Upper limb

Question 1

General features and classification of bones. Types of ossification.

Answer 1

Bone is a rigid and strong connective tissue.
classification of bones:
long, short, flat, irregular, sesamid, sutural, and Pneumatized
Types of ossification: Ossification is the process by which bone is formed. there are two types:
Intramembranous ossification: direct bone formation, development of bone from connective tissue, mesenchymal cells develop via osteoblasts into
osteocytes, osteoclasts develop and collagen fibres
appear, membranous bone is remodeled into lamellar bone ex: skull, facial bones
Endochondral ossification: Endochondral ossification is the process of bone formation in which cartilage scaffolds, arranged in zones, are gradually replaced by bone. there are 5 zones:
① Resting Zone
A. chondrocytes are present in hyaline cartilage
② Proliferative Zone
A. chondrocytes divide & arrange parallely
③ Hypertrophic Zone
A. swollen chondrocytes & the glycogen in their cytoplasm are present
④ Calcification Zone
A. chondrocytes die & ECM calcifies here
⑤ Ossification Zone
A. lack of the chondrocytes
B. bone tissue presented

Question 2

Connections between bones. Classification and general description of
joints.

Answer 2

The places where bones are joined together are called joints.
There are three types of joints:
1. Fibrous (skull)
2. Cartilaginous (vertebra)
3. 3. synovial. (Glenohumeral joint)
types of joints:
Saddle, Condyloid, Gliding, Ball and Socket, Pivot, and hinge

Question 3

General features of skeletal muscles and fasciae. Types of muscles.
Innervation and regeneration of muscles.

Answer 3

Types of muscles:
Skeletal, Cardiac, and smooth
Skeletal muscles are composed of striated muscle fibers that are attached to bones by tendons. They are responsible for voluntary movements, posture, and heat production.
Muscle fasciae are connective tissue layers that surround and separate the muscles and their components. They provide support, protection, and stabilization for the muscles and other structures.
Muscle fasciae can be classified into two types: superficial fascia and deep fascia. Superficial fascia is located under the skin and contains fat, blood vessels, and nerves. Deep fascia is dense and organized and covers the muscles, bones, nerves, and blood vessels.

Muscle regeneration is the process by which damaged skeletal, smooth or cardiac
muscle undergoes biological repair and formation of new muscle in response to death
(necrosis) of muscle cells.
1.Necrosis required for muscle regeneration.
2.Inflammation essential to remove necrotic tissue and initiate myogenesis.
3.re vascularisation New blood vessel formation is required after major injury of muscles.
4.Innervation essential for functional recovery of skeletal muscle.
5.myogenesis where new muscle is formed
* Skeletal muscle contains numerous ‘satellite cells’ underneath the basal lamina, these are
mononucleated quiescent cells.
* When the muscle is damaged, these cells are stimulated to divide.
* After dividing, the cells fuse with existing muscle fibres, to regenerate and repair the
damaged fibres.

Question 4

Biomechanics of the muscle lever functions. Structural and functional
features of myo- and osteotendinous junctions, tendon sheaths.

Answer 4

Lever Systems in the Body: Our bodies are composed of a variety of synovial joints that function as lever systems. A lever system is made up of three parts: an effort, a fulcrum, and a load.
Effort: This is the force applied to the lever, provided by the muscle’s applied force at the insertion site of a bone.
Fulcrum: This is the joint axis.
Load: This is the body part or weight to be moved
Tendon sheath
1. A tendon sheath is a membrane that wraps around a tendon
2. allows the tendon to stretch and prevents it from adhering to the overlying fascia.
3. This sheath also produces a fluid, the synovial fluid, which keeps the tendon moist and
lubricated.
4. Tendon sheaths consist of two layers:
1. fibrous layer, made of tight collagenous tissue
2. synovial layer which consists of a visceral and parietal layer separated by synovial
fluid.
5. There are also fibrous bands, known as retinacula, which make a tunnel around the tendons. The tendon sheaths are located between these two structures and thus prevent friction between them.

