Oviduct & ovary

Question 1

Oviduct: briefly explain what they are

Answer 1

The oviducts (aka fallopian tubes, uterine tubes, salpinx) are tubes running from tip of each uterine horn to each ovary

Question 2

Utero-tubal junction

Answer 2

The UTJ is the transition point between the uterus & oviduct – can act as a physical barrier to limit cell/fluid movement

In some species, constriction at the UTJ (muscular or oedema) can restrict:

• Entry of sperm (cow, sow) or
• Exit of oocytes/embryos (mare, ewe)

Question 3

Oviduct regions

Answer 3

Question 4

Isthmus Histology

Answer 4

Simple mucosa & thick muscle layer

Question 5

Ampulla Histology

Answer 5

Elaborately folded mucosa (incr. SA), ciliated (help move oocytes to uterus)and thin muscle layer.
Also has secretory cells.
Poorly developed muscle layer.

Question 6

Infundibulum

Answer 6

The terminal potion of the oviduct. It has finger-like projections (frimbriae) which greatly increase it surface area.

Infundibulum catches oocyte as released from ovary during ovulation – these enter ampulla through ostium (opening)

Question 7

Species Differences cow vs ewe

Answer 7

Similar but more extensive infundibulum in cow than ewe.

Question 8

Species Differences mare

Answer 8

Mare has unique structure – the ovarian fossa (closely associated with infundibulum).
Unlike in other species, the mare always ovulates at this same location, close to infundibulum.
The mare also has a highly convoluted oviduct (R pic)

Question 9

species differences sow and bitch

Answer 9

The sow and bitch have a prominent ovarian bursa (made of mesovarium/mesosalpinx) enclosing the ovary – the infundibulum is part of this structure.
Bitch = only have 1 opening

Question 10

ovary: what is it responsible for in females?

Answer 10

• producing female gamete, the oocyte

Question 11

What are the four regions of the oviduct?

Answer 11

Four distinct regions

1. utero-tubal junction (UTJ)
2. Isthmus (uterine end, thinner)
3. Ampulla (ovarian end, thicker)
4. Infundibulum (funnel shaped opening)

Question 12

What is the role of the oviduct

Answer 12

Role of oviduct is to transport & support oocytes (pre and post-fertilisation) and sperm

Oviduct is where fertilisation occurs not in uterus.

Question 13

Ovaries are paired and cells undergo cyclical changes. T or F?

Answer 13

True

Question 14

Ovarian structure: name the 2 distinct regions of the ovary

Answer 14

• the cortex (external), containing growing oocytes
• the medulla (central) containing vasculature, nerves and lymphatics

Question 15

Ovaries: the cortex is external and the medulla is central in the mare, T or F?

Answer 15

• False, the mare is the opposite so their cortex is central and medulla is external unlike other species

Question 16

What does the cortex contain?

Answer 16

• growing oocytes

Question 17

what does the medulla contain?

Answer 17

vasculature, nerves and lymphatics

Question 18

where does ovulation occur in horses/mares?

Answer 18

ovulation at the ovulation fossa

Question 19

What species can have ovulation at any point of the ovary?

Answer 19

Every species but the mare..

• cow
• sheep
• pig
• dog
• cat

Question 20

What species ovulate only at the ovulation fossa?

Answer 20

the mare

Question 21

What re the 5 types of follicles from immature to mature?

Answer 21

1. primordial
2. primary
3. secondary
4. tertiary (developing antral)
5. antral (fluid filled follicles)

Question 22

What hormone is predominant in corpus luteum?

Answer 22

progesterone