MSK TEST 2

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Questions and Answers

Which nerve innervates the posterior or extensor compartment of the arm?

Ulnar nerve

Radial nerve (correct)

Musculocutaneous nerve

Median nerve

Which of the following muscles is NOT located in the anterior or flexor compartment of the arm?

Biceps brachii

Triceps brachii (correct)

Brachialis

Coracobrachialis

What is the function of the medial and lateral intermuscular septae in the arm?

They divide the arm into anterior and posterior compartments. (correct)

They protect the neurovascular structures of the arm.

They facilitate the movement of the arm.

They provide attachment points for the muscles of the arm.

Which of the following muscles is not innervated by the musculocutaneous nerve in the anterior compartment of the arm?

Triceps brachii Signup and view all the answers

Which of the following statements about the arm compartments is NOT correct?

The anterior compartment is innervated by the radial nerve. Signup and view all the answers

What is the origin of the short head of the biceps brachii muscle?

Coracoid process of the scapula Signup and view all the answers

Which nerve innervates the majority of the muscles in the posterior compartment of the forearm?

Radial nerve Signup and view all the answers

Which muscle does NOT originate from the medial epicondyle of the humerus via the common flexor tendon?

Flexor carpi ulnaris (FCU) Signup and view all the answers

What is the insertion of the triceps brachii muscle?

Olecranon process of the ulna Signup and view all the answers

What is the function of the coracobrachialis muscle?

Adduction of the arm Signup and view all the answers

Which layer of the anterior forearm muscles includes the Flexor Digitorum Superficialis?

Intermediate layer Signup and view all the answers

Which nerve innervates the Flexor Carpi Ulnaris and the medial half of the Flexor Digitorum Profundus?

Ulnar nerve Signup and view all the answers

What is the primary action of the muscles in the Superficial layer of the anterior forearm?

All of the above Signup and view all the answers

How many layers are the muscles of the anterior forearm compartment divided into?

3 Signup and view all the answers

Which of the following muscles is NOT part of the Deep layer of the anterior forearm muscles?

Flexor Carpi Radialis Signup and view all the answers

Which nerve is responsible for innervating the radial muscles of the upper limb?

Radial nerve Signup and view all the answers

Which of the following muscles performs elbow flexion with supination?

Biceps Signup and view all the answers

What is the primary function of the extensor retinaculum in the forearm?

To retain the extensor tendons in position Signup and view all the answers

What is the primary function of the flexor retinaculum in the wrist?

To convert the anterior concavity of the carpus into a carpal tunnel Signup and view all the answers

What is the primary purpose of the synovial sheaths that invest the extensor tendons as they pass over the dorsum of the wrist?

To reduce friction between the extensor tendons and the bones Signup and view all the answers

Which muscle is NOT part of the superficial layer of the posterior forearm?

Abductor pollicis longus (APL) Signup and view all the answers

What is the primary action of the brachioradialis muscle?

Flexion of the elbow in mid-pronation Signup and view all the answers

Which nerve innervates ALL the extensor muscles of the posterior forearm?

Radial nerve Signup and view all the answers

Which statement about the origins of the posterior forearm muscles is TRUE?

The superficial muscles originate from the lateral epicondyle via a common extensor tendon Signup and view all the answers

If a muscle in the posterior forearm crosses the wrist, what primary action does it perform?

Extension of the wrist Signup and view all the answers

Which muscle in the anterior forearm is responsible for pronation of the forearm?

Pronator Teres Signup and view all the answers

Which muscle in the anterior forearm is known to be absent in around 12-20% of the population?

Palmaris Longus Signup and view all the answers

Which muscle is the only one in the anterior forearm compartment innervated by the ulnar nerve?

Flexor Carpi Ulnaris Signup and view all the answers

Where does the Flexor Carpi Ulnaris muscle insert?

Base of the 5th metacarpal Signup and view all the answers

Which muscle in the anterior forearm serves as the site for potential median nerve entrapment, leading to pronator syndrome?

Pronator Teres Signup and view all the answers

What is the nerve supply to the Flexor Carpi Radialis muscle?

Median Nerve Signup and view all the answers

Which muscle is the only muscle in the intermediate layer of the anterior forearm?

Flexor Pollicis Longus Signup and view all the answers

What is the origin of the Flexor Digitorum Profundus muscle?

Anterior & medial surface of ulna Signup and view all the answers

Where does the Flexor Pollicis Longus muscle insert?

Base of distal phalanx of thumb Signup and view all the answers

Which muscle is described as 'One of the Carpal Tunnel muscles'?

Flexor Pollicis Longus Signup and view all the answers

What does the Pronator Quadratus muscle originate from?

Anterior surface of distal ¼ of ulna Signup and view all the answers

What is the primary function of the Flexor Digitorum Superficialis muscle?

