PA CAT Anatomy

radial nerve innervates

posterior arm and forearm

rotator cuff

supraspinatus, infraspinatus, teres minor, subscapularis

The cord of a plexus is positioned posterior to the second part of the axillary artery. What nerve originates from this cord?

Thoracodorsal nerve The structure is the posterior cord of the brachial plexus. The thoracodorsal nerve originates from this cord. The dorsal scapular nerve originates from the C5 root of the brachial plexus. The long thoracic nerve originates from the anterior rami of C5 to C7. The musculocutaneous nerve originates from the lateral cord of the brachial plexus.

axillary artery branches

"Screw The Lawyer, Save A Patient" -Superior thoracic -Thoracoacromial -Lateral thoracic -Subscapular -Anterior circumflex humeral -Posterior circumflex humeral

An artery supplies the upper regions of the medial and anterior axillary walls. How many branches arise from the part of the axillary artery from which this structure originates?

1 The structure is the superior thoracic artery, which originates from the first part of the axillary artery. The first part of the axillary artery gives rise to one branch. The second part of the axillary artery gives rise to two branches. The third part of the axillary artery gives rise to three branches. In total, six branches arise from the axillary artery.

A muscle within the superficial layer of the posterior forearm is innervated by the radial nerve. QuestionHighlights What is a role of this muscle?

Abductor of the wrist

The muscle lateral to the palmaris longus in the superficial layer of the anterior forearm is innervated by the median nerve. QuestionHighlights What is a function of this muscle?

Abducts the wrist

A muscle in the deep layer of the anterior forearm originates from the anterior and medial surfaces of the ulna. What is another point of origin for this muscle?

Anterior surface of the interosseous membrane The muscle is the flexor digitorum profundus, which originates from the anterior and medial surfaces of the ulna and the anterior surface of the interosseous membrane. This muscle inserts on the distal phalanx of digits 2, 3, 4, and 5. The flexor pollicis longus originates from the anterior surface of the radius. The pronator quadratus originates from a linear ridge located on the anterior surface of the lower end of the ulna.

A structure consists of the pinna and the external acoustic meatus. What feature of this structure introduces delays that generate directional information?

Auricle

An artery passes through the anterior compartment of the arm and terminates distal to the elbow joint. This structure continues from what artery?

Axillary The structure is the brachial artery, a continuation of the axillary artery. The brachial artery divides into the radial and ulnar arteries.

A muscle in the superficial layer of the anterior forearm originates from the medial epicondyle of the humerus and passes to the lateral side of the anterior surface of the wrist. Where does it insert?

Bases of metacarpals II and III The muscle is the flexor carpi radialis, which inserts on the bases of metacarpals II and III. The palmaris longus inserts on the flexor retinaculum. The pronator teres inserts on the lateral surface of the radius. The flexor carpi ulnaris inserts on the pisiform bone of the wrist.

An artery passes through the anterior compartment of the arm and terminates distal to the elbow joint. What vessel is medial to this artery?

Basilic vein The structure is the brachial artery. The basilic vein has a position medial to the brachial artery before becoming the axillary vein. The basilic vein is formed by the radial and ulnar veins.

occipital bone

Bone that protrudes at the base of the skull

A blood vessel passes through the axilla to the inferior margin of the teres major muscle. What is formed by this continuation?

Brachial artery The axillary artery passes through the axilla and becomes the brachial artery at the inferior margin of the teres major muscle. The axillary artery begins at the lateral margin of the first rib and becomes the subclavian artery at the neck. The thoracodorsal artery supplies the latissimus dorsi.

What muscle performs a flexion action despite its location on the posterior forearm?

Brachioradialis Brachioradialis is found on the posterior aspect of the forearm and is an accessory flexor of the elbow. It acts as a flexor despite its location because it lies anterior to the elbow joint. Anconeus is located medial to the superficial extensors. Its main action is abduction of the ulna during pronation, but it also acts as an accessory extensor. Pronator teres is located in the superficial anterior forearm; it rotates the radius over the ulna during pronation. Supinator is found in the deep layer of the posterior forearm; it turns the hand palm up (supination).

A hinge joint with three separate articulations has a shared synovial cavity. One of the three articulations is involved in flexion and extension of the forearm. Question What structure forms an articulation with the head of the radius to enable this movement?

Capitulum of the humerus

A muscle innervated by cranial nerve VII inserts into the skin around the margin of the orbit and the superior and inferior tarsal plates. Question What is a function of this muscle?

Closes the eyelids

A muscle innervated by cranial nerve V originates from the medial surface of the lateral pterygoid plate and inserts into the medial angle of the mandible. QuestionHighlights What is a function of this muscle?

Closes the jaw

The roots and trunks of a plexus enter the posterior triangle of the neck between the anterior scalene and middle scalene. Question What forms the middle trunk of this plexus?

Continuation of the C7 root The structure is the brachial plexus. The middle trunk of the brachial plexus is formed by the continuation of the C7 root. The brachial plexus is formed by the anterior rami of C5 to C8 and most of the anterior ramus ofT1. The superior trunk of the brachial plexus is formed by the union of C5 and C6 roots. The inferior trunk arises from the union of the C8 and T1 roots.

The transition of the neck and the arm is formed by the clavicle, scapula, upper thoracic wall, and humerus with related muscles. This structure contains the proximal portion of what other structure?

Coracobrachialis The axilla contains many structures, including the coracobrachialis. The levator scapulae, rhomboid minor, and trapezius are muscles associated with the shoulder.

A nerve provides the motor innervation to all muscles in the anterior compartment of the arm. QuestionHighlights What muscle does this nerve penetrate to enter the arm?

Coracobrachialis The structure is the musculocutaneous nerve, which enters the arm by penetrating the coracobrachialis. It continues between the biceps brachii and brachialis muscles. The median nerve enters at the margin of the teres major.

