Exam 2 Applied Kinesiology Ch 7-11

Question 1

What are the 3 types of muscle tissue

Answer 1

Cardiac, smooth, skeletal m.

Question 2

Cardiac muscle (description, action, location)

Answer 2

Description: striations, branched, 1 nucleus per-cell, intercalated disks.

Action: involuntary, expands, and contracts. (the heart expands and contracts when we are healthy, but as we grow old the heart’s aorta does not have that much expansion and contraction leading to heart disease)

Location: only found in the walls of the heart.

Question 3

Smooth muscle (description, action, and location)

Answer 3

Description: spindle shape, no striations, single nucleus per-cell, contains a cell membrane.

Action: involuntary meaning it moves on its own, and can function without any nerve impulse. (peristalsis such as moving food down)

Location: found in the walls of the hollow organs (such as the intestines, urinary bladder, BV, and uterus)

Question 4

Skeletal muscle (description, action, and location)

Answer 4

Description: striations, multi-nucleated, contains myofilaments (actin and myosin), long, cylindrical, and parallel.

Action: voluntary meaning we can control them. It moves the bones by being attached by a tendon. Used for movement, posture/position, soft tissue support, protection, maintaining body temp, nutrient storage.

Location: found in the bones (attached to the bones via a tendon)

Question 5

What is a myofascial unit?

Answer 5

Contains highly organized muscle cells. Tendons are the continuation of the fascia. Contains the muscle fibers and fascia.

Question 6

What is a muscle fiber?

Answer 6

Contains also the fascia profundus a deep fascia that fills the muscle which allows the muscle to move (lymph (WBC’s), capillaries). Contains the epimysium (surrounds the whole muscle), perimysium (surrounds the bundles of fascicles), endomysium (surrounds 1 muscle fiber), and fascicles are the bundles of muscle fibers (becoming 1 strand).

Question 7

What is a myofibrils?

Answer 7

Are surrounded by the endomysium and contain myofilaments (actin and myosin).

Question 8

What is a myofibrils?

Answer 8

Are surrounded by the endomysium and contain myofilaments (actin and myosin).

Question 9

What is a myofilament?

Answer 9

A myofilament is made up of actin and myosin located in the sarcomere.

Question 10

Sarcolemma vs sarcoplasm

Answer 10

Sarcolemma is a muscle cells membrane. Meaning it is the outside of the myofibrils. It is the shell.

Sarcoplasm is where fluid inside a muscle cell is. Meaning it is the inside of the myofibrils where organelle such as nerves and blood vessels can be found. It contains actin and myosin.

Question 11

What is the muscle belly? How does it work during contraction?

Answer 11

1. Refers to the thickest or largest section of a muscle and is made up of many bundles of muscle fibers called fascicles.
2. The muscle is attached to the tendons and will pull the bones towards the stable joint. So, when a muscle contracts, a tendon is pulled and the bone will pivot around a joint, and this will cause a body part to move. So, with flexion (pull up) we have the humerus moving towards the ulnar so it is the opposite this is Sa close exercise. So, one muscle end is stable and the other is free.

Question 12

3 scenarios can occur with the muscle belly what are they?

Answer 12

Scenario 1: pulling the ultra to the humerus. A bone pulled towards the center of the muscle. (Close chain)

Scenario 2: pulling the humerus to the ulna. A bone (opposite bone) pulled towards the center of the muscles.

Scenario 3: both the ulna and humerus move towards the center. Both bones are moved simultaneously.

Question 13

In muscles contraction what is the origin and insertion?

Answer 13

1. Original = more stable end (proximal attachment, meaning closer to the medial/center), and it will never change even if it is doing the opposite movement. (Proximal - closer to the origin)
2. Insertion = more movable end (distal attachment, meaning father away form the medial/center) (distal- farther from origin)

Question 14

Describe what a sarcomere is and what do they do. (Daw) contains 10 things.

