Ch. 10 study qs

Brian decided to enter a 5 mile race designed to raise money for a class trip. He did not do any preconditioning, nor has he ever jogged before. The morning after the race, Brian had so much pain in both his legs, he was unable to go to school. What caused this pain?

Brian was not conditioned for this type of run, and he now has shin splints. This is a condition in which the anterior tibialis muscle is irritated, and as the inflamed muscle swells, its circulation is impaired by the tight fascia! wrappings, causing pain and tenderness.

An elderly woman, with extensive osteoarthritis of her left hip joint, entered the hospital to have a total hip joint replacement (prosthesis implantation). After surgery, her left hip had to be maintained in adduction to prevent dislocation of the prosthesis while healing was occurring. Physical therapy was prescribed to prevent atrophy of the gluteal muscles during the interval of disuse. Name the gluteal muscles and describe the action of each that was being prevented while the hip was adducted.

Gluteus maxim us, gluteus medius, and gluteus minimus. These muscles originate on the pelvis; they act as major e,ctensors of the thigh and abduct and rotate the thigh as well.

Malcolm was bending over to pick up a heavy box when he was suddenly startled by a rat. He experienced severe pain in his back with muscle spasms and was unable to straighten up. What muscles could have been affected?

He probably affected the erector spinae muscles, since these readily go into spasms when the back is injured.

Muscles that act as synergists seem to have valuable functions, especially in stabilizing joints. Briefly explain their function.

Synergists aid agonists by promoting the same movement or by reducing undesirable or unnecessary movements that might occur as the prime mover contracts.

Which muscle is used for normaI breathing and which additional muscles are used when performing strenuous exercises?

The diaphragm is the primary breathing muscle. The external intercostals are used to increase inspiration and are synergistic to the diaphragm. Forced exhalations use the internal intercostals

In emphysema, the lungs become overdistended with trapped air. Effective abdominal breathing is decreased. Describe the muscles involved when breathing becomes an active process, such as a patient who has emphysema.

The internal intercostal muscles form the deeper layer of the thorax and aid active (forced) expiration by depressing the rib cage.

A wide receiver for the Dallas Cowboys pulled a hamstring muscle. What muscles could be affected and what would the effect be?

The muscles include the biceps femoris, semitendinosus, and semimembranosus. They are important flexors of the leg and extensors of the thigh. lnjuries here could make it impossible to run properly or to bend the thigh.

A woman mentions to her friend that another person on the beach has "great abs." What is she talking about?

The woman is referring to well-developed rectus abdominis muscles on some individual. This is a term coined by bodybuilders and refers to the bulging muscles between the tendinous intersections.

Bodybuilders are known for their "great quads." Describe the quadriceps muscles.

These are the muscles of the front and sides of the thigh, and include the rectus femoris and the lateral, medial, and intermediate vastus muscles.

How does an antagonist differ from a prime mover? How is it the same?

A prime mover is the muscle that causes the desired movement to occur. An antagonist is a muscle that opposes the action of the prime mover in a given movement. If, however, the direction of movement reverses, the former antagonist is now the prime mover and the former prime mover is now the antagonist.

What is a fascicle? What is the result of different fascicle arrangements? List the seven different fascicle arrangements of human skeletal muscles and give a specific example of each.

Muscle cells are called muscle fibers. A bundle of muscle fibers is called a fascicle. A fascicle is surrounded by a connective tissue sheath called the perimysium. Fascicle arrangements produce skeletal muscles with different structures and functional properties, and determine their individual range of motion and power. 1. Circular-orbicularis oris,orbicularis oculi 2. Convergent-pectoralis major 3. Parallel-sartorius 4. Fusiform-biceps brachii 5. Unipennate-extensor digitorum longus 6. Bipennate-rectus femoris 7. Multipennate-deltoid

list the seven criteria that are used in naming muscles and give an example of each.

Muscles have many shapes & sizes . They are named on the basis of several criteria. l. Direction of the muscle fibers (e.g.,external oblique) 2. Relative size of the muscle (e.g.,maximus, minimus,longus) 3. Location of the muscle (e.g.,temporalis,frontalis) 4. Number of origins (e.g.,biceps, triceps, quadriceps) 5. Location of the muscle's origin and insertion (e.g.,the sternocleidomastoid muscle has its origin on the sternum [sterno] and clavicle [cleido] and inserts on the mastoid process of the temporal bone) 6. Shape of the muscle (e.g.,the deltoid muscle is roughly triangular - deltoid means "triangular") 7. Action of the muscle (e.g.,the adductor muscles of the thigh all bring about its adduction, and the extensor muscles of the wrist all extend the wrist)

list the "five golden rules" of gross skeletal muscle activity.

l. With few exceptions, all muscles cross at least one joint. 2. Typically, the bulk of the muscle lies proximal to the joint crossed. 3. All muscles have at least two attachments: the origin and the insertion. 4. Muscles can only pull: they never push. 5. During contraction, the muscle insertion moves toward the origin.