A muscle in the intermediate layer of the forearm contains two heads, one of which originates from the medial epicondyle of the humerus. Where is the second origin of this head?

Coronoid process of the ulna The humeroulnar head of the flexor digitorum superficialis originates from the medial epicondyle of the humerus and the medial edge of the coronoid process of the ulna. The radial head of the flexor digitorum superficialis originates from the anterior oblique line of the radius. The flexor digitorum superficialis splits and inserts into the margins of the middle phalanges of digits 2, 3, 4, and 5.

The transition of the neck and the arm is formed by the clavicle, scapula, upper thoracic wall, and humerus with related muscles. How is the apex of the inlet of this structure directed?

Lateral The structure is the axilla. The inlet of the axilla is a triangle with an apex directed laterally. This structure has medial, anterior, and posterior margins formed by the first rib, clavicle, and scapula, respectively.

What is one of the lower muscles of the lips and mouth?

Depressor anguli oris

The part of the axillary artery anterior to the subscapularis muscle and teres major muscle has 3 branches. How is this part oriented in relation to the pectoralis minor?

Distal The structure is the third part of the axillary artery, which is distal to the pectoralis minor. The pectoralis minor crosses anteriorly to the vessel. The first part of the axillary artery is proximal to the pectoralis minor. The second part of the axillary artery is posterior to the pectoralis minor.

A purely efferent accessory nerve is divided into a cranial and spinal portion. What function is modulated by the spinal portion?

Elevation of the scapula The nerve is cranial nerve XI, the spinal accessory nerve. The nerve innervates the sternocleidomastoid and the trapezius. The trapezius elevates the scapula. The hypoglossal nerve is involved in involuntary movements like the clearing of saliva from the mouth. The glossopharyngeal nerve modulates the gag reflex. Outward eye movement is modulated by the abducens nerve.

A muscle in the posterior compartment of the arm is innervated by the radial nerve. What movement does this structure enable?

Extension of the elbow The triceps brachii enables extension of the elbow. The brachialis muscle enables flexion of the elbow. The pronator teres enables pronation of the forearm. The biceps brachii enables supination of the forearm when the elbow joint is flexed.

What is a deep muscle of the posterior forearm?

Extensor pollicus brevis Extensor pollicus brevis is a deep muscle of the posterior forearm that extends the metacarpophalangeal and carpometacarpal joint of the thumb. Extensor digitorum, extensor carpi radialis brevis, and extensor digiti minimi are superficial muscles of the posterior forearm.

What muscle forms the medial border of the anatomical snuffbox?

Extensor pollicus longus Extensor pollicus longus extends all joints of the thumb and forms the medial border of the anatomical snuffbox. Abductor pollicus longus and extensor pollicus brevis make up the lateral border of the anatomical snuffbox. Flexor pollicus longus is found on the anterior aspect of the forearm and does not make a border with the anatomical snuffbox, as this structure is on the posterior aspect of the forearm.

A group of muscles in the superficial layer of the forearm enables flexion of the wrist and fingers and pronation of the hand. Question Which of the muscles in the group is most medial?

Flexor carpi ulnaris

A patient diagnosed as having rotator cuff syndrome demonstrates impingement involving the supraspinatus muscle. What anatomical feature's failure typically causes this injury?

Failure of the subacromial bursa to protect the muscles of the rotator cuff is a typical cause of impingement involving the supraspinatus. The biceps brachii, joint capsule, and musculotendinous collar are sources of stability for the glenohumeral joint, but they are not typical causes of impingement involving the supraspinatus.

Flexion of the four digits involves the metacarpophalangeal joints and the distal interphalangeal joints. QuestionHighlights What muscle facilitates this movement?

Flexor digitorum profundus The flexor digitorum profundus facilitates flexion of the four digits for the metacarpophalangeal and distal interphalangeal joints. The flexor carpi ulnaris facilitates adduction of the wrist. The flexor digitorum superficialis facilitates flexion of the four digits for the metacarpophalangeal and proximal interphalangeal joints. The flexor pollicis longus facilitates flexion of the thumb.

A muscle in the intermediate layer of the forearm splits into two parts near the proximal phalanx of each finger. What other muscle's tendon does this structure pass around posteriorly?

Flexor digitorum profundus The flexor digitorum superficialis splits into two parts and passes around the tendons of the flexor digitorum profundus. The flexor pollicis longus and pronator quadratus are located in the deep layer of the forearm but are not involved with pattern of insertion.

A 58-year-old man cannot actively extend his left ring finger. On exam, his ring finger is flexed at the level of the metacarpophalangeal joint and proximal interphalangeal joint. What tendon is malfunctioning?

Flexor digitorum superficialis Flexor digitorum superficialis is located in the intermediate layer of the anterior forearm and is responsible for flexion of the metacarpophalangeal joint and the proximal interphalangeal joint. Flexor carpi radialis flexes and abducts the wrist and has no action on the fingers. Flexor pollicus longus is a tendon that is a flexor of the thumb. Palmaris longus is an accessory flexor of the wrist and does not perform any flexion of the digits.

A muscle overlies the anterolateral surface of the forearm, forms the lateral boundary of the cubital fossa, and is innervated by the radial nerve. QuestionHighlights What is a role of this muscle?

Flexor of the elbow

A 26-year-old man is seen in the ED after cutting his wrist while opening a package with a knife. Upon examination, he cannot flex his thumb. What structure was injured?

Flexor pollicus longus Flexor pollicus longus is a deep muscle of the anterior forearm that crosses under the carpal tunnel and allows for flexion of the thumb. Flexor carpi radialis is a superficial anterior forearm muscle that flexes and abducts the wrist. Flexor digitorum profundus is a deep muscle of the anterior forearm that passes through the carpal tunnel, but it gives rise to four tendons of the four fingers and allows flexion at the proximal interphalangeal joint, distal interphalangeal joint, and the metacarpophalangeal joint. Flexor digitorum superficialis is an intermediate muscle of the anterior forearm that passes through the carpal tunnel and allows for flexion of the proximal interphalangeal joint and metacarpophalangeal joint of the four fingers.

