Equine Hindlimb - Comparative Anatomy

Question 1

Labrum Acetabulare

Answer 1

fibrocartilage lip on the rim of the acetabulum
deepens the acetabulum of the horse

Question 2

Accessory ligament of the coxofemoral joint of the horse

Answer 2

extension of the prepubic tendon
passes through the acetabular notch to the end of the fovea capitis

Question 3

What is the function of the accessory ligament in the hip joint of the equine species?

Answer 3

limits movement of the joint to extension and flexion

Question 4

Describe the synovial sacs of the equine stifle and how they communicate with eachother, if at all

Answer 4

femoropatellar sac
lateral femorotibial sac
medial femorotibial sac

femoropatellar + medial femorotibial communicate in all horses

femoropatellar + lateral femorotibial comminicate in 25% of horses

NO communication between lateral and medial

Question 5

How many patellar ligaments are present in the equine stifle?

Answer 5

three: medial, middle and lateral

Question 6

Describe the relationship between the stifle and the hock in the horse

Answer 6

they move in synchrony

“stifle and hock are married”

Question 7

Parapatellar fibrocartilage

Answer 7

present on the medial angle of the patella of the horse
plays a role in the patellar lock mechanism

Question 8

Describe the Patellar Lock Mechanism

Answer 8

part of the stay apparatus of the equine hindlimb
muscular activity is virtually non-existent
medial trochlear ridge protrudes through the loop formed by the medial and middle patellar ligament, anf the patellar fibrocartilage
stifle is locked in extension

Question 9

Describe the movement of the tarsocural joint in the equine hindlimb

Answer 9

responsible for the outward movement of the hock during flexion
trochlea assists in turning the stifle outward to avoid the thoracic wall

Question 10

Which component articulations of the equine tarsal joint communicate?

Answer 10

tarsocural joint and proximal intertarsal joint
most moveable part fo the tarsal joint

Question 11

What is the function of the long plantar ligament of the equine hindlimb?

Answer 11

anchors the plantar surface of 4th tarsal and IV metatarsal
stabilizes the calcaneus when under force

Question 12

What is the cunean tendon in the equine hindlimb?

Answer 12

medial limb of the tendon of the cranial tibial muscle
inserts on tarsals 1 and 2
has the cunean bursa

Question 13

Describe the calcanean bursa

Answer 13

subcutaneous part: between skin and SDFT
subtendinous part: between SDFT and calcanean tuberosity

Question 14

Which tendon of the equine hindlimb is not covered by a tendon sheath?

Answer 14

only the SDFT

Question 15

Describe the gluteal muscles of the equine species?

Answer 15

very well developed

Question 16

What is unique about the superficial gluteals of the equine species?

Answer 16

the cranial and caudal parts of the superficial gluteals insert onto the third trochanter with a synovial bursa interposed between the tendon and third trochanter

Question 17

Desribe the nature of the leg muscles of the horse

Answer 17

tendinous nature - aids in weight bearing with less muscular activity while also preventing overextension of the joints

Question 18

Describe the perpneus tertious muscle in the horse

Answer 18

completely tendinous in horses

NOTE: absent in carnivores

Question 19

What is the origin of the peroneus tertious muscle in the horse?

Answer 19

extensor fossa of the femur with the long digital extensor

Question 20

What is the insertion of the peroneus tertious muscle in the horse?

Answer 20

divides distally and insets onto the tarsal bone and metatarsus

NOTE: only moves the hock

Question 21

What feature of the equine cranial tibial muscle gives rise to the cunran tendon?

Answer 21

medial branch of the cranial tibial branch
stronger branch

Question 22

What feature is unique to the stay apparatus of the equine hindlimb?

Answer 22

the reciprocal apparatus

Question 23

Describe the reicprocal apparatus of the equine hindlimb

Answer 23

part of the stay apparatus limited to the hindlimb
allows the stifle andf hock to move in unicin

Question 24

What are the components of the reciprocal appartatus?

Answer 24

peroneus tertus and superficial digital flexor

Question 25

What are the main nerves of the equine hindlimb?

Answer 25

femoral, obturator, and sciatic

Question 26

What are the main nerves of the distal aspect of the equine hindlimb?

Answer 26

tibial and common peroneal nerves come off of the sciatic nerve

Question 27

What nerve supples the craniolateral muscles of the equine hindlimb?

Answer 27

common peroneal nerve - branches to superficial and deep branches continues on the dorsal surface of the digit as the medial and lateral dorsal digital nerves

Question 28

What nerve supplies the caudal group of muscles in the equine hindlimb?

Answer 28

tibial nerve - branches to medial and lateral plantar nerves with a communicating branch lateral plantar nerve then branches to medial and lateral plantar metatarsal branches

Question 29

What is the main artery of the equine hindlimb?

