Lab 5: Musculoskeletal System Flashcards Preview

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Flashcards in Lab 5: Musculoskeletal System Deck (40)
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What is the basic unit of the musculoskeletal system?

A bone moved by a muscle acting through a tendon.


Where is the movement of the bone permitted?

At a joint


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



What is meant by proximal and distal?

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.


What is meant by medial and lateral?

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


What is meant by superficial and deep?

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


What is meant by origin and insertion?

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


What is meant by flexion and extension?

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


What does an avian thigh consist of?

Hip to knee and contains the femur.


Why is the chicken thigh hidden from view?

It is tucked alongside the torso of the bird.


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

Only from the knee joint down.


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

Lateral: skin
Medial: raw flesh


What is the chicken leg/shank made up of?

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.


What does the bird foot comprise of?

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


What makes up a tendon in a slide?

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


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

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.


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

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.


What is the function of Sharpey fibres?

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


Describe the appearance of osteoclasts.

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


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

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.


In which two locations is the superficial fascia stronger?

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.


Describe the lateral iliotibial muscle of the thigh.

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.


What is the combined tendon of the knee flexor muscles?

A thin and ribbon like aponeurosis


What are the two parts of the aponeurosis?

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).


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

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.


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

The pelvis is concealed beneath connective tissue and muscle.


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

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.


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

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.


Describe angular movements.

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.


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

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).