The osteotendinous junction - enthesis - tendon insertion site
1. is the site of connection between tendon and bone
2. provides a gradual transition from tendinous to bone
tissue.
3. The enthesis is divided into four zones:
1. zone one, starting at the tendon side, consists of aligned collagen I fibers and
decorin, and exhibits tendon properties only.
2. The second zone contains collagen types II and III, aggrecan and decorin,
resembling fibrocartilage composition.
3. Zone three is defined as mineralized fibrocartilage and is comprised of collagen
types II and X and aggrecan.
4. zone four is composed of mineralized collagen type I and is considered to be a
bone protrusion, providing a dedicated connection point.

Myotendinous junction
1. is the site of connection between tendon and muscle.
2. the force generated by muscle contraction is transmitted from intracellular
contractile muscle proteins to the extracellular connective tissue proteins of the
tendon.
3. At the site of connection, tendon collagen fibrils are set within deep processes that
are formed on the surface of the muscle cells.
4. The main components of the myotendinous junction:
1. Laminin
2. Integrin
3. Vinculin
4. Fibronectin
5. talin, which enable a strong connection between the muscle actin filaments and
the tendon collagen fibers.
5. myotendinous junction is the weakest element of the muscle-tendon complex,
making it susceptible for injury.

Question 5

The bones, joints and movements of the shoulder girdle. Radiological
anatomy of the shoulder girdle.

Answer 5

The shoulder girdle is composed of two bones: clavicle & scapula.

Sternoclavicular joint:
plane synovial joint
Ligaments:
1. Interclavicular ligament.
2. Anterior & posterior sternoclavicular ligament.
3. Costoclavicular ligament.
Movements:
1. Elevation-depression.(Frontal plane, saggital axis)
2. Protraction-retraction.(transverse plane, vertical axis)
3. Rotation.(axis of clavicle) 4. Circumduction.

Acromioclavicular joint:
plane synovial joint.
Ligaments:
1. Acromioclavicular ligament.
2. Coracoclavicular ligaments
Movements:
1. Elevation
depression.
2. Protraction-retraction.
3. Rotation.
4. Circumduction.

Question 6

The gross and radiological anatomy and movements of the shoulder joint and the
participating muscles. The morphological features and biomechanics of the rotator
cuff.

Answer 6

Glenohumeral joint
Type: ball and socket synovial joint
Ligaments:
1. Coracohumeral ligament.
2. Coracoacromial ligament.
3. Glenohumeral ligament.
Movements:
1. Flexion: Deltoid, pec major, coracobrachialis, Biceps Brachii
Extention: Latissimus dosi, Teres Major
2. Abduction: deltoid, supraspinatous
adduction: pec major, pec minor, deltioid, Latissimus dosi, coracobrachialis
3. Rotation.(around the axis of the arm from humeral head to capitulum).
Deltoid, Subscapilaris, teres major- minor, latissimus dorsi, infraspinatus
4. Circumduction.

Rotator cuff:
supraspinatus, infraspinatus, teres minor, subscapularis
These individual muscles combine at the shoulder to form a thick “cuff” over this joint. The rotator
cuff has the important job of stabilizing the shoulder as well as elevating and rotating the arm. Since
the joint capsule and ligaments are weak.

Question 7

The gross and radiological anatomy and movements of the elbow joint
and the participating muscles

Answer 7

Bones of the elbow joint: Humerus, Radius, Ulna
The elbow joint consists of 3 joints:
humeroulnar joint
Type of joint: hinge synovial joint
humeroradial joint
Type of joint: ball and socket synovial joint
proximal radioulnar joint
Type of joint: pivot synovial joint
Ligaments of elbow joint:
1. ulnar collateral ligament
2. radial collateral ligament
3. annular ligament of radius
Muscles:
Flexion: Biceps Brachii, Brachialis
Extension: Triceps brachii, anconeus
pronation: pronator teres and quadratus
supination: supinator, biceps brachii

Question 8

Pronation and supination in the forearm: participating joints and
muscles.

Answer 8

Movements in which the upper end of the radius nearly rotates within the annular ligaments.

Pronation: medial rotation, the shafts of the radius and ulna cross each other, palm face backward. pronation: brachioradialis, pronator quadratus, pronator teres

Supination: lateral rotation, the shafts of radius and ulna lie parallel to one another, palm face forward supination: biceps brachii, brachioradialis, supinator.

