Chapter 4

Question 1

The wings of the atlas & sacrum are modivications of what?

Answer 1

modifications of transverse processes

Question 2

How does the orientation of the wing of the ilium change as a calf or foal mature?

Answer 2

Wing of ilium is originally vertical in orientation, but changes to a more horizontal orientation as the animal matures.

Question 3

What is the functional reason for the orientation of the wing of the ilium changing positions during maturation?

Answer 3

to support increasing visceral weight as more normal forage begins to be consumed
wide pelvis helps form a broad sling to support the visceral weight

Question 4

Compare fore vs hind limb extrinsic muscles. Why is one group insignificant?

Answer 4

hind limb muscles have a much greater muscle mass due to the propulsive, rather than supportive function
extrinsic muscles not as important in the hind limb during force transfer because the sacroiliac joint facilitates much of the force transfer from limbs to axial skeleton

Question 5

What is the topographic relationship of longitudinal and circular muscle in the gut?

Answer 5

muscle layers in the gut are composed of an inner circular layer and an outer longitudinal layer

Question 6

What are 2 specialized longitudinal muscle structures of the large intestine?

Answer 6

muscle coat concentrated in a number of bands, which form sacculations when the muscles contract

Question 7

What species have specialized longitudinal muscle structures in their large intestine?

Answer 7

horse
pig
human

Question 8

Describe 2 smooth muscles that attach to bone.

Answer 8

rectococcygeus (from longitudinal coat of rectum to ventral part of caudal vertebrae)
retractor penis/clitoris (vertically directed and deep to levator ani muscle

Question 9

The pelvic diaphragm is an extremely important structure in human anatomy because it supports the abdominal viscera in standing (or sitting) persons. What is the structure of it in domestic animals and what is the value of it in quadrupeds since it does not support the abdominal viscera?

Answer 9

composed of coccygeus and levator ani muscles that arise from the inside or edge of the pelvis & attach on terminal parts of the digestive U-G tracts & tail
provides the main visceral pressure of abdominal press (the grunt)

Question 10

What is the perineum?

Answer 10

deep fascia & muscle, seals pelvic outlet around terminal portion of the if and digestive tracts

Question 11

What disorders occur in the perineum?

Answer 11

Dog: pernineal hernias
Mare: perineal lacerations during parturition

Question 12

Compare the sacrosciatic ligament of ungulates with the sacrotuberous ligament of the dog.

Answer 12

Sacrosciatic: broad, flat & covers a huge area and the caudal edge corresponds to the sacrotuberous
Sacrotuberous: cordlike

Question 13

How are the greater and lesser sciatic foramen formed?

Answer 13

Formed by the sacrotuberous & sacrosciatic ligaments

Question 14

What nerve and artery passes through the greater sciatic foramina in the horse & ox?

Answer 14

sciatic nerve (horse & ox)
cranial gluteal artery (horse & ox)

Question 15

What passes through the lesser sciatic forament in the horse and ox?

Answer 15

Horse: internal obturator tendon
Ox: caudal gluteal artery

Question 16

What bones form the acetabulum?

Answer 16

ilium, ischium, pubis & acetabular bones

Question 17

Compare the pelvic floor of the cow & horse.

Answer 17

cow: floor is concave
horse: floor is flat in the mare

Question 18

Why are the tuber ischii prominent in cattle, but not in the horse?

Answer 18

In the horse, they are covered by the vertebral origin of the semimembranous muscle

Question 19

What forms the pelvic inlet (bony pelvis)?

Answer 19

sacrum
iliac shafts
pubis

Question 20

Whata forms the pelvic outlet?

Answer 20

bone & ligament
Cd1
sacrotuberous ligament
ischial arch

Question 21

What part of the pelvic region is widest in the fetus and what problems could this cause?

Answer 21

widest at trochanters in the fetus

can cause hip lock at the pelvic inlet during calving

Question 22

Differentiate between colli/coli

Answer 22

Colli: refers to collar or neck
Coli: refers to intestines or colon

Question 23

Differentiate between longus/longissimus

Answer 23

Longus: long
Longissimus: longest

Question 24

Differentiate between peroneal/perineal

Answer 24

Peroneal: pertains to the outer side of the leg
Perineal: pertains to the perineum/pelvis

Question 25

Differentiate between ilium/ileum

Answer 25

Ilium: bone of the pelvis
Ileum: most distal part of the small intestine

Question 26

Differentiate between sciatic/ischiatic

Answer 26

Sciatic & ischiatic both pertain to the ischium

Question 27

Differentiate between estrus/estrous

Answer 27

Estrus: noun
Estrous: adjective form

Question 28

Differentiate between prepuce/preputial

Answer 28

Prepuce: noun
Preputial: adjective form

Question 29

Differentiate between crus/crura/crural

Answer 29

Crus: singular noun
Crura: plural noun
Crural: adjective form

Question 30

What is the functional significance of the sacroiliac joint?

Answer 30

receives transfer of force from hind limb to the axial skeleton

Question 31

Sacroiliac luxation can be detected from a caudal view by noting unilateral elevation of the tuber sacrale. How could this be related to estrus in cattle?

Answer 31

Relaxin hormone relaxes the joint and promotes its elevation (psuedoluxation)

Question 32

The birth canal is defined by ?

Answer 32

pelvic inlet & pelvic outlet

Question 33

Where do problems (dystocia) occur during parturition and why is this paradoxyl?

Answer 33

pelvic inlet
Paradoxyl because the inlet is much larger, but problems occur there more often because the outlet is quite elastic in response to hormones

Question 34

How do hormones figure in to the pelvic inlet & outlet?

Answer 34

Relaxin relaxes the pelvic outlet and the sacroiliac joint

Question 35

The terms hook bones and pin bones are often used in dairy cow judging. What do these terms refer to?

Answer 35

hook bones: tuber coxae

pin bones: tuber ischii

Question 36

What is the significance of tuber ischii bones with regards to calving?

Answer 36

wider tuber ischii facilitate greater ease during parturition

Question 37

Differentiate between pelvic diaphragm and urogenital diaphragm.

Answer 37

pelvic diaphragm: composed of 2 muscles; accommodates visceral pressure for abdominal press; attaches on the terminal parts of digestive and UG tracts; more dorsal
Urogenital: more ventral; fibrous connection between ischial arch & vestibule: functions to anchor the caudal part of the tract against the pull of a gravid uterus

Question 38

What is the structure and function of the constrictor vestibulae muscle in dog & cow?

Answer 38

Dog: holds the male in the “tie” by a sphincter like action caudal to bulbus glandis
Cow: U-shaped; blends with the caudal ventral part of the levator ani m. near external anal sphincter; just caudal to major vestibular gland; covers retractor clitoris muscle; contraction narrows the genital passage & raises a ridge in its floor & makes the vulvar opening gape

Question 39

Which of the following muscles are smooth muscles: levator ani; retractor penis; constrictor vestibulae; coccygeus; rectococcygeus; internal anal sphincter; and external anal sphincter

Answer 39

retractor penis
internal anal sphincter
rectococcygeus

Question 40

Which of the following muscles are striated muscles: levator ani; retractor penis; constrictor vestibulae; coccygeus; rectococcygeus; internal anal sphincter; and external anal sphincter

Answer 40

levator ani
constrictor vestibulae
coccygeus
external anal sphincter