Flexion of fingers # 2-5 at the PIP joint Signup and view all the answers

Which muscle in the anterior forearm has dual innervation?

Flexor Digitorum Profundus Signup and view all the answers

Which nerve innervates the brachioradialis muscle?

Radial nerve Signup and view all the answers

What is the primary function of the brachioradialis muscle?

Elbow flexion in mid-pronation Signup and view all the answers

Which of the following is NOT a function of the extensor digitorum muscle?

Abduction of the fingers Signup and view all the answers

What is the purpose of the dorsal digital expansions (extensor hoods) on the fingers?

To provide stability to the extensor tendons Signup and view all the answers

Which muscle is considered part of the 'mobile wad of three' in the forearm?

Brachioradialis Signup and view all the answers

Which layer of the posterior forearm compartment contains the Extensor Digitorum muscle?

Superficial layer Signup and view all the answers

What is the primary action of the Supinator muscle?

Supination of the forearm Signup and view all the answers

Which of the following muscles is part of the deep layer of the posterior forearm compartment?

Supinator Signup and view all the answers

If a muscle in the posterior forearm compartment crosses the digits, what primary action does it perform?

Extension of the digits Signup and view all the answers

Which of the following statements about the innervation of the posterior forearm compartment is correct?

The muscles are innervated by the radial nerve Signup and view all the answers

What is the primary cause of Medial Epicondylitis (Golf Elbow)?

Forceful and repeated bending of the wrist and fingers Signup and view all the answers

What is the primary symptom of Lateral Epicondylitis (Tennis Elbow)?

Tenderness and pain at the lateral epicondyle Signup and view all the answers

If the radial nerve is injured, which terminal branch would be affected?

Posterior interosseous nerve Signup and view all the answers

Which muscle(s) would be affected by a radial nerve injury?

Extensor Carpi Radialis Longus and Brevis Signup and view all the answers

What is the primary function of the flexor retinaculum in the wrist?

To provide a pulley system for the flexor tendons Signup and view all the answers

Which muscle's tendon bounds the anatomical snuff box medially?

Extensor Pollicis Longus (EPL) Signup and view all the answers

Where is the anatomical snuff box located?

Posterolateral aspect of the wrist Signup and view all the answers

Which muscle has its origin at the middle 1/3 of the posterior surface of ulna?

Extensor Pollicis Longus (EPL) Signup and view all the answers

Where does the Extensor Indicis muscle insert?

Dorsal digital expansion of the 2nd finger Signup and view all the answers

What structures form the floor of the anatomical snuff box?

Scaphoid and Trapezium bones Signup and view all the answers

What is the primary function of the triangular tendinous aponeurosis described in the text?

Extension of the interphalangeal joints Signup and view all the answers

Which muscles attach to the sides of the triangular tendinous aponeurosis mentioned in the text?

Interossei and Lumbrical Signup and view all the answers

Where does the Extensor Carpi Ulnaris muscle originate from?

Lateral epicondyle of humerus Signup and view all the answers

What is the insertion point of the Anconeus muscle?

Proximal of posterior surface of ulna Signup and view all the answers

Which nerve is associated with the Supinator muscle?

Radial nerve Signup and view all the answers

Which of the following muscles is responsible for abducting the thumb?

Abductor Pollicis Brevis Signup and view all the answers

Which muscle is responsible for opposing the little finger?

Opponens Digiti Minimi Signup and view all the answers

Which of the following muscles is part of the central group of intrinsic hand muscles?

Adductor Pollicis Signup and view all the answers

Which nerve innervates the Thenar group of muscles?

Median nerve Signup and view all the answers

What is the primary function of the Palmaris Brevis muscle?

To wrinkle the skin of the medial hand Signup and view all the answers

Which muscle is responsible for adducting the thumb?

Adductor Pollicis Signup and view all the answers

Which nerve innervates the Hypothenar group of muscles?

Ulnar nerve Signup and view all the answers

What is the primary function of the Lumbrical muscles?

To flex the metacarpophalangeal joints Signup and view all the answers

What is the primary function of the Carpal Tunnel?

To provide a passageway for the median nerve and flexor tendons Signup and view all the answers

Which of the following statements about the intrinsic muscles of the hand is CORRECT?

They are divided into Thenar, Hypothenar, and Interossei muscle groups Signup and view all the answers

What is the significance of the 90-degree medial rotation of the thumb's long axis relative to the other fingers?

It causes the thumb to move at right angles to the other fingers Signup and view all the answers

Which of the following statements about the palm and dorsum of the hand is CORRECT?

The palm and dorsum are defined relative to the axis of the middle finger Signup and view all the answers

What is the primary function of the Flexor Digitorum Superficialis (FDS) muscle?

