A&P Chapter 10

The gastrocnemius muscle of the calf causes plantar flexion when it contracts. The joint works as a second-class lever. This is useful because second-class levers

exert more force than other types of levers

The biceps brachii acts as a third-class lever, pulling on the radius to move the hand a long distance compared to how far the muscle shortens. To get the most distance for its force, which type of fascicle organization would the biceps brachii have?

parallel

The quadriceps muscle group, the knee extensors, consists primarily of pennate muscles. What advantage does this arrangement provide?

increased force

The buccinator muscle is innervated by the

facial nerve

At its insertion (unlike at its origin), the buccinator muscle

attaches to fibers of another facial muscle

The buccinator muscle

compresses the cheeks

The temporalis muscle originates on the __________ and inserts on the

temporal fossa; coronoid process of mandible

The temporalis muscle is innervated by the mandibular branch of the __

trigeminal nerve

The masseter muscle originates on the

medial surfaces of the maxilla and the zygomatic arch as well as the inferior border of the zygomatic arch

The masseter is innervated by the _____________ branch of the trigeminal nerve.

mandibular

Acting bilaterally, the splenius capitis

extends the head

The insertions of the semispinatus capitus are on the

occipital bone

The fibers of the iliocostalis muscle are divided into which three regions?

lumbar, thoracic, and cervical

The entire length of longissimus muscle extends from the mastoid process of the temporal bone to the

sacrum

The least variable of the different parts of the spinalis muscle is the __

spinalis thoracis

The actions of the internal obliques include __________.

compression of the abdomen to assist in forced expiration

The actions of the internal intercostals are most important during __________.

forced expiration

The origin of the external obliques includes ribs __________.

five through twelve

The origins of the rectus abdominus muscle are on the __________.

public bone

The external intercostals elevate the rib cage during __________.

inspiration

The transversus abdominus muscle is innervated by the __________.

intercostals nerves

The two heads of the biceps brachii combine to insert on the __________.

radial tuberosity

The brachialis muscle is located __________ to the biceps brachii muscle.

deep

All fibers of the triceps brachii are innervated by the __________.

radial nerve

The deltoid muscle fibers are separated into __________.

anterior, middle, and posterior

The middle fibers of the deltoid muscle __________.

abduct the arm

The tensor fasciae latae stabilizes the hip joint and the __________ joint.

knee

Both the Psoas major muscle and iliacus muscle insert on the __________.

lesser trochanter of the femur

The origin of the Sartorius muscle is from the __________ spine.

anterior superior iliac

The majority of the fibers of the gluteus maximus insert onto the __________.

ileotibial tract

The gluteus maximus is the most powerful muscle during __________.

extension

The gluteus medius muscle is innervated by the __________.

superior gluteal nerve

Which joint is considered the most flexible joint in the body?

shoulder

Muscles of the shoulder can be divided into groups based on __________.

distibution and functional relationship

Which of the following groups of muscles are not muscles of the shoulder?

the anterior flexor muscles

The pectoral girdle consists of the __________.

clavicle and scapula

The primary function of the pectoral girdle is to __________.

act as an attachment site for muscles that move the arm

The rhomboideus minor muscle originates on which process on the vertebrae?

spinous process

The four muscles that comprise the posterior group of the pectoral girdle are the __________.

levator scapulae, rhomboideus minor, rhomboideus major, and trapezius

The trapezius muscle may be separated into all of the following groups, except __________.

lateral

All fibers of the trapezius muscle are innervated by the __________.

spinal accessory nerve

The rhomboid minor muscle sits __________.

superior to the rhomboid major

The actions of the rhomboid major on the scapula do not include __________.

lateral rotation

The origin of the serratus anterior includes __________ ribs.

eight , 8

The rotator cuff is a term used to describe the group of muscles and tendons that stabilize and reinforce the __________.

glenohumerral joint

All the tendons of the rotator cuff muscles combine at which location?

humeral head

A reduction in the lateral angle of the glenohumeral joint in relation to the anatomical position would be called __________.

adduction

Movement of the shoulder laterally away from the body is called __________.

abduction

The insertion of the supraspinatus muscle is on the __________.

greater tubercle of the humerus

The infraspinatus inserts on the ____________ of the humerus.

greater tubercle of the humerus

The infraspinatus muscle is included in the __________ muscles.

rotator cuff

The latissimus dorsi inserts __________.

on the intertubercular groove of the humerus

One of the actions of the latissimus dorsi muscle is to __________.

adduct the arm

The subscapularis muscle inserts on the __________.

lesser tubercle of the humerus

The insertion of the teres minor is on the __________.

greater tubercle of the humerus

The teres major adducts the arm but does not __________ the arm.

abduct

The pectoralis minor muscle is innervated by the __________.

pectoral nerves

Movement of the elbow joint movement is limited to __________.

flexion and extension

Movement of the forearm includes __________.

pronation and supination

Why are the muscles that move the fingers and wrist located in the forearm?

This design allows the hand to maintain fine motor control and strength without the interference of bulky muscles.

The forearm muscles can be divided into anterior flexors and posterior extensors, as well as __________.

deep and superficial layers

To allow movement of the tendons within the carpal tunnel zone, each tendon is encased in a __________.

sheath

Carpal tunnel syndrome is characterized by __________.

inflammation of the flexor retinaculum and/or tendon sheaths

Of all the flexor muscles of the forearm, the __________ is the shortest.

pronator teres

The brachioradialis is a strong forearm __________.

flexor

At the completion of supinator action, the palm is turned __________.

anteriorly

The actions of the muscles that cross the hip do not include __________.

inversion

Muscles that act on the knee joint form most of the mass of the __________.

thigh

The origin of the rectus femoris is the ____________.

anterior inferior iliac spine

The rectus femoris muscle extends the leg at the __________.

knee

All fibers of the semimembranosus muscle converge to insert on the __________.

posterior tibia

The semimembranosus __________ the thigh at the hip and __________ the leg at the knee.

extends; flexes

The vastus lateralis is innervated by the __________.

femoral nerve

The semitendinosus muscle lies ______________ to the semimembranosus muscle.

posterior

The semitendinosus muscle is innervated by the __________ nerve.

tibial portion of the sciatic

Both heads of the biceps femoris muscle __________.

flex the leg at the knee

The biceps femoris is located in the __________.

posterior thigh

The long head of the biceps femoris muscle originates on the __________.

ischial tuberosity

Which of the following is not true of the deep fascia of the leg?

an insertion for the majority of lower leg muscles

The origins of the lateral head of the gastrocnemius muscle are the __________.

lateral condyle and posterior surface of the femur

The gastrocnemius muscle is innervated by the __________.

tibial nerve

The two heads of the gastrocnemius muscle converge to insert onto __________.

the calcaneus

The tibialis anterior muscle dorsiflexes the foot at the ankle and also assists in __________ of the foot.

inversion

The tibialis posterior muscle originates at which three locations?

tibia, patellar surface, and interossecous membrane

The soleus muscle shares an insertion with the __________.

gastrocnemius muscle

The soleus muscle __________ the foot at the ankle and is innervated by the __________.

flexes; tibial nerve