A fossa is composed of the occipital and temporal bones. What does this structure contain?

Foramen magnum

The meningeal branch of cranial nerve V passes through the middle cranial fossa. What provides passage of this structure?

Foramen spinosum The foramen spinosum is home to the middle meningeal artery, the middle meningeal vein, and the meningeal branch of the trigeminal nerve. The foramen lacerum is home to the greater petrosal nerve. The foramen rotundum is home to the maxillary division of the trigeminal nerve. The foramen ovale is home to the mandibular division of the trigeminal nerve and the lesser petrosal nerve.

The largest cranial nerve contains three divisions that leave the skull through separate foramina; one exits through the superior orbital fissure. QuestionHighlights Which nerve of this branch is the largest?

Frontal

A patient presents with a disorder of the palpebral portion of the orbicularis oculi muscle. What action will they have difficulty performing?

Gentle eye closure

A bone is held firmly in position by the muscles of the rotator cuff. QuestionHighlights What does the head of this structure articulate with?

Glenoid cavity of the scapula

An intermuscular septum divides the arm into anterior and posterior compartments and extends to the outer sleeve of deep fascia surrounding the arm. From what bone does this structure extend?

Humerus The intermuscular septum of the arm extends from the humerus to the outer sleeve of deep fascia surrounding the arm. The acromion is located in the shoulder. The radius and ulna are located in the forearm.

Landmarks on the proximal end of the humerus are separated by an intertubercular sulcus. QuestionHighlights In what direction does this groove continue?

Inferior

A muscle innervated by the radial nerve enables extension of the forearm at the elbow joint. Where does the long head of this muscle originate?

Infraglenoid tubercle of the scapula The long head of the triceps brachii originates from the infraglenoid tubercle of the scapula. The medial head of the triceps brachii originates on the posterior surface of the shaft of the humerus, inferior to the radial groove. The lateral head of the triceps brachii originates superior to the radial groove of the humerus.

Joints in the upper limb, including the wrist and digits, display actions powered by flexor muscles. Which of them facilitates flexion and extension as main mechanisms of movement?

Interphalangeal joint The interphalangeal joints generally facilitate flexion and extension as main movements. The carpometacarpal joints (except the thumb) facilitate limited gliding movements. The metacarpophalangeal joints facilitate flexion, extension, abduction, adduction, circumduction, and limited rotation. The wrist joint facilitates abduction, adduction, flexion, and extension.

The middle-glossopharyngeal nerve passes through the posterior cranial fossa. What provides passage of this structure?

Jugular foramen

A muscle in the superficial layer of the anterior forearm originates from the medial epicondyle and supracondylar ridge of the humerus. Question Where does it insert?

Lateral surface of the radius The muscle is the pronator teres, which inserts on the lateral surface of the radius. The flexor carpi radialis inserts on the bases of metacarpals II and III. The palmaris longus inserts on the flexor retinaculum. The flexor carpi ulnaris inserts on the pisiform bone of the wrist.

A cranial nerve is responsible for transmission of signals generated by photoreceptor cells in the retina. What is a general function of this nerve?

Light reflex

An adult demonstrates slight extension of the cervical and lumbar spine. What condition in these regions of the spine is likely?

Lordosis Lordosis of the lumbar and cervical region is typical of a healthy spine. Hyperlordosis is characterized by excessive posterior rounding of the lumbar spine. Spinal stenosis is characterized by a narrowing of the central spinal canal. Spondylolisthesis occurs when a complete dislocation one vertebra occurs, displacing the vertebrae below.

A structure forms the central axis of bearing weight. Which region of this structure is subjected to forces that may cause anterior spondylolisthesis?

Lumbosacral The lumbosacral region may demonstrate impairments such as anterior spondylolisthesis or partial dislocation of the sacroiliac joints. This region is typically subject to larger forces than the cervicothoracic, craniocervical, and thoracolumbar regions due to weight transfer from the body through the pelvis to the lower extremities.

A structure contains ossicles connected to the tympanic membrane. What serves as the primary connection?

Malleus The malleus is directly connected to the tympanic membrane. The malleus then articulates with the incus, which articulates with the stapes. The umbo is a depression of the eardrum located near the handle of the malleus.

The transition of the neck and the arm is formed by the clavicle, scapula, upper thoracic wall, and humerus with related muscles. Question Which wall of this structure is formed by the upper thoracic wall and the serratus anterior muscle?

Medial

A cranial nerve with both sensory and motor components sends the sensation of taste from the anterior portion of the tongue. What muscle group does this nerve innervate?

Muscles of facial expression The nerve is cranial nerve VII, the facial nerve. The facial nerve innervates the muscles of facial expression, among other structures. The trigeminal nerve innervates the muscles of mastication. The muscles of the pharynx are innervated by the glossopharyngeal nerve. The muscles of phonation are innervated by the vagus nerve.

The cord of a plexus is positioned lateral to the second part of the axillary artery. Question What nerve originates from this cord?

Musculocutaneous nerve

A muscle extends from the coracoid process of the scapula to the midshaft of the humerus. Which nerve innervates this muscle?

Musculocutaneous nerve The muscle is the coracobrachialis, which is innervated by the musculocutaneous nerve. Muscles in the forearm are innervated by the median nerve. The triceps brachii muscle is innervated by the radial nerve. Muscles in the hands and forearms are innervated by the ulnar nerve.

Cartilaginous structures between adjacent vertebrae enable motion of the spine and protection from heavy loads. Which component of these structures is composed of loose collagen fibers, water, and proteins?