Answer 14

1. Contains think (myosin) and thin (actin) myofilaments
   *think- is the A band (looks dark and thick)
   *thin- is the I band (looks light and thin)
2. Myosin - contains myosin head used to bind to actin
3. Actin - contains tropomyosin and troponin and had myosin binding site.
4. Tropomyosin - is attached to actin and is like a rope that block the myosin head from binding
5. Troponin - is activated when calcium binds to it and changes the configuration of tropomyosin for myosin to bind to actin.
6. Titian - is an elastic band, and holds down the myosin in place.
7. M line - the middle area. The sarcomere and myosin filaments connect and pull each other.
8. H zone - the lightest part and contains no acting and myosin heads.
9. Z line- connects sarcomere to sarcomere and when contraction occurs it will pull towards the M line creating a shortening of the sarcomere.
10. Cross bridge - when myosin and actin pull on one another (power stroke).
11. T-tubules - release calcium for the binding to troponin and used for muscle contraction along with ATP. Are found in the SR (sarcoplasmic reticulum)

Question 15

What are the function of muscle tissue? (4 total) Give examples.

Answer 15

1. Creates movement
2. Stabilize posture - postural muscle contraction and stabilize joints
3. Assist fluid circulation - contraction and relaxation help in moving the fluid: such as lymph (WBC’s), and blood vessels (RBC’s)
4. Thermogenesis - contractions generate heat, shivering when we are cold are tiny muscle contractions

Question 16

What are the prosperity of muscle tissue? (4 total) Explain.

Answer 16

1. Excitability - ability to receive and respond to stimuli from a somatic motor neuron (motor = afferent). (React to a stimulus/input the NS is involved)
2. Contractility - ability to shorten/contract (contraction take place)
3. Extensibility - ability to stretch/extend (stretching is involved)
4. Elasticity - ability to snap back to its original shape and length after a stretch (ability to recoil, spring back, widen and go back to normal.)

Question 17

What is a parallel muscle? Explain structure and function.

Answer 17

They are fibers that run parallel to the length of the muscle.

Structure: long fibers arranged parallel to the length of the muscle.

Function: pulls over a greater ROM known as excursion, has less strength (force)

Question 18

What is a pennate muscle? Explain the structure and function.

Answer 18

They are fibers that run in an angle and are shorter. Have greater cross-sectional area and higher force (power) but shorter ROM (excursion)

Structure: large amounts of short fibers that run oblique (angle) to their central tendon.

Function: can generate a greater strength (force), but have less ROM (excursion)

Question 19

What are the 5 common types of parallel muscle?

Answer 19

1. Flat - frontalis (forehead) it is a muscle that “hugs”
2. Sphincter - circular it can be found in the mouth, eyes, and anus
3. Fusiform - looks like a “turkey leg” and can be found in the biceps brachii
4. Strap - can be found in the Sartorius muscle, Rectus abdominal (abs “6 pack”).
5. Triangular - shape of a “fan” can be found in the pecs major, the trapezius or latismus dorsi muscle.

Question 20

What are the 3 types of pennate muscle?

Answer 20

1. Unipennate - diagonal fibers on one side of a long tendon ex. extensor digitorum longus (found in the lateral, lower leg.)
2. Bipennate - feather like angled design coming off both sides of a central tendon ex. Rectus femoris of the thigh (crosses the hip joint)
3. Multipennate - a grouping of bipennate muscle bellies that form 1 large muscle ex. Deltoid and infraspinatus

Question 21

What is the functional comparison of parallel m. And pennate m.?

Answer 21

1. Parallel - are long muscle fibers, have a higher ROM (excursion), and less strength (force). Ex. Being able to lift a small to medium weight.
2. Pennate - are large amounts of short fibers, have less ROM (excursion), and with a higher cross-sectional area the higher strength (force). Ex. Being able to lift a larger heavier weight.

Question 22

What is a motor unit?

Answer 22

Motor neuron and all the muscle fibers that are acted upon by the motor neuron.

(Motor unit is the motor neuron that innervate the m. and targeted organs.)

Question 23

What occurs for muscle “Programming” (total 3), and what do they do?

Answer 23

1. All or none law - where an impulse reaches threshold for AP to occur Ex. An AP to be sent down an axon or innervation of a targeted m. or organ. (Note: a weak stimulus from the nerve is called subliminal or sub-threshold.)
2. Motor neuron distribution - motor units are spread out through the muscle so you have and even amount of tension thought the muscle belly. (Tension is disperse over a grater area, b/c if they all recruited on one side only one side would be tense and the other would be limp/flabby)
3. Recruitment with wave summation - recruitment is the number of motor units (motor neuron + all innervated muscle fibers) activated. The wave summation is the pace at which nerve signals are firing through a motor unit (recruiting more motor units will cause grater strength. So, the pause of how much strength is being required) Note: all of the motor units don’t fire simultaneously since it will lead to convulsive spasms in the muscle. Needing them to work in an alternating pattern.