Lab 5: Musculoskeletal System

Question 1

What is the basic unit of the musculoskeletal system?

Answer 1

A bone moved by a muscle acting through a tendon.

Question 2

Where is the movement of the bone permitted?

Answer 2

At a joint

Question 3

How many different muscles are there in the chicken thigh and leg?

Answer 3

36

Question 4

What is meant by proximal and distal?

Answer 4

P: nearer to the point of attachment of a limb or part
D: further away from the point of attachment from a limb or part.

Question 5

What is meant by medial and lateral?

Answer 5

M: nearer to the mid-line of the body
L: further away from the mid-line of the body

Question 6

What is meant by superficial and deep?

Answer 6

S: towards or on the surface of the body
D: away from the surface of the body

Question 7

What is meant by origin and insertion?

Answer 7

O: a muscle’s attachment to the bone that moves the least.
I: a muscle’s attachment to the bone which moves the most.

Question 8

What is meant by flexion and extension?

Answer 8

F: to decrease a joint angle
E: to increase a joint angle

Question 9

What does an avian thigh consist of?

Answer 9

Hip to knee and contains the femur.

Question 10

Why is the chicken thigh hidden from view?

Answer 10

It is tucked alongside the torso of the bird.

Question 11

What part of the bird’s lower limb extends outside the body?

Answer 11

Only from the knee joint down.

Question 12

What surface of the chicken leg is covered with skin and which side is not?

Answer 12

Lateral: skin
Medial: raw flesh

Question 13

What is the chicken leg/shank made up of?

Answer 13

Between knee and ankle.
In it, the leg bones (large tibia and small fibula) and the proximal foot bones (tassels) have been fused together to form a single long bone (tibiotarsus) with the fibula remaining as a slender bone partly fused along side it.

Question 14

What does the bird foot comprise of?

Answer 14

Four digits supported by phalanges , which are the bones of our toes.

Question 15

What makes up a tendon in a slide?

Answer 15

Closely-packed, blue/green collagen fibres. In some places, they run in bundles, perhaps 20 fibres per bundle.

Question 16

What is the appearance of a slide of the bone of the fibula?

Answer 16

Hydroxyapatite matrix varies in colour from red/pink to blue/green. Numerous osteocytes are embedded in their tiny lacuna within the matrix. There are larger medullary spaces in the bone that contain soft tissue (bone marrow) that is shrunken and poorly preserved. Contains bold cells (red in colour and have nuclei) and much larger multinucleated osteoclasts.

Question 17

What is the bone surrounded by for most of its circumference? How is it attached with areas of no periosteum?

Answer 17

Fibrous periosteum to which the tendon is attached.
Tendon is directly attached to bone without an intermediate zone of periosteum in some places. In these places, collagen fibres of the tendon can be seen entering the bony matrix of the fibula. These are called Sharpey fibres.

Question 18

What is the function of Sharpey fibres?

Answer 18

They transmit forces from the muscle tendon directly to the bone matrix.

Question 19

Describe the appearance of osteoclasts.

Answer 19

A single layer of plump purple cells sitting on the bone surface beneath the periosteum.

Question 20

Why does the skin come away easily from the chicken leg?

Answer 20

There is a soft, weak layer of connective tissue (superficial fascia) between the skin and the thin sheet of connective tissue (deep fascia) covering the underlying muscle.

Question 21

In which two locations is the superficial fascia stronger?

Answer 21

1) Around the intertarsal joint at the distal end of the leg.
2) At the proximal end of the thigh, where it joins the pelvis.

Question 22

Describe the lateral iliotibial muscle of the thigh.

Answer 22

It has its origin on the ilium of the pelvis, and it inserts on the tibio-tarsus of the shank. It is a broad, flattened muscle on the lateral surface of the thigh. Similar in shape and position to the gluteus maximus of the human buttock and thigh.

Question 23

What is the combined tendon of the knee flexor muscles?

Answer 23

A thin and ribbon like aponeurosis

Question 24

What are the two parts of the aponeurosis?