Nucleus pulposus Intervertebral discs are composed of annulus fibrosus (the outer portion) and nucleus pulposus (inner gel). Nucleus pulposus is composed of loose collagen fibers, water, and proteins. Lordosis is the convex curvature of the cervical and the lumbar regions of the vertebral column. Kyphosis is the concave forward curvature of the thoracic region of the vertebral column.

A purely afferent cranial nerve is responsible for hearing, balance, and body position. What can result from damage to this nerve?

Nystagmus The nerve is cranial nerve VIII, the vestibulocochlear nerve. Pathology involving the vestibular aspect includes vertigo, loss of equilibrium, and nystagmus. Damage to the glossopharyngeal nerve can lead to an absence of the gag reflex. Damage to the olfactory nerve can cause parosmia (a distorted sense of smell). Damage to the facial nerve can lead to Bell's palsy, a condition of temporary facial paralysis.

A muscle in the deep layer of the anterior forearm originates from the anterior surfaces of the radius and interosseous membrane. Where does it insert?

Palmar surface of the distal phalanx The muscle is the flexor pollicis longus, which inserts on the palmar surface of the distal phalanx after passing through the carpal tunnel. The flexor digitorum profundus inserts on the distal phalanx of digits 2, 3, 4, and 5. The pronator quadratus inserts on the anterior flat surface of the radius.

A fossa is composed of the sphenoid bone and the temporal bones. What borders this structure laterally?

Parietals

Five vertebrae compose a region of the vertebral column. What aspect of these structures is directed backward and is oval-shaped?

Pedicle The structure is a lumbar vertebra. The pedicle of lumbar vertebrae is oval-shaped and is directed backward. Foramen in the lumbar vertebrae are triangular in shape. The spinous process of a typical lumbar vertebra is quadrilateral in shape. Transverse processes of lumbar vertebrae project laterally.

The part of the axillary artery that provides the thoracoacromial trunk and the lateral thoracic artery begins at the upper border of the pectoralis minor and ends at the lower border. Question How is this part oriented in relation to the pectoralis minor?

Posterior

The transition of the neck and the arm is formed by the clavicle, scapula, upper thoracic wall, and humerus with related muscles. Which wall of this structure is formed by the scapula, subscapularis, latissimus dorsi, teres major, and the triceps brachii?

Posterior The posterior wall of the axilla is formed by the scapula, subscapularis, latissimus dorsi, teres major, and the triceps brachii. The anterior wall is formed by the pectoralis major, pectoralis minor, and subclavius muscles. The lateral wall is formed by the intertubercular sulcus of the humerus. The medial wall is formed by the upper thoracic wall and the serratus anterior muscle.

A nerve innervates the skin on the lower lateral surface of the arm and the dorsal lateral surface of the hand. This nerve is the largest terminal branch of what formation?

Posterior cord of the brachial plexus The structure is the radial nerve, which is a branch of the posterior cord of the brachial plexus. The long thoracic nerve originates from the anterior rami of C5 to C7. The dorsal scapular nerve originates from the C5 root of the brachial plexus. The lateral pectoral nerve, musculocutaneous nerve, and lateral root of the median nerve originate from the lateral cord of the brachial plexus.

The largest cranial nerve contains three divisions that leave the skull through separate foramina; one exits through the foramen rotundum. Which nerve of this branch supplies the gingiva, posterior cheek, and nasal floor?

Posterior superior alveolar nerve

A muscle enables extension of the forearm at the elbow joint. What is the insertion site of this muscle?

Proximal radius The proximal radius is a site of insertion for the muscles of the arm that enable flexion and extension of the forearm at the elbow joint. The distal humerus is also involved in the movement of the arm and forearm. The distal radius and distal ulna are not insertion sites for muscles of the arms involved in flexion and extension of the forearm. The proximal ends are the insertion site for most muscles of the arm. The proximal humerus is involved with components of the shoulder and axilla.

A hinge joint with three separate articulations has a shared synovial cavity. One of the three articulations is involved in pronation and supination of the forearm. What structure forms an articulation with the head of the radius to enable this movement?

Radial notch of the ulna Pronation and supination of the forearm are supported by the articulation between the head of the radius and the radial notch of the ulna. The articulation of the capitulum of the humerus and the head of the radius enables flexion and extension of the forearm. Flexion and extension of the forearm are also supported by the articulation between the trochlea of the humerus and the trochlear notch of the ulna.

A ball-and-socket joint with a large round humeral head and a shallow glenoid cavity is mobile and requires stabilization. QuestionHighlights What component acts as a dynamic stabilizer?

Rotator cuff The joint is the glenohumeral joint. Dynamic stabilization of this joint is facilitated by the rotator cuff. Static stabilization is facilitated by the capsule, glenohumeral ligaments, and labrum complex.

Bones of the skull are connected by synarthrosis. Which of them runs between the parietal bones?

Sagittal

An osteofibrous passageway leads from the wrist to the hand. QuestionHighlights What lies in the proximal row of the osseous plane of this structure?

Scaphoid

A female teenager demonstrates abnormal lateral deviation of the thoracic spine. What condition is likely?

Scoliosis Scoliosis is characterized by increased lateral curvature of the spine. Scoliosis is often congenital. Lumbar hyper-lordosis (saddleback/swayback) is characterized by excessive posterior rounding of the lumbar spine. Kyphosis is characterized by increased forward rounding of the thoracic spine. Kyphoscoliosis has characteristics drawn from both kyphosis and scoliosis.

Eight bones form the cranial portion of the skull. Which of them contains lesser wings?

Sphenoid The sphenoid bone contains greater and lesser wings. The occipital bone surrounds the foramen magnum. The ethmoid bone contains the cribriform plate. The temporal bone contains a tympanic portion.

The transition of the neck and the arm is formed by the clavicle, scapula, upper thoracic wall, and humerus with related muscles. What blood vessel supplies this structure?