Answer 29

femoral artery (a direct branch of the external iliac artery)

Question 30

What are the branches of the femoral artery in the equine hindlimb?

Answer 30

saphenous - superfically on medial and caudal aaspect popliteal - name change at the caudal aspect of the stifle

Question 31

What are the branches of the saphenous artery in the equine hindlimb?

Answer 31

medial and lateral plantar arteries

Question 32

What are the branches of the popliteal artery in the equine hindlimb?

Answer 32

cranial tibial and caudal tibial arteries

Question 33

What arteries form the deep plantar arch of the equine hindlimb?

Answer 33

perforating tarsal artery (branch of the cranial tibial) and the branches of the medial and lateral plantar artery

Question 34

What does the deep plantar arch in the equine hindlimb give rise to?

Answer 34

gives rise to the medial and lateral plantar metatarsal arteries

Question 35

Describe the course of dorsal metatarsal artery III down the equine forlimb?

Answer 35

divides just proximal to the fetlock into medial and lateral plantar proper digital arteries dorsal branches go to dorsal surfaced of proximal and middle phalanges

Question 36

What is the parent branch of the dorsal metatarsal artery III in the equine hindlimb?

Answer 36

branch of the cranial tibial artery

Question 37

How do the vessels of the equine hindlimb terminate?

Answer 37

terminate within the terminal arch in the third phalanx same like the forelimb

Question 38

What comprises the equine foot?

Answer 38

foot = hoof + everything inside of it

Question 39

What are the topographical regions of the equine hoof wall?

Answer 39

toe, quaters, heels, bars

Question 40

Describe the thickness of the equine hoof wall

Answer 40

thickest at the toes and thins toward the heel

Question 41

Describe the hoof capsule of horses

Answer 41

skin derivative enclosing the third phalanx no blood vessels or nerves

Question 42

What is another name for the coronet

Answer 42

coronary band

Question 43

What is the coronary band?

Answer 43

junction between the skin and hoof

Question 44

Describe the stratum externum

Answer 44

very thin outer most portion of the epidermis of the hoof

Question 45

Describe the wall substance of the equine hoof

Answer 45

tubules held together by amorphous intertubular horny material

Question 46

What are the parts of the stratum externum in the equine hoof?

Answer 46

periople: narrow band, soft rubbery horn, fluid reservior stratum tectorium: impervious to water, parallel proximo-distal lines

Question 47

Describe the stratum medium of the epidermis of the equine hoof?

Answer 47

very thick begins at the coronary groove papillae produced by coronary dermis pigmented

Question 48

What makes up the stratum medium of the epidermis of the equine foot?

Answer 48

formed by tubules and intertubular horn

Question 49

Describe the stratum internum of the epidermis of the equine hoof?

Answer 49

non pigmented made up of keratinzed primary laminae and non keratinized secondary laminae

Question 50

Stratum internum aka

Answer 50

epidermal laminae

Question 51

Describe epidermal laminae

Answer 51

insensitive laminae form the laminae of the bar

Question 52

Describe the dermis of the equine foot

Answer 52

vascular and sensitive attaches hoof wall to internal foot structures provides the wall with nourishment

Question 53

Describe the sole of the equine hoof

Answer 53

fills the spce between the wall and frog concave softer than the wall horn

Question 54

What are the angles of the sole (equine hoof)

Answer 54

parts between bars and quaters

Question 55

What is the frog of the equine hoof?

Answer 55

plays a role in weight bearing and shock absorbing located between the heels wedge shaped

Question 56

What is the bulb of the heel in the equine hoof?

Answer 56

base of the frog as it continues proximally separated by intratoric fossa

Question 57

Describe the digital cushion of the equine hoof

Answer 57

in young animals: wedge shaped, fibro-fatty composition in adult animals: fibrocartilagenous wedge lies abover crura of the frog

Question 58

Describe the periople dermis of the equine hoof

Answer 58

narrow, pale produce horn of stratum externum

Question 59

Describe the coronary dermis of the equine hoof

Answer 59

thick, pigemented in the coronary groove papillae produces most of the hoof wall

Question 60

Describe the laminar dermis of the equine hoof

Answer 60

aka epidermal laminae has primary and secondary laminae colorless provides a very strong connection between walls and bars

Question 61

Describe the sole dermis of the equine hoof

Answer 61

makes direct contact with the sole attached to the under surface of the third phalanx

Question 62

Describe the frog dermis of the equine hoof

Answer 62

densely covered with plump papillae

Question 63

Describe the white line of the equine hoof

Answer 63

thin, soft, pale horn junction of the hoof wall and sole