Lecture 20 Flashcards
Functions of Gonads =
Functions of Gonads = produce gametes and secrete sex hormone
What are the 4 functions of the male genital system?
Functions of the male genital system
1) Testes produce sperm an testosterone
2) The ducts transport, store, and assist in maturation of sperm
3) The accessory genital glands secrete most of the liquid of sperm
4) The penis contains the urethra, a passageway for ejaculation of semen and excretion of urine
What divides the scrotum into 2 sections?
The scrotal septum
What is the scrotal septum comprised of?
The scrotal septum is made of:
- Subcutaneous tissue
- Dartos muscle
Where is the cremaster muscle located?
deep in the scrotal wall
Which scrotal muscles is skeletal
cremaster muscle
Dartos Muscle
Type:
Location:
Function:
Dartos Muscle
Type: smooth
Location: in the skin of the scrotum
Function: tonic contraction gives the scrotum its wrinkled apperance
Cremaster Muscle
Type:
Location:
Function:
Cremaster Muscle
Type: skeletal
Location: deep in the scrotal wall
Function: controls the position of the scrotum and testes. When cold or aroused this muscle contracts to bring the testes closer
What is the ideal temperature for the testes?
2 degrees less than body temp so 35
Describe the pathway taken during the descent of the testes
1) The testes develop intra abdominally near the kidneys
2) They are translocated inferiorly and anteriorly to the abdominal wall, travelling thru the inguinal canal
3) The gubernaculum testes pull the testes thru the abdomen
4) During the third trimester they move thru the abdominal wall and take with then a pocket of the peritoneal cavity
5) As the testes move thru the wall they are accompanied by the ductus deferens, bv, nerves, and lymphatics
Testes - length
Testes = 4-5 cm long
What covers the testes?
Testes are covered by:
- Tunica vaginalis
- Tunica albuginea
Describe the Tunic Vaginalis (4)
Tunica Vaginalis
- extension of the peritoneum
- is a serous membrane
- has a visceral and parietal layer
- covers the lateral and anterior surface of the testes
What covers the lateral and anterior surface of the testes?
The tunica vaginalis - covers the lateral and anterior surface of the testes
Describe the tunica albuginea (2)
Tunica albuginea
- fibrous coat or capsule
- extension penetrates the testes dividing it into 250-300 compartments called “testicular lobules”
What do testicular lobules contain
Testicular lobules contain:
- seminiferous tubules
- loose ct
- bv’s
Where are sperm produced?
Sperm are produced in the seminiferous tubules
How long are the seminiferous tubules?
Seminiferous tubules
- 80 cm long each
- 0.5 miles total
Define - spermatogenesis
Spermatogenesis: the process by which the seminiferous tubules of the testes produce sperm
Define - spermatogonia
Spermatogonia: stem cells that form during embryonic development
Describe the process of spermatogenesis
Spermatogenesis
1) LH, FSH and testosterone stimulate
2) Thru cell division form spermatogonia
3) spermatogonia -> primary spermatocytes
4) primary spermatocytes -> secondary spermatocytes
5) secondary spermatocytes -> pair of spermatids
6) Spermatids -> spermatozoa
Define - spermatogenesis
Spermatogenesis: maturation of spermatids resulting in spermatozoa
What’s is the process of spermatids maturing to spermatozoa?
spermatogenesis
What cells extend form the basal lamina to the lumen of the testes?
Sertoli cells
How are Sertoli cells connected?
Tight junctions - connect Sertoli cells
Sertoli cells - purpose (5)
Sertoli cells
1) Nourish and transport spermatogenic cells
2) Secretions regulate spermatogenesis
3) Create the blood-testes barrier
4) Support spermatogenesis and spermiogenesis
5) Secrete inhibin and androgen binding protien
spermiogenesis vs spermatogenesis
Spermatogenesis - The process by which haploid spermatozoa develop from germ cells in the seminiferous tubules of the testis.
Spermiogenesis - Spermiogenesis is the final stage of spermatogenesis, which sees the maturation of spermatids into mature, motile spermatozoa
What is the spermatic cord made of?
Spermatic cord = fascia, ct, nerves
Where is the spermatic cord, what does it attach to?
Spermatid cord
- wraps the bv, nerves and lymphatics that supply the testes
- starts at the deep inguinal ring, extends thru the inguinal canal and comes thru the superficial inguinal ring into the scrotum
What is the blood supply to the testes?
Testicular arteries
= branches of the abdominal aorta
Testicular veins
= The planiform plexus surrounds the testicular arteries
Describe testicular innervation
Autonomic NS
- sensory
How long are sperm
Sperm = 65 um long
Describe the structure of sperm and the significance of certain parts
Head
- contains the nucleus and acrosomal cap (bag of enzymes)
Neck
- contains the cellular components that form the flagellum
Middle piece
- mitochondria collar
Tail
- flagellum, source of movement