Subclavian artery The subclavian artery enters the axilla, becomes the axillary artery, and supplies this structure. The brachial artery supplies the shoulder. The carotid arteries supply the neck, face, and brain. The internal thoracic artery supplies the breasts and anterior wall of the chest.

A muscle innervated by the radial nerve enables extension of the forearm at the elbow joint. Where does the lateral head of this muscle originate?

Superior to the radial groove of the humerus The lateral head of the triceps brachii originates superior to the radial groove of the humerus. The long head of the triceps brachii originates from the infraglenoid tubercle of the scapula. The medial head of the triceps brachii originates on the posterior surface of the shaft of the humerus, inferior to the radial groove.

A muscle within the deep layer of the posterior forearm is wrapped around the proximal end of the radius during protonation of the hand. What is a role of this muscle?

Supinator of forearm This muscle is the supinator, which supinates the forearm and hand. The extensor carpi radialis longus, extensor carpi radialis brevis, extensor carpi ulnaris are muscles of the superficial layer of the posterior forearm that are abductors of the wrist. The brachioradialis is a flexor of the elbow located in the superficial layer of the posterior forearm. The anconeus is an extensor of the elbow located in the superficial layer of the posterior forearm. The listed muscles are muscles of the posterior forearm. Functions of muscles in the posterior forearm include extension of the wrist and supination of the hand. Muscles of the anterior forearm allow for flexion of the wrist and pronation of the hand.

The tendons of the flexor digitorum superficialis, flexor digitorum profundus, flexor pollicis longus, and the median nerve are contained by an osteofibrous passageway leading from the wrist to the hand. Which structure is deep to the tendons of the largest extrinsic flexor of the forearm?

Tendons of the flexor digitorum profundus The largest extrinsic flexor of the forearm is the flexor digitorum superficialis. The tendons of the flexor digitorum profundus muscle are deep to the tendons of the flexor digitorum superficialis muscle. The median nerve and flexor retinaculum are anterior to the tendons. The tendon of the flexor pollicis longus muscle is lateral to the tendons of the flexor digitorum superficialis muscle.

A tendon arises from a muscle that laterally rotates the humerus and inserts on the inferior facet of the greater tubercle of the humerus. Question From what muscle does this tendon arise?

Teres minor

A cranial nerve with both sensory and motor components has fibers that extend into the abdomen. What activity does this nerve modulate?

The nerve is cranial nerve X, the vagus nerve. The vagus nerve is responsible for lowering resting heart rate. Accommodation is modulated by the oculomotor nerve. Near focusing is modulated by the optic nerve. Smell is modulated by the olfactory nerve.

A muscle innervated by cranial nerve VII crosses the angle of the mouth to the upper lip and inserts into the skin near the median line. What is a function of this muscle?

This muscle is the triangularis, a facial muscle that composes a part of the orbicularis oris. One function of this muscle is to emphasize vocal communication. The masseter, a muscle of mastication, elevates the mandible. The lateral pterygoid, a muscle of mastication, operates the temporomandibular joint and facilitates lateral movement of the jaw. The epicranius is a muscle of facial expression that raises the eyebrows. The muscles of facial expression insert into the skin, and the muscles of mastication insert onto the mandible.

A structure consists of the pinna and the external acoustic meatus. What feature of this structure reflects sound from behind?

Tragus The tragus, a component of the outer ear, reflects sound coming from behind the ear canal. The auricle (including antihelix and helix) amplifies sound toward the ear canal.

A structure contains the malleus, incus, and stapes. What is the general function of this structure?

Transmit vibrations from the eardrum to the oval

An osteofibrous passageway leads from the wrist to the hand. What lies in the distal row of the osseous plane of this structure?

Trapezium The capitate, hamate, trapezium, and trapezoid are located in the distal row of the osseous plane of the carpal tunnel. The scaphoid, lunate, triquetrum, and pisiform are located in the proximal row of the osseous plane of the carpal tunnel.

The joint of the first metacarpal facilitates flexion, extension, abduction, adduction, rotation, and circumduction. What other bone makes up this joint?

Trapezium The joint of the first metacarpal and trapezium is a saddle joint, which affords a greater degree of mobility to the thumb than the other carpometacarpal joints. The capitate articulates with the third metacarpal. The hamate articulates with the fifth metacarpal. The trapezoid articulates with the second metacarpal.

A compartment of the arm is innervated by the radial nerve. What muscle is contained in this compartment?

Triceps brachii

The cord of a plexus is positioned medial to the second part of the axillary artery. What nerve originates from this cord?

Ulnar nerve The structure is the medial cord of the brachial plexus. The ulnar nerve originates from the medial cord of the brachial plexus. The axillary nerve originates from the posterior cord of the brachial plexus. The dorsal scapular nerve originates from the C5 root of the brachial plexus. The musculocutaneous nerve originates from the lateral cord of the brachial plexus.

The roots and trunks of a plexus enter the posterior triangle of the neck between the anterior scalene and middle scalene. What forms the inferior trunk of this plexus?

Union of C8 and T1 roots The structure is the brachial plexus. The inferior trunk arises from the union of the C8 and T1 roots. The brachial plexus is formed by the anterior rami of C5 to C8 and most of the anterior ramus of T1. The middle trunk of the brachial plexus is formed by the continuation of the C7 root. The superior trunk of the brachial plexus is formed by the union of C5 and C6 roots.

Structures in the vertebral column increase in size as the column descends. Which part of these structures forms the walls of the spinal canal?

Vertebral arch Vertebrae increase in size as the column descends. The vertebral arch forms the walls of the foramen (spinal canal). Pedicles connect the vertebral arch to the body. The transverse and spinous processes project laterally and inferiorly from the vertebral arch.

median nerve innervates

anterior forearm

ulnar nerve innervates

flexor carpi ulnaris and medial half of flexor digitorum profundus, most hand muscles

An artery originating from the axillary artery has branches from the inferior margin of the pectoralis major muscle that contribute to the vascular supply of the breast in women. How many branches arise from the part of the axillary artery from which this structure originates?

