Carnivore Anatomy Lab 7 Introduction

CONTENTS:

Lab Objectives
Anatomical Terms
Instructor Commentary
Dissection Steps
Dissection Videos
Dissection Images

Lab Objectives:

• Dissect the four (six in the cat) major muscles comprising caudal muscles of the crus (leg):
      - gastrocnemius m. (medial and lateral heads)
      - superficial digital flexor m. (has a calcanean bursa)
      - deep digital flexor m. (lateral and medial heads)
      - popliteus m.
   and in the cat:
      - soleus m., a third head of the cat gastrocnemius m. (absent in dogs)
      - caudal tibial m., positioned between lateral & medial heads of deep digital flexor m.

•Identify components of the common calcanean tendon

• Examine pelvic limb joints:
      - sacroiliac joint
      - pelvic symphysis
      - hip joint (ligament of head of femur & transverse acetabular ligament)
      - stifle joint (collateral, cruciate, & femoropatellar ligaments; and bilateral menisci)

CONTENTS

Anatomical Terms:

Pelvic Limb: muscles & fascia (continued)

        Caudal Muscles of the Leg
        gastrocnemius m.
        soleus m. (cat)
        caudal tibial m. (cat)
        superficial digital flexor m.
        common calcanean tendon
        calcaneal bursa
        deep digital flexor m.
                lateral digital flexor m.
                medial digital flexor m.
        flexor retinaculum
        popliteus m. (with sesamoid bone in tendon of origin)

Pelvic Limb: joints
        symphysis pelvis
        sacroiliac joint
        sacrotuberous ligament (absent in cat)
        hip (coxofemoral) joint
                ligament (round ligament) of the femoral head
                transverse acetabular ligament
                acetabular lip
        knee (stifle) joint (femorotibial, femoropatellar) [palpate]
                patella / patellar ligament [palpate]
                meniscus (lateral & medial menisci)
                collateral ligaments (medial & lateral) [palpate]
                cruciate ligaments (cranial & caudal)
        tarsal joint (tibiotarsal, proximal intertarsal, distal intertarsal, tarsometatarsal) [palpate]
        metatarsophalangeal joint [palpate]
        interphalangeal joint (proximal, distal) [palpate]

        Note:
                coxa [Latin] = hip (os coxae = bone of the hip)
                poples [Latin] = ham (popliteal pertains to the knee)

CONTENTS

Instructor Commentary:

Muscles of the thigh (biceps femoris, semitendinosus, and gracilis muscles) contribute to the calcanean tendon via crural deep fascia. Thus a dog could continue to stand even if its gastrocnemius and superficial digital flexor muscles were paralyzed.

Belying its name, the superficial digital flexor m. is mainly an antigravity, weight-support muscle. Because its tendon attaches to the tuber calcanei, the muscle cannot flex digits independently of extending the hock.

The soleus m., which is found in the cat and many other species, is of interest to physiologists because it represents an isolated population of fatigue resistant muscle fibers (Type I). Such fibers are mixed together with Type II muscle fibers in the canine gastrocnemius m.

While the term stifle (femorotibial joint) is generally recognized by rural (farm oriented) people, the term may be unfamiliar to urban persons. This is a reason for substituting "knee" for "stifle". However, this creates a problem in that the term knee is applied also to the carpus of farm animals.

CONTENTS

Dissection Steps:

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Dissection Videos:

CONTENTS

Dissection Images:

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