Answer 24

A larger part inserts on the tibiotarsus (anterior), and a smaller part turns and joins a dense fibrous fascia on the medial surface of the shank (anterior).

Question 25

What does the fascia become distally? What is this equivalent to in the human?

Answer 25

A large strap-like tendon on the posterior side of the intertarsal joint. This is equivalent to the calcaneal tendon (Achilles tendon) in the human leg.

Question 26

Why is it difficult to discover the origins of the knee flexor muscles?

Answer 26

The pelvis is concealed beneath connective tissue and muscle.

Question 27

Near its distal end, how is the lateral knee flexor joined on its anterior edge?

Answer 27

By a short, flattened muscle. The fibres of this muscle run at right angles to the long axis of the thigh. It is an accessory muscle to the lateral knee flexor, called the lateral knee flexor accessory muscle.

Question 28

Describe gliding movement. What can gliding be combined with? Give examples of where this movement is found.

Answer 28

A simple movement in which nearly flat bone surfaces move back and forth and from side to side with respect to one another. There is no significant alteration of the angle between the bones. Gliding movements are limited in range due to the structure of the articular capsule and associated ligaments and bones; however, these sliding movements can also be combined with rotation. The intercarpal and intertarsal joints are examples of articulations where gliding movements occur.

Question 29

Describe angular movements.

Answer 29

There is an increase or decrease in the angle between articulating bones. The major angular movements are flexion, extension, lateral flexion, hyperextension, abduction, adduction, and circumduction.

Question 30

What is the opposite movement to flexion? Describe each. Both movements usually occur along what plane?

Answer 30

Extension
F: there is a decrease in the angle between the articulating bones.
E: there is an increase in the angle between articulating bones, often to restore a part of the body to the anatomical position after it has been flexed.
Both movements usually occur along the sagittal plane (forward and backward).

Question 31

Give two examples of flexion that does not occur along the sagittal plane.

Answer 31

• Flexion of the thumb involves movement medially across the palm.
• Movement of the trunk sideways to the right or left at the waist. This movement, which occurs along the frontal plane and involves the intervertebral joints is called lateral flexion.

Question 32

What is meant by hyperextension?

Answer 32

Continuation of extension beyond the anatomical position.

Question 33

Give examples of hinge joints. What is hyperextension of these joints prevented by?

Answer 33

Elbow, interphalangeal, and knee joints

Prevented by the arrangement of ligaments and the anatomical alignment of the bones.

Question 34

What is meant by abduction? What is another name for it?
What is meant by adduction? What is another name for it?
What plane do these movements occur along?

Answer 34

Movement of the bone away from the midline. (Radial deviation)
Movement of the bone towards the midline (Ulnar deviation)
Both movements usually occur along the frontal plane.

Question 35

Describe abduction and adduction of the thumb.

Answer 35

Abduction: thumb moves away from the palm in the sagittal plane.
Adduction: thumb moves towards the palm in the sagittal plane.

Question 36

What is meant by circumduction?

Answer 36

Movement of the distal end of a body part in a circle. It is not an isolated movement but rather a continuous sequence of flexion, abduction, extension, adduction and rotation of the joint. It does not occur along a separate axis or plane of movement.

Question 37

Why is circumduction more limited in the hip joints than the shoulder joints?

Answer 37

Due to the tension on certain ligaments and muscles and the depth of the acetabulum in the hip joint.

Question 38

What word is used to the describe the body lying facing down and up?

Answer 38

Down: prone position
Up: supine position

Question 39

What is meant by sagittal plane? Describe the alternatives.

Answer 39

A vertical plane that divides the body or organ into right and left.
When such a plane passes through the midline of the body, and divides it into equal sides, it is called a midsagittal plane or median plane.
If the sagittal plane does not pass through the midline, it is called a parasagittal plane.

Question 40

What is a frontal plane, transverse plane, and oblique plane?

Answer 40

Frontal/coronal plane divides the body into anterior and posterior.
Transverse/cross-sectional/horizontal plane divides the body into superior and inferior.
Oblique: Passes through the body or organ at an oblique angle.