chapter 11, muscles Flashcards
What is the origin of a muscle?
The fixed attachment point of a muscle.
What is the insertion of a muscle?
The moveable attachment point of a muscle.
Define action in the context of muscle movements.
The movement produced by a muscle.
What is a prime mover (agonist)?
The main muscle responsible for a movement.
What role does a synergist play in muscle movement?
A muscle that assists the prime mover.
What is the function of an antagonist muscle?
A muscle that opposes the action of the prime mover.
What is a fixator in muscle actions?
A muscle that stabilizes a joint or the origin of a prime mover.
What does flexion mean in muscle movements?
Decreasing the angle between two bones.
What is extension in the context of muscle actions?
Increasing the angle between two bones.
Define abduction.
Moving a limb away from the midline.
What is adduction?
Moving a limb toward the midline.
What does rotation refer to in muscle movements?
Turning a bone around its own axis.
What is circumduction?
Moving a limb in a circular motion.
What does elevation mean in terms of muscle actions?
Raising a body part (e.g., shrugging shoulders).
Define depression in muscle movements.
Lowering a body part.
What is protraction?
Moving a body part forward (e.g., jutting chin forward).
What does retraction mean?
Moving a body part backward.
Define supination.
Rotating the palm upward.
What is pronation?
Rotating the palm downward.
What does dorsiflexion refer to?
Lifting the foot towards the shin.
What is plantar flexion?
Pointing the toes downward.
What does location refer to in muscle naming conventions?
Named for the structure they are near (e.g., temporalis near the temporal bone).
How is muscle shape used in naming conventions?
Named for their shape (e.g., deltoid is triangular).
What size descriptors are used in muscle naming?
Terms like major, minor, maximus, minimus, longus, and brevis.
What does the direction of fibers indicate in muscle naming?
Rectus (straight), transversus (across), oblique (angled).
What does the number of origins refer to in muscle naming?
Biceps (two origins), triceps (three origins), quadriceps (four origins).
What is the significance of action in muscle naming?
Named for their function (e.g., flexor, extensor, abductor).
What do attachment points indicate in muscle naming?
Named for their origin and insertion (e.g., sternocleidomastoid).
What is the function of the frontalis muscle?
Raises eyebrows.
What does the orbicularis oculi muscle do?
Closes eyelids.
What is the action of the orbicularis oris muscle?
Closes and puckers lips.
What is the role of the masseter muscle?
Elevates the mandible (chewing muscle).
What does the temporalis muscle assist with?
Assists masseter in chewing.
What is the function of the sternocleidomastoid muscle?
Rotates and flexes the neck.
What does the pectoralis major muscle do?
Adducts and flexes the humerus.
What is the action of the rectus abdominis muscle?
Flexes the spine.
What does the external oblique muscle do?
Rotates the trunk.
What is the function of the internal oblique muscle?
Works with the external oblique to rotate the trunk.
What does the transversus abdominis muscle do?
Compresses the abdomen.
What is the role of the diaphragm?
Prime mover for respiration.
What do intercostal muscles assist with?
Breathing by expanding the ribcage.
What is the function of the trapezius muscle?
Elevates, retracts, and depresses the scapula.
What does the latissimus dorsi muscle do?
Extends, adducts, and rotates the arm.
What is the role of the erector spinae muscle?
Extends the spine and maintains posture.
What does the deltoid muscle do?
Abducts the arm.
What is the action of the biceps brachii muscle?
Flexes the elbow and supinates the forearm.
What does the triceps brachii muscle do?
Extends the elbow.
What is the role of the brachialis muscle?
Assists the biceps in flexing the elbow.
What does the flexor carpi radialis muscle do?
Flexes the wrist.
What is the action of the flexor carpi ulnaris muscle?
Flexes the wrist.
What does the extensor carpi radialis muscle do?
Extends the wrist.
What is the role of the extensor carpi ulnaris muscle?
Extends the wrist.
What does the gluteus maximus muscle do?
Extends the hip.
What is the action of the gluteus medius muscle?
Abducts the hip.
What does the quadriceps femoris muscle group do?
Extends the knee (includes rectus femoris, vastus lateralis, vastus medialis, and vastus intermedius).
What is the function of the hamstrings?
Flex the knee and extend the hip (includes biceps femoris, semitendinosus, and semimembranosus).
What does the adductor group do?
Adducts the thigh.
What is the action of the tibialis anterior muscle?
Dorsiflexes the foot.
What does the gastrocnemius muscle do?
Plantar flexes the foot (calf muscle).
What is the role of the soleus muscle?
Assists gastrocnemius in plantar flexion.
What do peroneus (fibularis) muscles do?
Evert and plantar flex the foot.
What is tendinitis?
Inflammation of a tendon.
What is carpal tunnel syndrome?
Compression of the median nerve in the wrist.
What is a hernia?
Protrusion of an organ through a muscle wall.
What is a muscle strain?
Overstretching or tearing of muscle fibers.
Define muscle atrophy.
Decrease in muscle mass due to disuse.
What is compartment syndrome?
Increased pressure in a muscle compartment leading to reduced blood flow.