2 The structure is the lateral thoracic artery, which arises from the second part of the axillary artery. The second part of the axillary artery gives rise to two branches. The first part of the axillary artery gives rise to one branch. The third part of the axillary artery gives rise to three branches. In total, six branches arise from the axillary artery.

An artery originating from the axillary artery supplies the glenohumeral joint and the head of the humerus. QuestionHighlights How many branches arise from the part of the axillary artery from which this structure originates?

3

An artery originating from the axillary artery passes through the quadrangular space of the teres major, teres minor, triceps brachii, and humerus. How many branches arise from the part of the axillary artery that this structure originates from?

3 The structure is the posterior circumflex humeral artery, which arises from the third part of the axillary artery. The third part of the axillary artery gives rise to three branches. The first part of the axillary artery gives rise to one branch. The second part of the axillary artery gives rise to two branches. In total, six branches arise from the axillary artery.

Subclavian artery

Both a left and right, blood vessels that supply blood to the shoulders and upper limbs.

The cord of a plexus is positioned medial to the second part of the axillary artery. QuestionHighlights What roots are the origin of this structure?

C8 and T1

Which vertebrae contains an odontoid process that assists in rotational movement?

C2 C2 (the axis) has the odontoid process. The odontoid process is a bony projection that serves as a point of attachment for soft tissue that stabilizes the junction that enables rotational movement. C2 has this process rather than C1, C3, or C4, as it is the primary weight-bearing cervical vertebrae.

The cord of a plexus is positioned posterior to the second part of the axillary artery. What roots are the origin of this structure?

C5 to T1 The structure is the posterior cord of the brachial plexus, which originates from C5 to T1. The lateral cord of the brachial plexus originates from C5 to C7. Small segmental branches of the brachial plexus progress from C5 to C8 to the muscles of the neck. The medial cord of the brachial plexus originates from C8 and T1.

brachial plexus

C5-C8, T1

A square-shaped muscle in the deep layer of the distal forearm originates from a linear ridge on the lower ulna. Where does it insert?

Flat surface of the radius The muscle is the pronator quadratus, which inserts on the anterior flat surface of the radius. The flexor pollicis longus inserts on the palmar surface of the distal phalanx after passing through the carpal tunnel. The flexor digitorum profundus inserts on the distal phalanx of digits 2, 3, 4, and 5.

A muscle beneath the biceps brachii is innervated by the musculocutaneous nerve. QuestionHighlights What movement does this structure enable?

Flexion of the elbow The brachialis muscle enables flexion of the elbow. The triceps brachii enables extension of the elbow. The biceps brachii enables supination of the forearm when the elbow joint is flexed. The pronator teres enables pronation of the forearm.

A group of muscles is associated with flexion of the wrist joint. Which muscle of this group is also responsible for abduction of the wrist?

Flexor carpi radialis The flexor carpi radialis facilitates abduction of the wrist. The flexor carpi ulnaris, palmaris longus, flexor carpi radialis, flexor digitorum superficialis, and flexor digitorum profundus are all associated with the flexion of the wrist joint.

Emissary veins that drain the nasal cavity of blood pass through the anterior cranial fossa. What provides passage of this structure?

Foramen cecum The foramen cecum is located within the anterior cranial fossa and provides passage of the emissary veins. The cribriform plate is also located within the anterior cranial fossa but does not provide passage of the emissary veins. The foramen lacerum is located within the middle cranial fossa. The superior orbital fissure is located between the anterior and middle cranial fossa.

Structures protecting the spinal cord form foramina between discrete bodies, arches, and pedicles. Which of these structures is characterized by having a large cone-shaped transverse process?

L5 The structures are vertebrae. L5 is characterized by a large cone-shaped transverse process; L2, L3, and L4 are not characterized this way due to the sacrovertebral articulation.

The transition of the neck and the arm is formed by the clavicle, scapula, upper thoracic wall, and humerus with related muscles. Question What exits this structure directly through the pectoralis minor muscle?

Medial pectoral nerve The medial pectoral nerve exits the axilla directly through the pectoralis minor muscle. The axillary vein enters the neck and continues to become the subclavian vein. The intercostobrachial nerve passes through the axilla directly through the medial wall. The lateral thoracic artery exits the axilla through the fascia inferior to the pectoralis minor muscle.

A muscle in the anterior compartment of the arm is innervated by the musculocutaneous nerve and enables flexion of the glenohumeral joint. Where does the long head of this muscle originate?

Supraglenoid tubercle of the scapula The long head of the biceps brachii originates from the supraglenoid tubercle of the scapula. The brachialis originates from parts of the intermuscular septum on the medial side. The short head of the biceps brachii originates from the coracoid process. The long head of the triceps brachii originates from the infraglenoid tubercle of the scapula.

An osteofibrous passageway leads from the wrist to the hand. What enables free movement of tendons within this structure?

Synovial sheath Synovial sheaths surrounding the tendons in the carpal tunnel facilitate free movement. The tunnel is formed by the carpal arch, osseous plane, and flexor retinaculum.

A bone with an S-shaped contour serves as an attachment between the trunk and the upper limb. Where does this attachment articulate medially?

The bony attachment is the clavicle, which articulates medially with the manubrium of the sternum and the first costal cartilage. The clavicle articulates laterally with the acromion of the scapula. The head of the humerus articulates with the glenoid cavity of the scapula. The scapula articulates with the head of the humerus.

The superior border of a flat triangular bone contains a hook-like structure that projects anterolaterally. How is this structure positioned relative to the lateral part of the clavicle?

The coracoid process of the scapula is inferior to the lateral clavicle. The scapula has superior, lateral, and medial borders.

The largest cranial nerve contains three divisions that leave the skull through separate foramina; one travels through the foramen ovale. Which nerve of this branch supplies the skin on the side of the head?