To flex the proximal interphalangeal joints of the fingers Signup and view all the answers

Which of the following statements about the innervation of the intrinsic hand muscles is CORRECT?

The interossei muscles are innervated by both the median and ulnar nerves Signup and view all the answers

What is the primary function of the Flexor Pollicis Longus (FPL) muscle?

To flex the interphalangeal joint of the thumb Signup and view all the answers

Which of the following muscles is NOT considered part of the intrinsic hand muscles?

Flexor Digitorum Profundus Signup and view all the answers

What is the primary function of the lumbrical muscles?

Extension of the fingers at the interphalangeal joints Signup and view all the answers

Which of the following muscles is NOT part of the central group of intrinsic hand muscles?

Abductor pollicis brevis Signup and view all the answers

Which muscle in the central group of intrinsic hand muscles inserts into the lateral side of the index finger?

Dorsal interosseous #1 Signup and view all the answers

What is the action of the palmar interosseous muscles?

Adduction of the fingers Signup and view all the answers

Which of the following muscles is NOT part of the dorsal interosseous group?

Palmar interosseous #3 Signup and view all the answers

Which muscle in the central group of intrinsic hand muscles inserts into the medial side of the ring finger?

Dorsal interosseous #4 Signup and view all the answers

What is the action of the dorsal interosseous muscles?

Abduction of the fingers Signup and view all the answers

Which muscle in the central group of intrinsic hand muscles inserts into the little finger?

Palmar interosseous #3 Signup and view all the answers

How many lumbrical muscles are there in the hand?

4 Signup and view all the answers

What is the most likely site of injury to the axillary nerve?

As it wraps around the posterior aspect of the humeral neck Signup and view all the answers

Which of the following is NOT a function of the radial nerve?

Motor to the flexor muscles of the anterior forearm Signup and view all the answers

What is the relationship between the radial nerve and the radial groove of the humerus?

The radial nerve wraps around the radial groove Signup and view all the answers

Which of the following sensory branches arises from the radial nerve in the posterior arm?

Posterior cutaneous nerve of the forearm and lower lateral cutaneous nerve of the arm Signup and view all the answers

Which of the following terminal branches of the radial nerve would be affected by an injury to the radial nerve?

All of the above Signup and view all the answers

What is the primary function of the median nerve?

Motor innervation of the flexor muscles of the forearm and hand Signup and view all the answers

Which of the following is a common cause of median nerve compression?

Carpal tunnel syndrome Signup and view all the answers

What is the primary symptom of carpal tunnel syndrome as it progresses?

All of the above Signup and view all the answers

Which of the following is NOT a risk factor for carpal tunnel syndrome?

Radial nerve injury Signup and view all the answers

Which nerve innervates the flexor muscles in the posterior compartment of the forearm?

None of the above Signup and view all the answers

Which nerve innervates muscles of the anterior compartment of the arm and provides sensory supply to the skin of the anterolateral forearm?

Median nerve Signup and view all the answers

Injury to the Musculocutaneous nerve is most likely to occur at which site?

Coracobrachialis muscle belly Signup and view all the answers

Which spinal nerve root is responsible for the extension of the arm at the elbow in the upper limb?

C7 Signup and view all the answers

Which nerve primarily provides motor innervation to the Coracobrachialis muscle in the anterior arm?

Musculocutaneous nerve Signup and view all the answers

In the clinical test for the C8 dermatome, what sensation is expected on the skin?

Skin of digits 4 and 5 Signup and view all the answers

Which branch of the brachial plexus exits 'inferior' to the clavicle and is primarily located in the axilla?

Axillary nerve Signup and view all the answers

Which muscle in the upper limb is responsible for finger abduction according to the myotome information provided?

Finger abductors Signup and view all the answers

Which is a terminal branch of the brachial plexus located 'superior' to the clavicle?

Long Thoracic nerve Signup and view all the answers

What is the primary muscle strength tested in the clinical evaluation of the C6 myotome in the upper limb?

Biceps Signup and view all the answers

Which nerve root is associated with muscle strength testing of finger flexors in the upper limb?

C8 Signup and view all the answers

Which of the following nerve injuries would result in an 'ulnar claw hand' deformity?

Ulnar nerve injury Signup and view all the answers

Which spinal nerve roots contribute to the formation of the ulnar nerve?

C8, T1 Signup and view all the answers

Which of the following statements about dermatomes and myotomes is correct?

Both a and b Signup and view all the answers

What is the most likely site of ulnar nerve injury?

As it passes posterior to the medial epicondyle of the humerus Signup and view all the answers

Which of the following structures does the ulnar nerve NOT innervate?

Thenar eminence muscles Signup and view all the answers

Which arteries turn around the surgical neck of the humerus to supply the muscles attached to the proximal end of the humerus?

