Lab 5

Question 1

What is flexion?

Answer 1

A decrease in a joint angle

Question 2

What is extension?

Answer 2

An increase in a joint angle

Question 3

What is the order of bones in a bird’s leg from proximal to distal?

Answer 3

Femur
Knee
Shank (Fibula & tibiotarsus)
Intertarsal joint
Tarso-metatarsus
Phalanges

Question 4

What is the order of bones in a human’s leg from proximal to distal?

Answer 4

Femur
Knee
Tibia (with small fibula)
Ankle
Tarsals
Metatarsals
Phalanges

Question 5

What colours does masson’s trichrome stain skeletal muscle, collagen, nuclei and bone?

Answer 5

Skeletal muscle = Red
Collagen = Green
Bone = red/pink in some places, blue/green in others
Nuclei = brown/black

Question 6

How good is the blood supply to the tendon?

Answer 6

Quite avascular

Question 7

In how many directions does collagen withstand tension?

Answer 7

2 directions, but one plane.

Question 8

How does the arrangement of collagen in the tendon change as it nears bone?

Answer 8

In purely the tendon, it is quite parallel, with about 20 fibres per bundle
As it nears the bone it becomes wavy and irreguar

Question 9

What is the difference between chicken and human RBCs?

Answer 9

Chicken RBCs have nuclei

Question 10

How are sharpey’s fibres formed?

Answer 10

Osteoblasts secrete osteoid onto collagen fibres already projecting into bone, calcifying it.

Question 11

What shape are muscle fibres in cross section?

Answer 11

Polyhedral

Question 12

What happens to the coarse collagen fibres in the tendon as they near the muscle?

Answer 12

They blend at the myotendinous junction, becoming attached to the sarcolemma

Question 13

What are the muscles of the chicken thigh from lateral to medial?

Answer 13

Lateral iliotibular muscle –> Iliofibular muscle –> Lateral knee flexor muscle –> medial knee flexor muscle

Question 14

Which muscle has a sling surrounding its tendon?

Answer 14

The iliofibular muscle

Question 15

What is superficial fascia?

Answer 15

The soft, weak layer of CT directly underlying the skin.

Question 16

Where is the origin vs. insertion of the lateral iliotibial muscle?

Answer 16

Origin is ileum of pelvis

Insertion is tibiotarsus of shank

Question 17

What is the corresponding muscle to the iliotibial muscle in humans?

Answer 17

The gluteus maximus

Question 18

Where does the iliofibular muscle insert?

Answer 18

The fibula

Question 19

What does the sling do?

Answer 19

Prevents the iliofibular muscle from bowstringing

Question 20

What is the corresponding muscle to the iliofibular muscle in humans?

Answer 20

The biceps femoris

Question 21

What is the corresponding muscle to the sling of the chicken leg in humans?

Answer 21

The short head of the biceps femoris

Question 22

Where is the lateral knee flexor?

Answer 22

It forms the posterior muscle of the thigh

Question 23

Where is the gastrocnemius muscle?

Answer 23

Below the knee of the chicken

Question 24

Where do the medial and lateral knee flexor muscles combine?

Answer 24

In their combined aponeurosis, culminating in a tendon that inserts on the tibiotarsis

Question 25

What is the anatomy of the combined knee flexor aponeurosis?

Answer 25

It is in two parts: A large anterior part inserts on the tibiotarsus, while the smaller posterior part joins a fibrous fascia on the medial surface of the shank, becoming a large tendon on the posterior side of the intertarsal joint

Question 26

What is the equivalent of the posterior knee flexor tendon in humans?

Answer 26

The achilles tendon

Question 27

What is the origin of the knee flexor muscles?

Answer 27

In the pelvis, posterior to the head of the femur.

The lateral knee flexor muscle origin is dorsal to that of the medial

Question 28

Where is the lateral knee flexor accessory muscle and how do we identify it?

Answer 28

It joins the anterior edge of the lateral knee flexor distally, with fibres at right angles to the axis of the thigh

Question 29

What is the function of the lateral knee flexor accessory muscle?

Answer 29

It prevents the lateral knee flexor from bowstringing

Question 30

What happens to the hip joint when the iliofibular muscle contracts?

Answer 30

The hip joint extends

Question 31

What happens to the hip joint when the long head of the biceps femoris contracts?

Answer 31

The hip joint extends

Question 32

What happens to the hip joint when the short head of the biceps femoris contracts?

Answer 32

Nothing

Question 33

What happens to the knee joint when the iliofibular muscle contracts?

Answer 33

The knee joint flexes

Question 34

What are the hamstring muscles of the human thigh?

Answer 34

The biceps femoris, semimembranous and semitendinosus muscles

Question 35

What are biarticulate muscles?

Answer 35

The cross two joints (usually hip and knee)

Question 36

Why is it easier to bend forward in a crouch than with the legs straight?

Answer 36

The hamstrings become less taut when the knees are bent due to their origin and insertions being closer together

Question 37

What are the phases in walking?

Answer 37

Heel strike
Foot flat
Mid-stance
Push off
Toe off
Mid swing
Heel strike

Question 38

Which phases of walking do the hamstrings contract in?

Answer 38

Heel strike, to decelerate the step and reduce impact.
Some action during right foot flat for balance
They also prevent excessive hip flexion.

Question 39

What are the equivalent muscles in the human to the medial and lateral knee flexors?

Answer 39

The semimembranous and semitendinous muscles.