APE 4: Muscles Flashcards
Is striated muscle voluntary or involuntary?
Striated muscle is voluntary
Is smooth muscle voluntary or involuntary?
Smooth muscle is involuntary
Where does Pectoralis Major originate and insert? What kind of muscle is it?
Pectoralis Major originates at the sternum and inserts at the humerus. It is a convergent muscle because it narrows down from origin to insertion
What is hypertrophy?
The growth of skeletal muscle in response to frequent strenuous exercise, due to muscle fibre enlargement, not addition of new muscle fibres
What is muscle atrophy?
Reduction in size of skeletal muscle due to disuse
Name 2 places where circular muscle can be found
The mouth and the eyes
When a muscle contracts and shortens, one of its attachments usually remains fixed and the other one moves. Which is the origin and which is the insertion?
The origin is usually the proximal end of the muscle, remaining fixed in position during contraction. The insertion is usually the distal end of the muscle, which is movable.
Where is the flexor digitorum superficialis? What’s its function?
The flexor digitorum superficialis is in the anterior forearm, near the surface, and is responsible for the flexion of the wrist and the fingers
Where is the flexor digitorum longus? What’s its function?
The flexor digitorum longus comes past the medial malleolus and down to the plantar surface of the foot. It’s responsible for flexion of the toes
Where is the extensor digitorum? What’s its function?
The extensor digitorum is found in the posterior forearm and is responsible for extension of the fingers
Where is the extensor digitorum longus? What’s its function?
The extensor digitorum longus is found in the dorsal foot and is responsible for extension of the toes
Where is the flexor carpi radialis longus? What’s its function
A relatively thin muscle found in the anterior part of the forearm. Originates at the medial epicondyle of the humerus and runs across the anterior forearm, running just lateral to the flexor digitorum superficialis, and inserts on the anterior aspect of the base of the second metacarpal. The flexor carpi radialis longus is responsible for flexion of the wrist and abduction of the hand.
Where is the tibialis anterior? What’s its function?
Lateral to the tibia at the anterior face. Dorsiflexion and inversion of the foot.
Where is the external oblique abdominis?
In the abdomen. The muscle fibres run in a caudal and medial direction, like putting your hands in your pockets
Where is the orbicularis oculi?
Circular muscle around the eye
Where is the sternocleidomastoid?
One of the largest, most superficial cervical muscles. On both sides of your neck, each muscle runs down the front of the neck and splits to attach to the sternum and clavicle. It originates at the manubrium and the clavicle and has an insertion at the mastoid process of the temporal bone of the skull. Function: rotation of the head and flexion of the neck
Where is the frontalis?
The forehead. Originates at the galea aponeurotica and inserts at the skin around the eyebrows and nose. Raises eyebrows and wrinkles the forehead as it draws the scalp back
Where is the rectus femoris?
The most anterior muscle in the thigh and a part of the quadriceps. The only muscle in the quadriceps group that crosses the hip. Overlies the Vastus intermedius. Responsible for extension of the knee and flexion of the hip. Originates from the AIIS. Bipennate muscle. Inserts at the superior base of the patella
Where is the Brachioradialis?
Originates at the lateral supracondylar ridge of the humerus and inserts at the radial styloid process. Involved in flexion of the elbow, and supination and pronation of the radioulnar joint
Where are the external intercostals?
Originate at the lower border of the ribs and insert at the upper border of the rib. There are 11 on each side. Contract to expand the chest for inhalation. Relax when the thoracic volume decreases for exhalation.
How many muscles are there in the posterior compartment of the arm? What are they?
There’s only 1 muscle in the compartment- the triceps brachii
How many muscles are there in the anterior compartment of the arm? What are their names?
There are 3 muscles in the compartment. The biceps brachii, the coracobrachialis and the brachialis
Where are the seratus anterior muscles found?
Externally either lateral side of the ribcage, anterior to the latissimus dorsi
Where are the triceps surae found?
The triceps surae are in the calf (posterior lower leg)
What are the 2 muscles that make up the triceps surae and how are they connected to the foot?
The two muscles are the gastrocnemius, which is bipennate, and the soleus. The triceps surae are connected to the calcaneous bone of the foot via the Achilles tendon
