Introduction to the Limbs

Question 1

What is the origin of a muscle?

Answer 1

Usually at the proximal end of the muscle which remains fixed during muscular contraction

Question 2

What is the insertion of a muscle?

Answer 2

Usually the distal of the muscle where the muscle moves when contracted

Question 3

What direction do muscles move during contraction?

Answer 3

Muscle usually move from the insertion to the origin direction. There are some cases where the muscles move and shorten in both directions

Question 4

What is a concentric contraction?

Answer 4

The muscle shortens during contraction

Question 5

What is an eccentric contraction?

Answer 5

The muscle elongates while under tension due to an opposing force greater than the muscle generates

Question 6

What are the two types of muscle contraction?

Answer 6

Isometric: size of muscles stays the same but tone increases
Isotonic: Tone of the muscle stays the same but the size changes, usually shortens

Question 7

What is a prime mover?

Answer 7

Muscle(s) that plays the primary role in moving a body part

Question 8

What is an agonist?

Answer 8

Muscle(s) that acts directly to produce desired movement

Question 9

What is a synergist muscle?

Answer 9

Muscle(s) which prevent unwanted movements that may hinder movements wanted from the prime movers

Question 10

What is an antagonist muscle?

Answer 10

Muscle(s) which directly oppose a movement

Question 11

What is a fixating muscle?

Answer 11

Muscle(s) that provide the necessary support to assis tin holding the rest of the body in place while a movement occurs

Question 12

What is superficial fascia and explain its function

Answer 12

Superficial fascia is just beneath the skin and contains adipose tissue (fat).

Function: Superficial fascia facilitates movements of the skin.
It serves as a soft medium for the passage of nerves and vessels to the skin.
It conserves body heat because by nature, fat is a bad conductor of heat.

Question 13

What is deep fascia and explain its function

Answer 13

Deep fascia is beneath superficial fascia

Function: Deep fascia creats septae to be made between muscles to seperate them into compartments. These septae form passages for blood vessels and nerves to pass through

Question 14

What is compartment syndrome?

Answer 14

It is an injury to the muscle within a compartment which causes swelling and compresses neurovascular bundles

Question 15

Explain the function of deep fascia in the arm

Answer 15

The lateral and medial intermuscular septae divides the arm into a flexor and extensorc compartment

Question 16

Explain the function of deep fascia in the forearm

Answer 16

The antebracial fossa forms the interosseous membrane that seperates anterior and posterior compartments.

Question 17

Explain the function of deep fascia in the thigh

Answer 17

The deep facsia in the thigh is also called the facsia lata and is very thick. This facsia then thickens and forms the illiotibial tract which divides the thigh into the anterior (extensor) medial (adductor) and posterior (flexor) compartments

Question 18

Explain the function of deep fascia in the leg

Answer 18

The fascia lata becomes the crural facsia which divides into the anterior, 2 posterior and lateral compartments. The interosseous membrane is also formed

Question 19

What compartment of the leg is most susceptible to compartment syndrome?

Answer 19

The anterior compartment

Question 20

What is a dermatome and myotome?

Answer 20

Dermatome: A strip of skin supplied by 1 spinal nerve
Myotome: Muscle or group of skeletal muscles supplied by 1 spinal nerve

Question 21

What ramus doesn’t for plexuses?

Answer 21

Dorsal rami

Question 22

Describe the intracasies from the grey matter to plexuses

Answer 22

originates from the grey matter of the spinal cord. The ventral (motor) roots come out the ventral horn. The dorsal roots (sensory) come out the dorsal horn. Before the spinal nerve, the doral root ganglion is there. At the pinal nerve, the ventral roots become the sympathetic ganglion. After the spinal nerve becomes the dorsal and ventral rami and branches where motor+ sensory neurons are mixed together