10. Muscles

Origin and Insertion

Open Question
What class of lever system do the following activities describe?a. The soleus muscle plantar flexes the foot. b. The triceps brachii is strained while doing pushups.
Open Question
Mary sees Jill coming toward her and immediately contracts her frontalis and procerus. She also contracts her right levator labii. Is Mary glad to see Jill? How can you tell?
Open Question
While unloading her car trunk, Amy strains a muscle and as a result has difficulty moving her arm. The doctor in the emergency room tells her that she strained her pectoralis major. Amy tells you that she thought the pectoralis major was a chest muscle and doesn't understand what that has to do with her arm. What should you tell her?
Open Question
Which eye muscle passes through the trochlea and turns the eye inferiorly and laterally?

a. Lateral rectus muscle
b. Inferior rectus muscle
c. Inferior oblique muscle
d. Superior oblique muscle
Open Question
Mark the following statements as true or false. If the statement is false, correct it to make a true statement.

b. The latissimus dorsi muscle is a major abductor of the arm
Open Question
Which of the following muscles flexes the thigh, but also laterally flexes the vertebral column when its origin and insertion switch?

a. Sartorius muscle
b. Psoas major muscle
c. Iliacus muscle
d. Rectus abdominis muscle
Open Question
Match the muscle with its main action:

____Vastus medius muscle
____Gracilis muscle
____Gluteus medius muscle
____Gastrocnemius muscle
____Biceps femoris muscle
____Tibialis anterior muscle

a. Adducts thigh
b. Extends thigh and flexes leg
c. Plantarflexes foot
d. Abducts thigh
e. Dorsiflexes foot
f. Extends leg
Open Question
Explain how the diaphragm muscle is able to increase the size of the thoracic cavity even though it doesn't insert into a bone.
Open Question
Why do you think that the muscles of the erector spinae and transversospinal muscle groups remain in a state of continual contraction when we are upright?
Open Question
The rectus femoris muscle originates from the anterior superior iliac spine and inserts into the tibial tuberosity. Predict its main actions with only this information.
Open Question
Elise is a competitive gymnast who strained muscles in her left lower limb doing a tumbling pass. She has pain with extension of her leg and inversion of her foot. Which muscles did she potentially strain?
Open Question
Chris is training for his black belt in karate and is working on developing a stronger punch. Which muscles do you recommend that he strengthen to improve his punch? Explain.
Open Question
Ms. Hendrix suffered a severe hip fracture that required hip replacement surgery. After an extended recovery period, she is undergoing physical therapy to regain strength and mobility.

b. Which muscles were likely affected by the hip replacement surgery, and to which parts of the bone do they attach?
Open Question
Ms. Hendrix suffered a severe hip fracture that required hip replacement surgery. After an extended recovery period, she is undergoing physical therapy to regain strength and mobility.

c. Which actions could Ms. Hendrix perform to strengthen these muscles?
Activity
Posterior muscles of the right hip and thigh