Participating joints:
Proximal and distal radioulnar joint: (pivot)
interosseal membrane: (syndesmosis)

Question 9

The gross and radiological anatomy and movements of the wrist joint and the
participating muscles

Answer 9

The wrist joint (radiocarpal joint) is an ellipsoid type synovial joint. formed by
* Distally – The proximal row of the carpal bones (except the pisiform).
* Proximally – The distal end of the radius, and the articular disk
The four ligaments responsible for maintaining the stability of the joint are the palmar and dorsal radiocarpal ligaments and the ulnar and radial collateral ligaments.

The Wrist Joint flexor/ extensor Retinaculum holds nerves, blood vessels and tendons together

movements of the wrist joint and the participating muscles
Palmer flextion: Flexor carpi ulnaris- radialis, flexor digitorum profundus- superficialis, brachioradialis, palmaris longus

Dorsal flextion: extensor carpi radialis longus- brevis
extensor carpi ulnaris, extensor digitorum

radial deviation: extensor carpi radialis longus- brevis, Flexot carpi radialis

ulnar deviation: flexor and extensor carpi ulnaris

Question 10

Joints and movements of the hand. Radiological anatomy of the hand.

Answer 10

Intercarpal joints
* synovial joints formed
between:
1. the bones of the proximal row of the carpal bones which are the scaphoid,
lunate, triquetral and pisiform
2. between the individual bones of the distal row of carpal bones which are
the trapezium, trapezoid, capitate and hamate
3. between the proximal and distal rows (note: small gliding movement)

Carpometacarpal joint
* synovial joints
* Between the distal carpal bones and the metacarpals, and the intermetacarpal joints
are between the metacarpals

Carpometacarpal joint of the thumb
* saddle-shaped joint
* Formed between the trapezium and the base of the first metacarpal.
* The joints have a synovial membrane surrounded by fibrous joint capsules.
The fifth metacarpal joint is fairly mobile, but
the rest don’t have much movement.

Each finger has 2 joints
Metacarpophalangeal (MCP) joints
* condyloid joints
* Formed by the articulation between metacarpal and proximal phalanx in each of
the 5 digits.
Interphalangeal Joints: which breaks into proximal and distal (only in digits 2-5)
* Hinge joints “Ginglymus”
* Formed by the phalanges
* There are two in each digit. The thumb is an exception, and has only one interphalangeal joint.

Movements:
* Flexion of digits : can be performed at each MCPJ, PIPJ and DIPJ and brings the
hand into a fist.
* Extension of digits: can be performed at each MCPJ, PIPJ and DIPJ and stretches the
hand out straight.
* Abduction of digits : moving the digits away from the midline.
* Adduction of digits – moving the digits back toward the midline.
* Opposition of thumb and little finger: bringing the thumb and little finger
together.
* Reposition of thumb and little finger: moving the thumb and little finger away from each other.

Question 11

The anatomy, innervation and function of the spinohumeral and thoracohumeral
muscles.

Answer 11

Spinohumeral muscles
1. Levator scapulae
* Action:
1. Draws the scapula medially upward while moving the inferior angle medially
2. Bends the neck laterally
* Innervation
Dorsal scapular nerve C5
Cervical spinal nerve C3 - C4

2. Trapezious
   * Action:
   Upper Part:
3. Upward rotation of the scapula
4. elevation of the scapula Middle Part:
5. Retraction of the scapula
   Lower Part:
6. Upper rotation of the scapula
7. depression of the scapula
   * Innervation: Spinal Accessory Cranial XI , Ventral Rami C2-C4
8. Rhomboid minor/major
   * Action
9. Steadies the scapula
10. Draws the scapula medially upward - elevate and adduct scapula
11. Rotate the scapula downward
    * Innervation: Dorsal scapular nerve C4 - C5
12. Latissimus dorsi
    Action: Extension, adduction, Internal rotation
    Innervation: Thoraco dorsal nerve C6-C8

Thoracohumeral muscles:
1. Pectoralis major
* Function
1. Flexion,
2. Adduction
3. internal rotation of arm
4. Assists in respiration when limbs fixed
* Innervation: pectoral nerves (medial and lateral)