The divisions of the trigeminal nerve are the ophthalmic branch, maxillary branch, and mandibular branch. The mandibular branch travels through the foramen ovale. The auriculotemporal nerve, buccal nerve, inferior alveolar nerve, and lingual nerve are all part of the mandibular branch. The auriculotemporal nerve supplies the skin on the side of the head. The buccal nerve carries sensory information from the skin of the cheek. The inferior alveolar nerve carries sensation from the lower teeth. The lingual nerve supplies the anterior part of the tongue.

The largest cranial nerve contains three divisions that leave the skull through separate foramina; one exits through the foramen rotundum. Which nerve of this branch supplies the lacrimal gland, forehead, and cheek?

The divisions of the trigeminal nerve are the ophthalmic branch, maxillary branch, and mandibular branch. The maxillary branch exits through the foramen rotundum. The nerves of the maxillary branch are the infraorbital nerve, zygomatic nerve, sphenopalatine nerve, and posterior superior alveolar nerve. The zygomatic nerve supplies the lacrimal gland, forehead, and cheek. The infraorbital nerve supplies the skin and mucous membranes of the middle face. The posterior superior alveolar nerve supplies the gingiva, posterior cheek, and nasal floor. The sphenopalatine nerve supplies the soft palate, hard palate, nasal cavity, and pharynx.

The largest cranial nerve contains three divisions that leave the skull through separate foramina; one exits through the superior orbital fissure. Which nerve of this branch becomes the anterior ethmoid nerve?

The divisions of the trigeminal nerve are the ophthalmic branch, maxillary branch, and mandibular branch. The ophthalmic branch exits through the superior orbital fissure. The nerves of the ophthalmic branch are the frontal, lacrimal, and nasociliary nerves. The nasociliary nerve becomes the anterior ethmoid nerve. The maxillary nerve is part of the maxillary branch.

A structure contains the malleus, incus, and stapes. What facilitates air pressure equalization for this structure?

The eustachian tube connects the tympanic cavity of the middle ear with the nasopharynx and allows air pressure to equalize. The ossicles are connected to the oval window on the cochlea and serve to transfer sound waves. The tympanic membrane separates the outer and middle ear.

What structure is supported by the lateral boundaries of the anterior cranial fossa?

The frontal lobes of the cerebrum are supported by the lateral portions of the anterior cranial fossa. The brainstem is contained by the posterior cranial fossa. The pituitary gland and temporal lobes of the brain are supported by the middle cranial fossa.

A musculotendinous collar surrounds the anterior, superior, and posterior aspects of the glenohumeral joint. Besides the tendons of the rotator cuff, what composes this structure?

The joint capsule blends with the tendons of the rotator cuff to form this musculotendinous collar. Glenohumeral ligaments are involved with other aspects of joint stability. The subscapularis and teres minor are muscles of the rotator cuff, not parts of the musculotendinous collar.

Landmarks on the proximal end of the humerus are the site of attachment for rotator cuff muscles. Relative to the greater of these landmarks, where is the lesser landmark?

The landmark is the lesser tubercle, which is positioned anteriorly with respect to the greater tubercle. The greater tubercle is positioned laterally with respect to the head of the humerus and has superior and posterior surfaces containing facets for tendon attachment.

A structure consists of the pinna and the external acoustic meatus. What does this structure direct sound toward?

The outer ear collects, amplifies, and directs sound towards the tympanic membrane. The antihelix is a prominent ridge of cartilage composing part of the auricle. The concha is a depression next to the ear canal. The posterior auricular is an extrinsic muscle associated with the outer ear.

A structure consists of the pinna and the external acoustic meatus. What vessel supplies this structure?

The posterior auricular artery, the superficial temporal artery, and the occipital artery are the branches of the external carotid artery that supply the outer ear. The anterior inferior cerebellar artery supplies the inner ear. The facial artery supplies the muscles and skin of the face. The posterior superior alveolar artery supplies the teeth.

The anterolateral projection of a bone arches over the glenohumeral joint and has a small oval facet on its distal end for articulation. What structure does this projection articulate with?

The structure is the acromion, a projection of the spine of the scapula that articulates with the clavicle. The acromion is not connected to the humerus or thorax.

A structure contains ossicles connected to the tympanic membrane. What is connected to the membrane of the oval window?

The stapes is connected to the membrane of the oval window. The malleus is directly connected to the tympanic membrane. The malleus articulates with the incus, which articulates with the stapes. The umbo is a depression of the eardrum located near the handle of the malleus.

The largest cranial nerve arises directly from the pons. What discrete aspect of this structure is an important site for reflexes?

The structure is the trigeminal nerve. The spinal trigeminal nucleus is an important site for the reflexes of coughing, sneezing, and gagging. Fibers from three discrete units (mesencephalic nuclei, principal nuclei, and spinal trigeminal nuclei) merge to form a sensory root. The trigeminal ganglion is formed by the trigeminal sensory root, motor root, and mandibular nerve. The frontal nerve is a branch of the ophthalmic nerve, a trigeminal division. The principal nucleus of the trigeminal nerve receives sensory information about touch and pressure.

A structure separates the external ear from the middle ear. What is the general function of this structure?

The structure is the tympanic membrane (eardrum), which translates soundwaves into mechanical vibrations. The outer ear reflects incoming sound towards the eardrum. Transmission of neuroelectrical signals to the brain occurs in the inner ear. The middle ear transmits vibrations from the eardrum to the oval.

A portion of bone oriented horizontally between the proximal humerus and the shaft is weaker than other areas. What is the name of this portion, which is a common fracture site?

The surgical neck is weaker than other areas of the proximal humerus (anatomical neck, head, and tubercles) and is a common site of fracture.

A tendon arises from a muscle that medially rotates the arm at the glenohumeral joint and inserts onto the lesser tubercle of the humerus. From what muscle does this tendon arise?