Anterior and posterior circumflex humeral arteries Signup and view all the answers

What is the name of the artery after it passes the inferior border of teres major or pectoralis major?

Brachial artery Signup and view all the answers

Which of the following is NOT a main branch of the brachial artery?

Radial artery Signup and view all the answers

Where does the brachial artery end?

In the distal part of the cubital fossa Signup and view all the answers

Which of the following is NOT a branch of the ulnar artery in the forearm?

Supplies the muscles of the lateral compartment Signup and view all the answers

Which of the following statements about the ulnar artery is CORRECT?

It is the larger of the two terminal branches of the brachial artery Signup and view all the answers

What is the second branch given off from the second part of the axillary artery?

Lateral thoracic artery Signup and view all the answers

Which of the following is NOT a branch of the third part of the axillary artery?

Lateral thoracic artery Signup and view all the answers

Which muscle does the axillary artery pass between at the start of its course?

Pectoralis major and teres major Signup and view all the answers

What is the primary function of the subscapular artery?

Supplying the muscles of the scapular region Signup and view all the answers

Which part of the axillary artery gives off the superior thoracic artery?

First part Signup and view all the answers

Which artery supplies the pectoral and deltoid regions?

Thoracoacromial artery Signup and view all the answers

Which artery is the major source of blood supply for the dorsal surface of the hand?

Radial artery Signup and view all the answers

Which arterial arch is formed by the branches of the radial artery at the level of the carpal bones?

Dorsal arterial arch Signup and view all the answers

Which anatomical structure does the radial artery pass through in the distal part of the forearm?

Anatomical snuff box Signup and view all the answers

Which arterial arch is formed by the terminal branches of the radial and ulnar arteries?

Both deep and superficial palmar arches Signup and view all the answers

Which interosseous space does the radial artery pass through to enter the palm of the hand?

First interosseous space Signup and view all the answers

Which muscle covers the radial artery as it descends on the lateral side of the forearm?

Brachioradialis Signup and view all the answers

What structures form the walls of the axilla?

Pectoral region and scapular region Signup and view all the answers

Which region is considered a transition area between the neck and the upper limb?

Axilla Signup and view all the answers

Which artery supplies the structures passing through the axilla?

Subclavian artery Signup and view all the answers

What structures pass through the axilla space?

Axillary artery and its branches Signup and view all the answers

Which vein drains deoxygenated blood from the upper limb?

Both superficial veins and deep veins Signup and view all the answers

What structure does NOT form a wall of the axilla?

Humerus Signup and view all the answers

What is the primary function of the glenohumeral (shoulder) joint?

To allow for a wide range of motion in the upper limb Signup and view all the answers

Which axis of the glenohumeral joint controls the movements of abduction and adduction?

Antero-posterior axis Signup and view all the answers

What is the purpose of the glenoid labrum in the glenohumeral joint?

To deepen the glenoid cavity and improve the congruency of the articular surfaces Signup and view all the answers

What is the primary function of the capsular ligaments of the glenohumeral joint?

To allow for a wide range of motion while maintaining joint stability Signup and view all the answers

Where is the shoulder joint most vulnerable to dislocation?

Inferiorly Signup and view all the answers

What is the primary function of the scapulothoracic joint?

Provides a movable base for the humerus, increasing arm range of motion at the shoulder joint Signup and view all the answers

Which of the following is NOT a movement associated with the scapulothoracic joint?

Circumduction Signup and view all the answers

What is the approximate displacement of the inferior angle of the scapula during scapular rotation?

10 - 12 cm Signup and view all the answers

Which of the following statements about the scapulothoracic joint is CORRECT?

It provides stability for overhead work and absorbs shocks to outstretched arms Signup and view all the answers

Which of the following muscles is primarily responsible for upward rotation of the scapula?

Serratus anterior Signup and view all the answers

What is the function of the Transverse Humeral Ligament?

Acts as a 'retinaculum' for the long head of the biceps brachii tendon Signup and view all the answers

Where does the Coracohumeral Ligament extend from and to?

From the coracoid process to the greater tubercle of the humerus Signup and view all the answers

Which structure forms an arch that prevents superior displacement of the humerus?

Coracoacromial Arch Signup and view all the answers

What purpose do bursae around the shoulder joint serve?

To reduce friction between muscles and tendons Signup and view all the answers

Where is the Subacromial bursa located?

Between the acromion and supraspinatus muscle Signup and view all the answers

In the context of shoulder joint movements, why is adduction in the frontal plane starting from the position of reference considered mechanically impossible?

The trunk blocks adduction. Signup and view all the answers

Why does impingement of the supraspinatus tendon occur beneath the acromial arch?

A result of inflammation and swelling of the supraspinatus tendon. Signup and view all the answers

What is the significance of extension in relation to adduction in shoulder joint movements?