2. Pectoralis minor
   * Function
3. pulls the scapula anteriorly and inferiorly toward the ribs (abduction and
   depression)
4. Rotates the glenoid inferiorly
5. Assists in respiration
   * Innervation: medial and lateral pectoral nerves C8 - T1
6. Subclavius
   * Function
7. depression of clavicle
8. Steadies the clavicle in the sternoclavicular joint
   * Innervation: subclavian nerve C5 - C6
9. Serratus anterior
   * Function 1. Entire muscle:
   * Draws the scapula laterally forward
   * Elevate the ribs
   * Assist in respiration (when limb is fixed)
10. Inferior part:
    * Rotate the scapula and draws its inferior angle laterally forward allowing the arm to be elevated above 90 degrees
11. Superior part:
    * Lowers the raised arm
    * Innervation: long thoracic nerve C5 - C7

Question 12

Classification (types) and innervation of medium and large blood vessels. Types
of vascular anastomoses.

Answer 12

Three types of blood vessels
Atreries, veins, capillaries.

Classification (types)
1. Conducting vessels: aorta, pulmonary trunk.
2. Distributing vessels (subclavian a.,axillary a., brachial a.)
3. Resistance
vessels: small muscular arteries and arterioles.
4. Exchange vessels: capillaries, venules.
5. Reservoir vessels: veins.

Innervation of blood vessels
nerves endings found in the tunica adventisa
1. sensory nerves: receptors for pressure and the composition of blood
2. Effector nerve: release norepinephrine as transmitter cause
smooth muscle contraction in vessel wall vasoconstriction

Types of vascular anastomoses:
1. Arterio-venous (a-v) anastomoses - directly connect arterioles and venules
2. Arterio-arterial (a-a) anastomoses

Question 13

The systemic circulation: the large branches of the aorta and the great
veins.

Answer 13

• Return of Blood from the Upper-Body:
  Blood returns from the head via the jugular veins, and from the arms via the subclavian veins. All
  of the blood in the major veins of the upper body flows into the superior vena cava, which
  returns the blood to the right ventricle of the heart.
• Return of Blood from the Lower-Body:
  Blood returns from the small intestines by passing through the hepatic portal vein to the
  liver. Blood returns from the liver via the hepatic vein, from the kidneys via the renal veins,
  and from the legs via the iliac veins. All of the blood in the major veins of the lower body
  flows into the inferior vena cava, which returns the blood to the right ventricle of the heart.

Question 14

The branches and anastomoses of the axillary artery

Answer 14

Circumflex Humeral Arteries
Finally, the third part of the axillary artery gives off an anterior and a posterior circumflex
humeral artery (ACHA & PCHA, respectively). The ACHA is the smaller of the two arteries. It
travels in a horizontal manner towards the surgical neck of the humerus, deep to the short
head of biceps brachii and coracobrachialis. At the intertubecular groove, it gives a branch
that travels superiorly in the sulcus to supply the glenohumeral joint.

Question 15

The branches of the brachial artery; collateral circulation of the elbow.

Answer 15

Branches:
1. Muscular branches: It supplies all the muscles of arm directly or through its branches.
2. Nutrient artery to the humerus
3. Deep artery of the arm (Profunda brachii artery): Profunda brachii artery arises from
medial and posterior part of brachial artery as a large branch just below the lower
border of teres major muscle. It closely follows the radial nerve and passes between
the lateral and medial heads of triceps muscle. After passing through the radial grove
of humerus along the radial nerve, it pierces the lateral intermuscular septum and
reaches the front of lateral epicondyle of humerus. It ends by anastomosing with the
radial recurrent artery.
Profunda brachii artery supplies the deltoid muscle (which is primarily supplied by the
posterior circumflex humeral artery) and occasionally also gives an unusual nutrient artery to
the humerus. At its end, it takes part in the formation of anastomoses around elbow joint.
4. Superior ulnar collateral artery: It is a small sized artery arising from the brachial
artery just below the middle of the arm. It pierces the medial intermuscular septum of
the arm and reaches behind the medial epicondyle of humerus. It ends by taking part
in anastomoses around the elbow joint.
5. Inferior ulnar collateral artery: It arises from brachial artery about two and half inches
above the elbow joint. Near its origin it pierces the medial intermuscular septum and
reaches behind the medial epicondyle of humerus. It ends by taking part in
anastomoses around the elbow joint.
6. Radial artery
7. Ulnar artery

Question 16

Topography and branches of the palmar arterial arches.

