, spermatid, spermatozoa

List order of structures during spermatogenesis

Spermiogenesis

Process by which spermatids are transformed into mature spermatozoa that are capable of motility and fertilization

Golgi phase, cap phase, acrosome phase, maturation phase

Phases of spermiogenesis

Rete tubules

Tiny channels through which spermatozoa are transported out of the testis

Efferent ducts, epididymis

Parts of excurrent duct system

Efferent ducts

Convey newly formed spermatozoa and tubular fluid into the epididymal duct

Epididymis

Provides the environment for final maturation of spermatozoa; serves as a storage reservoir for spermatozoa

Epididymal duct

Single highly convoluted duct

Head (caput), body (corpus), tail (cauda)

Regions of epididymis

Inhibin secretion by Sertoli cells

Why is FSH released a lower amount than LH?

FSH has a longer half-life

Why does FSH secretion have a greater duration than LH secretion?

Inhibin, FSH

The Sertoli cells produce ___ that exerts a negative feedback on the anterior lobe of the pituitary to suppress ___.

DHT, estrogen (E2)

Testosterone produced by the Leydig cells is transported into the Sertoli cells, where it is converted to ___ and ___.

C

What is the key event that occurs during spermiogenesis?

A) DNA replication

B) Formation of haploid cells

C) Morphological transformation of spermatids into spermatozoa

D) Crossing over of genetic material

D

The testes of a stallion secrete:

A) Progesterone

B) Estrogen

C) Testosterone

D) Both B and C

C

Which organelle in the sperm head contains enzymes that are important for fertilization?

A) Nucleus

B) Mitochondria

C) Acrosome

D) Golgi apparatus

D

Which structure is responsible for transporting sperm from the seminiferous tubules to the epididymis after spermiogenesis?

A) Vas deferens

B) Epididymal duct

C) Sertoli cells

D) Rete testis

C

What is the final product of spermiogenesis?
A) Spermatogonium

B) Spermatid

C) Spermatozoon (sperm)

D) Spermatocyte

A

The acrosome, formed during spermiogenesis, originates from which cellular organelle?

A) Golgi apparatus

B) Mitochondria

C) Endoplasmic reticulum

D) Lysosomes

C

Which part of the sperm is responsible for motility?

A) Acrosome

B) Midpiece

C) Tail (flagellum)

D) Head

C

What is the role of the acrosome in sperm cells?
A) It stores sperm during ejaculation.

B) It produces seminal fluid.

C) It contains enzymes necessary for fertilizing the egg.

D) It provides energy to the sperm during motility.

A

During spermiogenesis, what major change occurs in the spermatid?

A) The development of the acrosome and tail formation

B) The fusion of the sperm nucleus with the egg nucleus

C) The separation of the sperm head and tail
D) The production of testosterone

B

What is spermiogenesis?

A) The process of sperm production from germ cells.

B) The transformation of spermatids into mature spermatozoa.

C) The transport of sperm from the epididymis

D) The production of seminal fluid by accessory glands