Extension facilitates adduction. Signup and view all the answers

Why is abduction of the shoulder joint limited to reaching 180°?

Due to the presence of the acromial arch. Signup and view all the answers

What role does the subdeltoid bursa play between the deltoid and the fibrous capsule?

Allows for smooth movement between deltoid and fibrous capsule. Signup and view all the answers

What is the range of motion for elevation of the clavicle at the sternoclavicular joint?

$60^\circ$ Signup and view all the answers

Which ligament anchors the lateral end of the clavicle and prevents superior dislocation of the acromioclavicular joint?

Coracoclavicular Ligament Signup and view all the answers

What type of joint is the sternoclavicular joint?

Plane synovial joint Signup and view all the answers

What is the range of motion for protraction and retraction of the clavicle at the sternoclavicular joint?

$25-30^\circ$ Signup and view all the answers

What type of joint is the glenohumeral (shoulder) joint?

Ball and socket synovial joint Signup and view all the answers

What is the normal range of active flexion at the elbow joint?

145° Signup and view all the answers

Which of the following structures forms part of the proximal radio-ulnar joint?

Annular ligament Signup and view all the answers

What is the primary function of the proximal radio-ulnar joint?

Rotation of the forearm Signup and view all the answers

Which of the following structures is NOT part of the proximal radio-ulnar joint?

Capitellum of the humerus Signup and view all the answers

What is the range of passive flexion at the elbow joint?

160° Signup and view all the answers

What type of joint is the elbow joint?

Synovial pivot joint Signup and view all the answers

Which ligaments contribute to the structural strength of the elbow joint?

Radial collateral and ulnar collateral ligaments Signup and view all the answers

Which articulation in the elbow complex involves the capitulum of the humerus?

Humero-radial joint Signup and view all the answers

Which term describes the type of movement permitted by the elbow joint?

Flexion and extension Signup and view all the answers

What makes the elbow joint structurally strong?

Bony configuration and collateral ligaments Signup and view all the answers

What is the primary function of the collateral ligaments of the radioulnar joint?

To stabilize the distal radioulnar joint during rotation of the forearm Signup and view all the answers

What is the purpose of the midcarpal joint in the wrist articular complex?

To provide a synovial planar joint between the proximal and distal rows of carpal bones Signup and view all the answers

What is the primary function of the intercarpal joints in the wrist articular complex?

To constitute a group of small synovial planar joints between the proximal or distal carpal bones Signup and view all the answers

What is the primary axis of movement associated with the radioulnar joint?

Rotation around the longitudinal axis of the forearm Signup and view all the answers

What is the primary function of the stabilization of the elbow joint during a gripping task?

To allow for maximum force production at the fist Signup and view all the answers

Which ligaments become taut during wrist flexion?

Posterior ligaments Signup and view all the answers

What is the primary axis for abduction and adduction movements of the wrist?

Through the head of the capitate Signup and view all the answers

Which of the following statements about the range of motion of the wrist is correct?

Abduction and adduction are maximal when the hand is in the plane of reference or slightly flexed. Signup and view all the answers

Which ligament connects the radius to the pisiform bone?

Radiocarpal ligament Signup and view all the answers

What is the maximum range of wrist extension according to the text?

85 degrees Signup and view all the answers

What is the defining characteristic of cubitus varus deformity?

The forearm is deviated towards the midline of the body Signup and view all the answers

What is the primary function of the medial and lateral collateral ligaments of the elbow joint?

To keep the articular surfaces in apposition and prevent sideways movements Signup and view all the answers

Which muscle is the primary extensor of the elbow joint?

Triceps brachii Signup and view all the answers

Which of the following muscles acts exclusively as a flexor of the elbow joint?

Brachialis Signup and view all the answers

What is the primary action of the biceps brachii muscle at the elbow joint?

Flexion of the elbow Signup and view all the answers

What is the primary function of the corpus callosum?

To connect the different gyri of one cerebral hemisphere to the corresponding gyri of the other hemisphere Signup and view all the answers

Which of the following groups of fibres connect the cerebral cortex to the lower centers of the CNS?

Projectional fibres Signup and view all the answers

What is the role of the thalamus in sensory signal processing?

Passing incoming signals to the appropriate cortical area Signup and view all the answers

What is the primary function of the basal ganglia?

To coordinate motor function Signup and view all the answers

Which of the following structures is an example of the projectional fibres connecting the cerebral cortex to lower CNS centers?

Internal capsule Signup and view all the answers

Where does the final analysis and interpretation of sensory signals occur?

Cerebral cortex Signup and view all the answers

What is the function of the primary sensory areas in the cerebral cortex?

Determining exact location and shape of stimuli Signup and view all the answers

What is the primary function of the association fibres in the cerebral white matter?