Answer 16

Anatomical layers on the palm:
1. Skin
2. palmar aponeurosis
3. superficial palmar arch and common digital nerves
4. flexor tendons and lumbrical muscles
5. deep palmar arch, deep branch of the ulnar nerve
6. interosseus muscles and adductor pollicis muscle
Superficial palmar arch
* formed predominantly by:
o ulnar artery o superficial palmar branch of the radial artery. o in some individuals the
contribution from the radial artery might be absent, and instead anastomoses with either
the princeps pollicis artery, the radialis indicis artery, or the median artery, the former
two of which are branches from the radial artery.
* Is Covered by the palmar aponeurosis
* The superficial arch gives the arteries supplying four fingers (II-V)
* Common palmar digital arteries (3)
* Proper palmar digital arteries (6)
* A. digitalis propria (1) for the small finger
* the superficial palmar arch is completely formed only in 27 % of cases. It is unclosed in a majority of cases.

Deep palmar arch
* located Beneath the long flexor tendons
(deepest layer of the palm)
* Radial artery (end-branch)
* Deep palmar branch of the ulnar artery
Branches:
* Palmar metacarpal arteries (4)
* Perforant branches to the superficial arch
Important branches of the radial artery before it
joins to the deep arch:
* Princeps pollicis artery: supplies the thumb
(2 digital arteries)
* Radial indicis artery: supplies the radial side
of the index finger
Anastomosis:
Arcus palmaris superficialis & profundus.
Arcus dorsalis: dorsal carpal arch (weak) on the back of the wrist and hand.

Question 17

The venous and lymphatic drainage of the upper limb.

Answer 17

Deep veins:
* accompany all of the major arteries of the arm, and drain blood from the dorsal and plantar arches to the vessels accompanying the radial and ulnar arteries. These continue to the cubital fossa, where they unite to form vena comitantes of the brachial vein. These vena comitantes merge with the basilic vein in the axilla to form the axillary vein. The major superficial veins of the upper limb are the cephalic and basilic veins., they are located within the subcutaneous tissue of the upper limb. The basilic vein originates from the dorsal venous network of the hand. It ascends the medial aspect of the upper limb. At the border of the teres major, the vein moves deep into the arm. Here, it combines with the brachial veins to form the axillary vein. The cephalic vein arises from the dorsal venous network of the hand. It ascends the antero-lateral aspect of the upper limb, passing anteriorly at the elbow. At the shoulder, the cephalic vein travels
between the deltoid and pectoralis major muscles (known as the deltopectoral groove), and enters
the axilla region via the clavipectoral triangle. Within the axilla, the cephalic vein terminates by joining the axillary vein. At the elbow, the cephalic and basilic veins are connected by the Superficial Lymphatic Vessels median cubital vein

Superficial Lymphatic Vessels
median cubital vein .The superficial lymphatic vessels of the upper limb initially arise from lymphatic plexuses in the skin of the hand (networks of lymphatic capillaries beginning in the extracellular spaces). They then ascend up the arm, in close proximity to the major superficial veins:
* The vessels shadowing the basilic vein go on to enter the cubital lymph nodes. These are found medially to the vein, and proximally to the medial epicondyle of the humerus. Vessels
carrying on from these nodes then continue up the arm, terminating in the lateral axillary lymph nodes.
* The vessels shadowing the cephalic vein generally cross the proximal part of the arm and shoulder to enter the apical axillary lymph nodes, though some exceptions instead enter the
more superficial deltopectoral lymph nodes.

