ACCURATE ANSWERS
1. Select the option that best describes a characteristic of lumbar vertebrae.
small body
bifid spinous process
Costal facets on transverse processes
large body
2. Describe the role of myosin in the contraction of a muscle fiber.
Myosin attaches to the active site on actin filaments, facilitating
muscle contraction through a sliding mechanism.
Myosin is responsible for the elasticity of the muscle fiber.
Myosin prevents actin from binding during muscle relaxation.
Myosin provides structural support without interacting with actin.
3. What is the origin of the brachioradialis muscle?
ulna near the olecranon
lateral edge of the humerus above the lateral epicondyle
medial epicondyle of the humerus
scapula near the acromion
4. Describe the role of the brachialis muscle in forearm movement.
The brachialis acts as the agonist for flexion of the forearm.
,The brachialis stabilizes the shoulder joint during arm movements.
, The brachialis assists in the rotation of the forearm.
The brachialis extends the forearm at the elbow joint.
5. Describe the primary actions of the rhomboideus major muscle in relation
to the scapula.
The rhomboideus major muscle abducts the shoulder.
The rhomboideus major muscle extends the spine.
The rhomboideus major muscle fixes, retracts, and rotates the
scapula.
The rhomboideus major muscle primarily flexes the elbow.
6. If a bone is subjected to increased mechanical stress, how might the
structure of osteons adapt over time?
Osteons will stop communicating with each other to conserve
energy.
Osteons will decrease in size to reduce weight.
Osteons will lose their lamellae to become more flexible.
Osteons may become denser and more numerous to better
support the increased load.
7. What is the primary action of the iliocostalis muscle?
Flexes the hip
Rotates the spine
Stabilizes the shoulder
Extends and laterally flexes the spine
, 8. Describe the role of canaliculi in the structure of an osteon.
Canaliculi are responsible for the production of new bone cells.
Canaliculi provide structural support to the osteon.
Canaliculi store calcium and phosphate for bone strength.
Canaliculi facilitate communication between lacunae containing
osteocytes.
9. If a patient has an injury to the axillary nerve, what impact would this have
on the teres minor muscle's function?
Impaired lateral rotation of the arm when adducted
Enhanced ability to flex the arm at the elbow
No impact on arm movement
Increased medial rotation of the arm
10. Describe the primary actions performed by the adductor brevis muscle.
The adductor brevis assists in knee extension.
The adductor brevis adducts, medially rotates, and flexes the
thigh.
The adductor brevis stabilizes the pelvis during walking.
The adductor brevis extends and laterally rotates the thigh.
11. If a patient has an injury to the axillary nerve, which muscle's function would
be most affected and what would be the likely consequence?
Pectoralis major; the patient would have difficulty in shoulder
adduction.