To join different parts of the same cerebral hemisphere Signup and view all the answers

Which part of the cerebral cortex is responsible for fully interpreting tactile sensations?

Primary sensory areas Signup and view all the answers

What is the main function of the association areas in the cerebral cortex?

Coordinating between sensory and motor areas Signup and view all the answers

Where is the primary motor area located in the brain?

Frontal lobe Signup and view all the answers

Which area of the brain is responsible for the perception of taste?

Insular lobe Signup and view all the answers

What is the function of the corticospinal tract?

Feeds spinal nerves with stimuli Signup and view all the answers

In which cortical area is the primary visual processing done?

Occipital lobe Signup and view all the answers

Where is the primary auditory area situated within the brain?

Temporal lobe Signup and view all the answers

What is the primary function of the precentral gyrus?

Producing motor signals for muscles of the hands, facial expression, and vocal apparatus Signup and view all the answers

What is the consequence of an injury to the precentral gyrus?

Motor paralysis of the contralateral side of the body Signup and view all the answers

Which part of the precentral gyrus controls the motor signals for the leg and foot muscles?

The portion extending to the medial surface Signup and view all the answers

Which artery supplies the part of the precentral gyrus responsible for leg and foot motor control?

Anterior cerebral artery Signup and view all the answers

What is the consequence of an isolated cerebrovascular accident in the part of the precentral gyrus controlling leg and foot movements?

Motor weakness of only the leg and foot muscles on the contralateral side Signup and view all the answers

Where is the Premotor area located in the brain?

Frontal lobe behind the primary motor area Signup and view all the answers

What part of the brain controls the voluntary movement of eyeballs?

Frontal Eye Field (FEF) Signup and view all the answers

What does the size of body parts on the motor homunculus represent?

Motor control allotted to those parts Signup and view all the answers

What is the function of the Frontal Eye Field (FEF) in the brain?

Coordinate movement of eyeballs Signup and view all the answers

Which part of the brain serves as a storage space for learned movement patterns?

Premotor area Signup and view all the answers

What is the role of the dura mater?

Separate the cerebral hemispheres Signup and view all the answers

Which structure of the dura mater intervenes between the cerebellum and occipital lobe of the cerebral hemispheres?

Tentorium cerebelli Signup and view all the answers

At what level does the dura mater surrounding the spinal cord end?

Vertebra S2 Signup and view all the answers

Which layer of the dura mater attaches to the inner surface of cranial cavities within the skull?

Periosteal layer Signup and view all the answers

What is the function of dural reflections within the cranial cavity?

Form incomplete partitions dividing the cranial cavity into compartments Signup and view all the answers

Which of the following is NOT a main dural sinus listed in the passage?

The petrosal sinus Signup and view all the answers

What is the primary function of the dural sinuses described in the passage?

To collect the venous blood of the brain and drain it to the circulatory system Signup and view all the answers

Which of the following statements about the transverse sinuses is INCORRECT?

They are located in the middle cranial fossa on either side of the hypophyseal fossa Signup and view all the answers

What is the purpose of the falx cerebelli described in the passage?

To separate the cerebellar hemispheres Signup and view all the answers

According to the passage, which of the following statements about the sigmoid sinuses is correct?

They are located in a groove on the interior surface of the mastoid process of the temporal bones Signup and view all the answers

What is the name of the space between the endpoint of the spinal cord and vertebra S2 that contains the roots of the spinal nerves and CSF?

Lumbar cistern Signup and view all the answers

What are the arachnoid granulations (villi) that drain the CSF into the dural sinuses?

Small finger-like projections of the arachnoid mater Signup and view all the answers

What is the primary function of the pia mater, the delicate, thin layer of connective tissue that is intimately in touch with the surface of the brain and spinal cord?

To carry the blood vessels to the depth of the nervous tissue of the CNS Signup and view all the answers

What are the denticulate ligaments that anchor the spinal cord to the deep surface of the arachnoid and dura mater?

Lateral triangular extensions of the pia mater Signup and view all the answers

What is the function of the filum terminale, an extension of the pia mater arising from the conus medullaris that extends inferiorly and fuses with the arachnoid and dura mater?

To anchor the spinal cord to the coccyx Signup and view all the answers

Which layer of the meninges is named for its 'web-like' appearance?

Arachnoid mater Signup and view all the answers

Where is the subdural space typically found?

Between the dura mater and arachnoid mater Signup and view all the answers

What structures suspend the spinal cord in the middle of its dural sheath?

Denticulate ligaments Signup and view all the answers

In the spinal cord axial view, what surrounds the dura mater?

Epidural space containing fat and blood vessels Signup and view all the answers

Which part of the neural tube develops into the cerebral ventricles?

Caudal part Signup and view all the answers

Which ventricle is connected to the central canal of the spinal cord?