The tendon described arises from the subscapularis. The tendon of the infraspinatus inserts on the middle facet of the greater tubercle. The tendon of the supraspinatus inserts onto the superior facet of the greater tubercle. The tendon of the teres minor inserts on the inferior facet of the greater tubercle of the humerus.

A group of muscles arises from various locations on the scapula and inserts in the proximal humerus. Which muscle of this group inserts most posteriorly?

This group of muscles is the rotator cuff. The rotator cuff is composed of the infraspinatus, subscapularis, supraspinatus, and teres minor. The most posterior insertion of the group is by the teres minor, upon the greater tuberosity.

musculocutaneous nerve innervates

biceps brachii, brachialis, coracobrachialis (anterior muscles of arm)

axillary nerve innervates

deltoid and teres minor

A structure communicates superiorly with the lateral wall of the axilla. Question What does this structure communicate through inferiorly?

Cubital fossa The structure is the arm. Inferiorly, it communicates with the forearm through the cubital fossa, a triangular depression formed by the brachioradialis and pronator teres. The brachial artery passes through the anterior compartment. The capitulum of the humerus and the trochlear notch of the ulna are components of the elbow joint.

The transition of the neck and the arm is formed by the clavicle, scapula, upper thoracic wall, and humerus with related muscles. What directly enters through the medial wall of this structure?

Intercostobrachial nerve The intercostobrachial nerve passes through the axilla directly through the medial wall. The axillary vein enters the neck and continues to become the subclavian vein. The lateral thoracic artery exits the axilla through the fascia inferior to the pectoralis minor muscle. The medial pectoral nerve exits the axilla directly through the pectoralis minor muscle.

A flexor of the forearm at the elbow joint is innervated by the radial nerve on a lateral component and the musculocutaneous nerve. QuestionHighlights Where does this muscle originate on the medial side?

Intermuscular septum The brachialis originates from parts of the intermuscular septum on the medial side. The short head of the biceps brachii originates from the coracoid process. The long head of the triceps brachii originates from the infraglenoid tubercle of the scapula. The long head of the biceps brachii originates from the supraglenoid tubercle of the scapula.

A purely efferent cranial nerve is involved in deliberate and involuntary movements. What is a general function of this nerve?

The nerve is cranial nerve XII, the hypoglossal nerve. The hypoglossal nerve modulates voluntary movements of the tongue such as moving food. It also modulates involuntary movements like the clearing of saliva from the mouth. Detection of odiferous molecules is modulated by the olfactory nerve, a purely afferent nerve. The light reflex is modulated by the optic nerve, a purely afferent nerve. Facilitation of balance is modulated by the vestibulocochlear nerve, a purely afferent nerve.

A fossa is composed of the frontal bone, ethmoid bone, and lesser wings of the sphenoid bone. What does this structure contain?

The olfactory bulb is contained within the anterior cranial fossa. The brainstem and cerebellum are contained within the posterior cranial fossa. The pituitary gland is contained within the middle cranial fossa.

The largest cranial nerve arises directly from the pons. What discrete aspect of this structure regulates biting force?

The mesencephalic nucleus of the trigeminal nerve (the indicated structure) contains primary afferent proprioceptors and senses movement of the teeth, which regulates biting force. Fibers from three discrete units (mesencephalic nuclei, principal nuclei, and spinal trigeminal nuclei) merge to form a sensory root. The trigeminal ganglion is formed by the trigeminal sensory root, motor root, and mandibular nerve. The principal nucleus of the trigeminal nerve receives sensory information about touch and pressure.

A fossa is composed of the sphenoid bone and the temporal bones. What is this structure bound to on its front surface?

The middle cranial fossa is bound in front by the anterior margin of the chiasmatic groove. The middle cranial fossa is limited behind by the dorsum sellae. The middle cranial fossa is limited laterally by the parietals and temporals.

A purely afferent cranial nerve is responsible for detection of odiferous molecules. What can result from damage to this nerve?

The nerve is cranial nerve I, the olfactory nerve. Damage to the olfactory nerve can cause parosmia (distorted sense of smell), anosmia (inability to smell), or distorted sense of taste. Damage to the glossopharyngeal nerve can lead to an absence of the gag reflex. Damage to the vestibulocochlear nerve can cause nystagmus. Damage to the facial nerve can lead to Bell's palsy, a condition of temporary facial paralysis.

A purely efferent cranial nerve affects accommodation. What can result from damage to this nerve?

The nerve is cranial nerve III, the oculomotor nerve. Fibers of the oculomotor nerve control pupil restriction, pupil dilation, and accommodation. Damage to this nerve can cause double vision and inability to coordinate movement of both eyes. Damage to the facial nerve can lead to Bell's palsy. Damage to the olfactory nerve can cause lack of taste. Damage to the vestibulocochlear nerve can cause vertigo.

A cranial nerve with both sensory and motor components sends the sensation of taste from the posterior portion of the tongue. What type of muscle does this nerve innervate?

The nerve is cranial nerve IX, the glossopharyngeal nerve. The glossopharyngeal nerve innervates the stylopharyngeus muscle of the pharynx. The facial nerve innervates the muscles of facial expression. The trigeminal nerve innervates the muscles of mastication. The muscles of phonation are innervated by the vagus nerve.

The vertebral canal is smallest in which region of the vertebral column?

Thoracic The vertebral canal is smallest in the thoracic region as it changes shape with the vertebral column. It is larger in the cervical and lumbar regions. The canal ends before reaching the pelvic region.

What grouping of vertebrae displays a heart-shaped body?

Thoracic Thoracic vertebrae are characterized by a heart-shaped body. Cervical vertebrae are characterized by a square-shaped body. Lumbar vertebrae are characterized by a kidney-shaped body. Sacral vertebrae are characterized by being fused.

phrenic nerve innervates

diaphragm