comparative reproductive anatomy SDL

Question 1

outline the path sperm travel through the male reproductive tract

Answer 1

1. Seminiferous Tubules
2. Straight Tubules
3. Rete Testis
4. Efferent Ductules
5. Epididymal Duct in Head of Epididymis
6. Epididymal Duct in Body of Epididymis
7. Epididymal Duct in Tail of Epididymis
8. Deferent Duct (Vas Deferens)
9. Ejaculatory Duct
10. Urethra

Question 2

what muscles are located in the scrotum

Answer 2

• cremaster muscle
• dartos muscle

Question 3

what type of muscle is the cremaster muscle

Answer 3

skeletal muscle

Question 4

what type of muscle is the dartos muscle

Answer 4

smooth muscle

Question 5

what is the origin of the testicular arteries

Answer 5

abdominal aorta

Question 6

Although males do not have a vagina, they have a vaginal cavity (see drawing). What is in this cavity and why is it so?

Answer 6

The vaginal cavity in males refers to the tunica vaginalis, a serous membrane that covers the testes. It consists of two layers: the visceral layer (which covers the testes) and the parietal layer (which lines the scrotal cavity). The space between these layers contains a small amount of serous fluid, which allows the testes to move smoothly within the scrotum, reducing friction and preventing injury. This cavity is analogous to the peritoneal cavity, from which it is derived embryologically as the testes descend from the abdominal cavity into the scrotum.

Question 7

In the horse and most other domestic species, the tail of the epididymis is directed caudally.
Which species show a completely different orientation of the testes (and consequently the epididymis)?

Answer 7

• Pig (Boar): In pigs, the testes are oriented in such a way that the tail of the epididymis is positioned dorsally (toward the back).
• Cat (Tomcat): In cats, the testes are oriented with the tail of the epididymis directed toward the anus, and the long axis of the testes is vertical rather than horizontal.
• Elephant: In elephants, the testes remain within the abdominal cavity, so their orientation is not as clearly defined as in scrotal species.

Question 8

what is the function of the gubernaculum

Answer 8

The gubernaculum is a fibrous structure that plays a crucial role in the development and descent of the testes during fetal development.

Testicular Descent: During embryonic development, the testes form near the kidneys in the abdominal cavity. The gubernaculum anchors the testes to the developing scrotum. As the fetus grows, the gubernaculum does not elongate, while the rest of the body does. This differential growth “pulls” the testes downward through the inguinal canal and into the scrotum.
Post-Descent: After the testes have descended, the gubernaculum regresses and becomes a small, vestigial structure in the adult. It also helps to stabilize the position of the testes within the scrotum, preventing them from twisting, which could lead to conditions like testicular torsion.

Question 9

label

Answer 9

Question 10

Answer 10

Question 11

Question 12

Question 13

This histological image shows the epithelium of a seminiferous tubule. Identify the indicated cells.

Question 14

Answer 14

1. uterine horn
2. uterine body
3. cervix
4. urinary bladder
5. ureter
6. clitoris

Question 15

Answer 15

1. rectus
2. urinary bladder
3. cervix
4. uterus
5. vagina
6. vestibule
7. ovary
8. mammary gland

Question 16

what fold of tissue forms the ovarian bursa

Answer 16

mesosalpinx

Question 17

list the major supporting ligaments of the repro tract and their roles

Answer 17

• Broad ligament: supports and suspends the ovaries, oviduct, uterus and, cervix and cranial vagina. houses vascular supply, lymphatic drainage and nerves
• Round ligament of the uterus: runs caudal from tip of the uterine horn to the inguinal canal
• Suspensory ligament: tethers the ovary to the dorsal abdominal cavity
• Proper/ utero-ovarian ligament: support the ovary

Question 18

From which vascular trunk do the ovarian arteries arise from?

Answer 18

direct branch of the aorta

Question 19

To which vascular trunk do the ovarian veins drain?

Answer 19

caudal vena cava

Question 20

In which species are the ovarian artery and ovarian vein not intertwined?

Answer 20

mare

Question 21

Answer 21

a: uterine horn
b: oviduct
c: broad ligament
d: uterine body
e: cervix
f: anterior vagina
g: vestibule
h: vagina
i: labia/clitoris

Question 22

The uterine blood supply in the bitch and queen differs from the general pattern.

What is the main difference and what consequence does this have for spaying these animals?

Answer 22

• uterine artery from internal iliac artery isnt present
• lack of anastomosis with the ovarian artery in the broad ligament (only have to perform 2 ligations)

Question 23

Which species has a cervix with inter-digitating prominences?

Answer 23

sow

Question 24

In which species, would you find cervical rings?

Answer 24

• bitch and queen has single
• cow, ewe and sow has multiple

Question 25

In which species, does ejaculation occur into the uterus?

Answer 25

• mare
• sow

Question 26

ovary

Answer 26

top arrow: dead follicle
middle: primary follicles
bottom: primordial follicles

Question 27

ovary
- what is encircled in yellow
- what structure is found between the 2 arrows

Answer 27

yellow: primary follicle
arrows: zona pellucida

Question 28

Answer 28

a: corpus luteum
b: follicular fluid
c: blood vessels (RBC within)
d: venule