Fourth ventricle Signup and view all the answers

What is the role of the choroid plexus in the cerebral ventricles?

It secretes the cerebrospinal fluid that circulates in the ventricles and other spaces Signup and view all the answers

How are the lateral ventricles connected to the third ventricle?

Through the interventricular foramen (of Monro) Signup and view all the answers

Which of the following statements about the fourth ventricle is correct?

It is bounded by the pons and upper part of the medulla anteriorly and the cerebellum posteriorly Signup and view all the answers

Which of the following is part of the vertebro-basilar system that supplies blood to the brain?

Vertebral arteries Signup and view all the answers

Study Notes

Arm Compartments

• The arm is divided into anterior and posterior compartments by the medial and lateral intermuscular septae, which are extensions of deep fascia. • The anterior compartment, also known as the flexor compartment, contains three muscles (biceps brachii, coracobrachialis, and brachialis) and is innervated by the musculocutaneous nerve. • The posterior compartment, also known as the extensor compartment, contains one muscle (triceps brachii) and is innervated by the radial nerve.

Retinacula

• The forearm (antebrachial) fascia invests the forearm muscles and thickens posteriorly to form the extensor retinaculum, which retains the extensor tendons in position. • The fascia also forms an anterior thickening, the flexor retinaculum, which converts the anterior concavity of the carpus (wrist bones) into a carpal tunnel through which the flexor tendons and median nerve pass. • The retinacula prevent bowstringing of the tendons when the hand is flexed or hyperextended at the wrist joint.

Forearm Muscles

• The forearm muscles are divided into anterior (flexor-pronator) and posterior (extensor-supinator) compartments. • All muscles of the anterior compartment are innervated by the median nerve, except for the flexor carpi ulnaris and the medial half of the flexor digitorum profundus, which are innervated by the ulnar nerve. • All muscles of the posterior compartment are innervated by the radial nerve.

Anterior Forearm Muscles

• The muscles of the anterior forearm are organized into three layers: superficial, intermediate, and deep. • The superficial layer contains the pronator teres, flexor carpi radialis, palmaris longus, and flexor carpi ulnaris muscles. • The intermediate layer contains the flexor digitorum superficialis muscle. • The deep layer contains the flexor digitorum profundus, flexor pollicis longus, and pronator quadratus muscles.

Posterior Forearm Muscles

• The muscles of the posterior forearm are organized into superficial and deep layers. • The superficial layer contains the brachioradialis, extensor carpi radialis longus, extensor carpi radialis brevis, extensor digitorum, and extensor digiti minimi muscles. • The deep layer contains the abductor pollicis longus, extensor pollicis brevis, extensor pollicis longus, and extensor indicis muscles.

Clinical Correlations

• Medial epicondylitis, also known as golfer's elbow, is a condition in which the common flexor tendon becomes painful and tender, usually as a result of a specific strain, overuse, or a direct blow. • Lateral epicondylitis, also known as tennis elbow, is a condition in which the common extensor tendon becomes painful and tender, usually as a result of a specific strain, overuse, or a direct blow. • Radial nerve injury can cause damage to the posterior cord of the brachial plexus, affecting the muscles innervated by the radial nerve.### Upper Limb Nerves, Dermatomes, and Myotomes

Dermatomes of the Upper Limb:
- C5: sensation of skin of anterior/lateral arm
- C6: sensation of anterior skin of thumb
- C7: sensation of anterior skin of digits 2 and 3
- C8: sensation of skin of digits 4 and 5
- T1: sensation of skin of antero-medial elbow
Myotomes of the Upper Limb:
- C5: abduction of the arm at the shoulder (deltoid muscle)
- C6: flexion of the arm at the elbow (biceps)
- C7: extension of the arm at the elbow (triceps)
- C8: finger flexion (small muscles of the hand)
- T1: finger abduction (finger abductors)

Muscle Innervation

Axillary Nerve:
- Origin: terminal branch of posterior cord
- Function: motor to lateral shoulder (deltoid and teres minor)
- Sensory: skin of lateral shoulder
Radial Nerve:
- Origin: terminal branch of posterior cord
- Function: motor to extensor muscles of posterior arm and forearm
- Sensory: posterior arm, forearm, and hand
Median Nerve:
- Origin: terminal branch of lateral and medial cords
- Function: motor to muscles of anterior forearm and hand
- Sensory: palmar surface of digits 1, 2, 3, and lateral 3.5 digits
Ulnar Nerve:
- Origin: terminal branch of medial cord
- Function: motor to medial forearm and hand
- Sensory: palmar and dorsal surface of medial 1.5 digits
Musculocutaneous Nerve:
- Origin: terminal branch of lateral cord
- Function: motor to anterior arm (coracobrachialis, biceps, and brachialis)
- Sensory: skin of anterolateral forearm

