Exam 4 HELP ME

What are the 4 main functions of the muscular system?

Movement, posture, joint stability, and heat production.

How much of body mass is muscle?

About 1/3 to 1/2.

What controls skeletal muscles?

The central nervous system.

What is a muscle?

An organ made of two or more tissues.

What are the functions of muscle connective tissue?

Protection, attachment, and pathways for blood vessels and nerves.

What are the three muscle connective tissue layers?

Epimysium, perimysium, and endomysium.

What is epimysium?

Connective tissue surrounding the entire muscle.

What is perimysium?

Connective tissue surrounding a fascicle.

What is endomysium?

Connective tissue surrounding an individual muscle fiber.

What is fascia?

Connective tissue connecting muscles to skin or other muscles.

What is a tendon?

Connective tissue connecting muscle to bone.

What happens to the three mysium layers at a tendon?

They merge together.

What is a fascicle?

A bundle of muscle fibers.

What is a muscle fiber?

An individual muscle cell.

What is the order of muscle organization?

Muscle → fascicle → muscle fiber.

What does excitability mean?

Ability to respond to a stimulus.

What does contractility mean?

Ability to shorten and generate force.

What does elasticity mean?

Ability to return to normal shape.

What does distensibility mean?

Ability to stretch.

What does conductivity mean?

Ability to carry electrical signals along the membrane.

What is an action?

Body movement caused by muscle contraction.

What does innervate mean?

To supply a structure with nerves.

What is a muscle's origin?

The relatively stationary attachment point.

What is a muscle's insertion?

The attachment point that moves during contraction.

What is an agonist?

The main muscle producing a movement.

What is another name for an agonist?

Prime mover.

What is an antagonist?

A muscle that opposes the agonist.

What is a synergist?

A muscle that assists and guides movement.

What is a fixator?

A muscle that stabilizes a bone during movement.

What is an antagonistic pair?

Two muscles that perform opposite actions.

What does an abductor do?

Moves a body part away from the midline.

What does an adductor do?

Moves a body part toward the midline.

What does a flexor do?

Decreases the angle between bones.

What does an extensor do?

Increases the angle between bones.

What does a levator do?

Raises a body part.

What does a depressor do?

Lowers a body part.

What does a pronator do?

Turns the palm posteriorly.

What does a supinator do?

Turns the palm anteriorly.

What does an erector do?

Holds a body part upright.

What can muscle names describe?

Action, shape, location, size, fiber direction, or number of heads.

What does triceps mean?

Three heads.

What does major mean in a muscle name?

Large.

What is gliding?

One flat bone surface slides over another.

What is angular movement?

Movement that changes the angle between bones.

What is rotational movement?

A bone rotates around its own axis.

What are special movements?

Movements unique to certain joints.

What is flexion?

Decreases the angle between bones.

What is extension?

Increases the angle between bones.

What is hyperextension?

Extending beyond the anatomical position.

What is lateral flexion?

Bending the neck or trunk sideways.

What is abduction?

Moving away from the body's midline.

What is adduction?

Moving toward the body's midline.

What is circumduction?

Circular movement combining several angular movements.

What is medial rotation?

Rotating toward the body's midline.

What is lateral rotation?

Rotating away from the body's midline.

What is pronation?

Turning the palm posteriorly or downward.

What is supination?

Turning the palm anteriorly or upward.

What is depression?

Moving a body part downward.

What is elevation?

Moving a body part upward.

What is protraction?

Moving a body part forward.

What is retraction?

Moving a body part backward.

What is inversion?

Turning the sole of the foot inward.

What is eversion?

Turning the sole of the foot outward.

What is opposition?

Moving the thumb to touch a fingertip.

What is reposition?

Returning the thumb to its anatomical position.

What is dorsiflexion?

Pointing the toes upward.

What is plantarflexion?

Pointing the toes downward.

What is the origin of the sternocleidomastoid?

Manubrium of sternum and medial portion of clavicle.

What is the insertion of the sternocleidomastoid?

Mastoid process of temporal bone.

What does the sternocleidomastoid do?

Together: flexes head; individually: flexes and rotates head toward opposite side; accessory muscle of inspiration.

What is the origin of the trapezius?

External occipital protuberance, cervical vertebra, and spinous processes of thoracic vertebra.

What is the insertion of the trapezius?

Lateral clavicle, spine, and acromion of scapula.

What does the trapezius do?

Elevates the scapula; also assists with scapular movement.

What is the origin of the rectus abdominis?

Superior aspect of pubic bones.

What is the insertion of the rectus abdominis?

Costal cartilages of inferior ribs.

What does the rectus abdominis do?

Flexes the trunk and compresses the abdominal cavity.

What is the origin of the pectoralis major?

Medial clavicle, sternum, and costal cartilages 1–7.

What is the insertion of the pectoralis major?

Greater tubercle and lateral lip of intertubercle sulcus of humerus.

What does the pectoralis major do?

Flexes and adducts the arm; rotates the arm medially.

What is the origin of the deltoid?

Acromion and spine of scapula; lateral clavicle.

What is the insertion of the deltoid?

Deltoid tuberosity of humerus.

What does the deltoid do?

Abducts the arm; secondarily flexes and extends the arm.

What is the origin of the biceps brachii?

Supraglenoid tubercle and coracoid process of scapula.

What is the insertion of the biceps brachii?

Radial tuberosity of radius.

What does the biceps brachii do?

Flexes the forearm and supinates the forearm.

What is the insertion of the triceps brachii?

Olecranon process of ulna.

What does the triceps brachii do?

Extends the forearm.

What is the origin of the gluteus maximus?

Posterior and lateral portions of ilium, sacrum, and coccyx.

What is the insertion of the gluteus maximus?

Gluteal tuberosity of femur.

What does the gluteus maximus do?

Rotates thigh laterally, abducts thigh, and extends thigh.

What is the origin of the adductor longus?

Body of pubis.

What is the insertion of the adductor longus?

Linea aspera of femur.

What does the adductor longus do?

Adducts thigh, flexes thigh, and rotates thigh medially.

What is the origin of the gastrocnemius?

Medial and lateral condyles of femur.

What is the insertion of the gastrocnemius?

Posterior calcaneus.

What does the gastrocnemius do?

Plantarflexes the foot and flexes the leg.

What is the origin of the tibialis anterior?

Lateral condyle of femur primarily.

What is the insertion of the tibialis anterior?

Tarsal and first metatarsal.

What does the tibialis anterior do?

Dorsiflexes and inverts the foot.

What is the origin of the rectus femoris?

Anterior inferior iliac spine and superior margin of acetabulum.