Muscular System Practice_week of Nov. 23

Left arm

• Abduction

• Extension

• Supination

• Dorsiflexion

Answer explanation

Abduction means her left arm is lifted laterally away from her body. Extension in seen in her left elbow because it is straight, with no bend in the joint. Supination would require her palm to be up and dorsiflexion is applied to the feet.

Left foot/leg

• Plantar flexion

• Flexion

• Pronation

• Rotation

Answer explanation

Because her left toe in pointed down, it is demonstrating plantar flexion. Her left knee is showing flexion because it is bent. There is no obvious rotation in her leg, since it seems to be facing forward, and pronation is usually applied to the hand/forearm.

Hands

• Opposition

• Flexion

• Pronation

• Adduction

Answer explanation

Opposition is shown by his thumb crossing over his other digits. Flexion is shown in all his fingers being curled towards his palms. Pronation is shown by his palm-down position, causing his forearm bones to be crossed. Adduction is shown because his fingers are pressed together with no space between them.

Left leg/foot

• Rotation

• Dorsiflexion

• Adduction

• Circumduction

Answer explanation

Rotation is shown because her whole leg is turned away from the midline (her knee and toes are not facing forward). Dorsiflexion is seen in her foot, as the heel is down and toes are up. Adduction would require her leg to be moving back towards the midline, which it doesn't seem to be doing. Circumduction would require her leg to be swinging in a circle, which it doesn't seem to be doing.

• Inversion

• Eversion

• Rotation

• Pronation

Answer explanation

Inversion is when the sole of the foot turns inward towards the midline. The circled region is an extreme example. Eversion is the opposite, when the sole turns toward the outside.

Which muscle names are indicating location?

• Occipitofrontalis

• Brachioradialis

• Temporoparientalis

• Tensor fascia lata

Answer explanation

The various locations identified include: occipital, frontal, brachial, radius, temporal, and parietal.

What does this muscle name tell you: PRONATOR QUADRATUS

• Location

• Shape

• Action

• Direction of fibers

Answer explanation

This muscle's action is pronation of the limb and it has the shape of a square (quadrilateral).

What do the TRICEPS BRACHII and the TRICEPS SURAE have in common?

• Location

• Action

• Number of heads

• Shape

Answer explanation

Triceps means having three heads or points of origin. The triceps brachii is in the upper arm but the triceps surae is in the lower calf.

What is different between the PECTORALIS MAJOR and the PECTORALIS MINOR?

• Location

• Action

• Size

• Shape

Answer explanation

Both muscles are in the chest (pectoral region) but one is bigger (major) and one is smaller (minor).

In the muscle name RECTUS CAPITIS ANTERIOR, which word describes the direction of the muscle's fibers?

(a)  

Answer explanation

Rectus is based on the Latin word 'recta' which means 'straight'. It refers to the parallel arrangement of muscle fibers, aligned with the midline.