Lecture 24 3/18/24

Question 1

What is the main function of the testes?

Answer 1

spermatogenesis

Question 2

How do FSH and LH act on the testes?

Answer 2

-FSH stimulates Sertoli cells
-LH stimulates testosterone production

Question 3

What is the tunica vaginalis?

Answer 3

layer outside of the tunica albuginea that surrounds the entire testicle

Question 4

What is the specific site of spermatogenesis?

Answer 4

seminiferous tubules

Question 5

What is the tunica?

Answer 5

-dense fibrous connective tissue capsule surrounding each testis
-extends inward to form a central septum

Question 6

How do the seminiferous tubules appear?

Answer 6

-highly coiled within the lobules
-converge into straight tubules leading to the rete testis

Question 7

What are the characteristics of the tissue layers within the seminiferous tubules?

Answer 7

-each tubule is surrounded by 1-4 layers of flattened smooth muscle
-smooth muscle supports the spermatogenic cells and Sertoli cells

Question 8

In which seminiferous tubule cells does spermatogenesis occur?

Answer 8

the most mature cells, closest to the lumen

Question 9

What are the characteristics of spermatogonia?

Answer 9

-most immature spermatogenic cells
-small, round cells with dark, round nuclei
-adjacent to basement membrane
-undergo meiotic division to produce primary spermatocytes

Question 10

What are the characteristics of spermatocytes?

Answer 10

-larger and more luminal than spermatogonia
-divided into primary and secondary spermatocytes

Question 11

How do primary and secondary spermatocytes differ?

Answer 11

-primary are in 1st meiotic division
-secondary are in 2nd meiotic division

Question 12

What are the characteristics of spermatids?

Answer 12

-formed after spermatocytes complete second meiotic division
-initially round with pale nuclei
-eventually become small and oval/elongated with dark heads and long, faint tails

Question 13

What are the characteristics of spermatozoa?

Answer 13

-divided into head, neck, and tail
-actively mobile
-head = nucleus covered by acrosome

Question 14

What are Sertoli cells?

Answer 14

nurse cells that provide mechanical and nutritive support for spermatogenic cells

Question 15

What are the characteristics of Sertoli cells?

Answer 15

-irregularly columnar
-extend from basal lamina to lumen
-indistinct boundaries
-numerous invaginations in cell membranes

Question 16

What are the characteristics of the interstitium?

Answer 16

-between the tubules
-highly vascularized connective tissue
-contains Leydig cells

Question 17

What are the characteristics of Leydig cells?

Answer 17

-eosinophilic granular to vacuolated cytoplasm
-large, round, often eccentric nucleus

Question 18

What is the function of Leydig cells?

Answer 18

produce testosterone

Question 19

What is the passageway through the ducts?

Answer 19

-rete testis
-testicular efferent ducts
-head, body, and tail of epididymis
-vas deferens
-urethra

Question 20

Why are there ciliated cells within the epithelium of the testicular efferent ducts?

Answer 20

to help with sperm movement

Question 21

What are the functions of the testicular efferent ducts?

Answer 21

-epithelial cells absorb luminal fluid produced during spermatogenesis
-ciliated cells move sperm through duct

Question 22

What are the characteristics of the epididymis?

Answer 22

-coiled tube
-contains head, body, and tail
-epithelium contains long apical stereocilia

Question 23

What are the functions of the epididymis?

Answer 23

-stereocilia have absorptive and secretory functions
-sperm undergo final maturation in middle segment
-tail is site of storage for mature spermatozoa

Question 24

What are the characteristics of the vas deferens?

Answer 24

-very thick muscularis
-highly folded mucosa

Question 25

What are the functions of the urethra?

Answer 25

-semen transport -urine transport

Question 26

What are the three portions of the urethra?

Answer 26

-prostatic -pelvic -penile

Question 27

Which accessory glands are present in the male?

Answer 27

-ampullary glands of vas deferens -seminal vesicles -prostate -bulbourethral glands -urethral glands

Question 28

What are the characteristics of the accessory glands?

Answer 28

-architecture of all is similar -secrete serous or mucinous fluids

Question 29

What do the ampullary glands empty into?

Answer 29

vas deferens

Question 30

Which species lack seminal vesicles?

Answer 30

carnivorous species

Question 31

What is contained in the fluid produced by the seminal vesicles?

Answer 31

-fructose -prostaglandins -coagulating proteins

Question 32

What are the characteristics of the prostate?

Answer 32

-encircles urethra as it leaves urinary bladder -consists of body and disseminated portion -secretions enhance sperm motility

Question 33

What are the characteristics of the bulbourethral glands?

Answer 33

-not found in dogs -secretes alkaline mucus-like fluid -fluid neutralizes acidity of residue in urethra and vaginal secretions

Question 34

What are the two parts of the penis?

Answer 34

-body -glans penis

Question 35

What are the two erectile tissues found in the penis?

Answer 35

-corpus spongiosum: surrounds urethra -corpus cavernosum: dorsal to urethra

Question 36

What are the three types of penis, based on connective tissue and smooth muscle?

Answer 36

-fibroelastic: connective tissue predominates -intermediate: smooth muscle and connective tissue in equal amounts -vascular: smooth muscle predominates

Question 37

What are the characteristics of the glans penis?

Answer 37

-expanded distal portion of the penis -contains erectile tissue continuous with corpus spongiosum -contains os penis in carnivores

Question 38

How does the prepuce of the glans penis appear in tomcats?

Answer 38

small, keratinized epidermal spines

Question 39

How does the prepuce of the glans penis appear in goats?

Answer 39

present urethral process