Cutaneous Supply from Brachial Plexus

Median Nerve: palmar surface of lateral 3.5 digits
Ulnar Nerve: palmar and dorsal surface of medial 1.5 digits
Radial Nerve: dorsal surface of lateral 3.5 digits

Spinal Nerves

31 pairs of spinal nerves exit the spinal cord
Spinal nerves are white matter pathways for motor and sensory signals between PNS and CNS
Spinal nerves are ipsilateral and carry signals to and from targets/receptors on the same side of the body

Brachial Plexus

Supraclavicular Branches:
- Branches that exit the brachial plexus superior to the clavicle
- Located in the cervical region
- Important branches: Long Thoracic Nerve, Suprascapular Nerve, Dorsal Scapular Nerve
Infraclavicular Branches (Terminal Branches):
- Branches that exit the brachial plexus inferior to the clavicle
- Located in the axilla/arm pit
- Important branches: Musculocutaneous Nerve, Axillary Nerve, Radial Nerve, Median Nerve, Ulnar Nerve### Elbow Joint
The elbow joint is a synovial hinge joint with one degree of freedom.
It consists of three bony articulations: humero-ulnar, humero-radial, and proximal radio-ulnar joints.
The elbow joint permits flexion and extension movements.
It is a very strong joint structurally due to the bony configuration and the collateral ligaments.

Elbow Joint Articular Surfaces & Capsule

The distal end of the humerus has two articular surfaces: trochlea and capitulum.
The elbow joint capsule is a single joint capsule that surrounds the three bony articulations.

Elbow Joint AROM & PROM

The position of reference is defined as the position achieved when the axes of the arm and forearm are in a straight line.
The range of extension is 0°, except in subjects with great laxity of the ligaments, who may have hyperextension of 5° to 10°.
Active flexion has a range of 145°, and passive flexion has a range of 160°.

Proximal (Superior) Radio-Ulnar Joint

This joint is a synovial pivot joint with cylindrical surfaces and one type of movement: rotation about the axis of the two cylinders in contact.
It consists of the head of the radius and the radial notch of the ulna.
The annular ligament is a strong fibrous band that stabilizes the joint.

Articular Complex of the Wrist

The articular complex of the wrist is comprised of three components: radio-carpal joint, mid-carpal joint, and intercarpal joints.
The radio-carpal joint is a condyloid (ellipsoid) joint with an anterior-posterior axis and a transverse axis.
The ligaments of the radio-carpal joint are arranged in two groups: collateral ligaments and anterior and posterior ligaments.

Radiocarpal Joint AROM

The range of abduction and adduction is minimal when the wrist is fully flexed or extended, because of the tension developed in carpal ligaments.
The range of abduction and adduction is maximal when the hand is in the plane of reference or slightly flexed.

Muscle Actions

Extension of the elbow depends on the triceps brachii muscle.
Flexion of the elbow depends on the biceps brachii, brachialis, and brachioradialis muscles.
The biceps brachii muscle is also the main supinator of the forearm.

Cerebral Cortex

The cerebral cortex is divided into primary sensory areas, primary motor area, and association areas.
The primary sensory areas receive and interpret sensory information from the body.
The primary motor area is responsible for controlling voluntary movements.
The association areas integrate sensory information and motor responses.

Functional Areas of the Cerebral Cortex

The primary sensory areas include the primary somatosensory area, primary visual area, primary auditory area, primary gustatory area, and primary olfactory area.
The primary motor area is located in the precentral gyrus and is responsible for controlling voluntary movements.
The association areas include the premotor area, supplementary motor area, and sensory association areas.

Meninges

The meninges are three membranes of connective tissue that surround and protect the CNS.
The dura mater is the outermost layer, the arachnoid mater is the middle layer, and the pia mater is the innermost layer.
The dura mater is a thick layer of dense connective tissue that attaches to the inner surface of the neurocranium.
The arachnoid mater is a delicate layer of connective tissue that contains cerebrospinal fluid (CSF).
The pia mater is a thin layer of connective tissue that is intimately attached to the surface of the brain and spinal cord.

Cerebral Ventricles

The cerebral ventricles are cavities within the brain that contain CSF.
The cerebral ventricles develop from the embryonic neural tube.
The caudal part of the neural tube forms the spinal cord, while the cephalic part forms the cerebral vesicles.
The lumen of the neural tube in the brain is larger and develops into cerebral ventricles.

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Description

This quiz is based on the content covered in BMS Anatomy Lecture 7, focusing on the introduction to upper limb compartments, arm muscles, and anterior forearm muscles. The material is presented by Dr. K. Lumsden and Dr. M. Doroudi at different campuses, referencing Moore's Clinically Oriented Anatomy, 9th edition.