Deep Lymphatic Vessels
The deep lymphatic vessels of the upper limb follow the major deep veins (i.e. radial, ulnar and brachial veins), terminating in the humeral axillary lymph nodes. They function to drain lymph from joint capsules, periosteum, tendons and muscles. Some additional lymph nodes
may be found along the ascending path of the deep vessels. Lymph Nodes The majority of the upper lymph nodes are located in the axilla. They can be divided anatomically into 3 levels: Level I ( lateral to pectoralis minor)
* Pectoral (anterior) – 3-5 nodes, located in the medial wall of the axilla. They receive lymph
primarily from the anterior thoracic wall, including most of the breast.
* Subscapular (posterior) – 6-7 nodes, located along the posterior axillary fold and subscapular
blood vessels. They receive lymph from the posterior thoracic wall and scapular region.
* Humeral (lateral) – 4-6 nodes, located in the lateral wall of the axilla, posterior to the axillary
vein. They receive the majority of lymph drained from the upper limb.
* Para mammary
Level 2 (along pectoralis minor)
* Central – 3-4 large nodes, located near the base of the axilla (deep to pectoralis minor, close
to the 2nd part of the axillary artery). They receive lymph via efferent vessels from the pectoral, subscapular and humeral axillary lymph node groups.
* Interpectoral
Level 3 (medial to pectoralis minor)
* Apical – Located in the apex of the axilla, close to the axillary vein and 1st part of the axillary
artery. They receive lymph from efferent vessels of the central axillary lymph nodes, therefore
from all axillary lymph node groups. The apical axillary nodes also receive lymph from those
lymphatic vessels accompanying the cephalic vein. Efferent vessels from the apical axillary nodes travel through the cervico-axillary canal, before converging to form the subclavian lymphatic trunk. The right subclavian trunk continues to
form the right lymphatic duct, and enters the right venous angle (junction of internal jugular
and subclavian veins) directly. The left subclavian trunk drains directly into the thoracic duct.

Question 18

The organization of spinal cord segments and spinal nerves. The general organization
and features of the cranial nerves.

Answer 18

The spinal cord is a long, thin, tubular bundle of nervous tissue and support cells that extends from the medulla oblongata in the brainstem to the lumbar region of the vertebral column. In humans, the spinal cord begins at the occipital bone where it passes through the foramen magnum, and meets and enters the spinal canal at the beginning of the cervical vertebrae. The spinal cord extends down to between the first and second lumbar vertebrae where it ends, and keep runs as a cauda equina.

1. Cervical region - 7 vertebras ,8 segments because the first cervical have also above the bone segment and also beneath, all the other the segment are beneath, lordosis
2. Thoracic region - 12 vertebras, 12 segments, kyphosis
3. Lumbar region - 5 vertebras, 5 segments ,lordosis
4. Sacral region – 5 bones ossified to 1, 5 segments, kyphosis
5. Coccygeal region - 3 bones , 1 segment Total 31 segments , 32 vertebras

Spinal cord - - - - -
Encased in bone - in the spinal column
Protected by bone and three meninges:
o Dura mater – outer layer, thick dense fibrous tissue, tightly
connected to the surrounding bone.
o Arachnoid mater – middle, thin layer, provides cushioning effect for the CNS.
o Pia mater – inner most, thin, tightly associated with the brain and spinal
cord. Cushioned by cerebrospinal fluid (CSF) Has a central canal, containing CSF The gray matter is inside and the white mater is outside - Transmits impulses to and from the brain:
o Ascending tracts
Transmit information to the brain ‘afferent’ - sensation, ascends to
the spinal cord by dorsal root
o Descending tracts Transmit the information from the brain ‘efferent’ - motor, descends to the muscle by ventral root Spinal ganglion – a group of cell bodies, next to the spinal cord. Dorsal root – a bunch of sensory axons entering the spinal cord from the back. (afferent nerves)
Ventral root – a bunch of axons carrying motoric messages. (efferent nerves)

Cranial nerve I: the olfactory nerve which permits the sense of smell
Cranial nerve II: the optic nerve, the nerve that connects the eye to the brain and carries the impulses formed by the retina
Cranial nerve III: the oculomotor nerve. The oculomotor nerve is responsible for the nerve
supply to muscles around the eye.
Cranial nerve IV: the trochlear nerve, is the nerve supply to the superior oblique muscle of the eye, one of the muscles that moves the eye.
Cranial nerve V: the trigeminal nerve. The trigeminal nerve is quite complex. It functions
both as the chief nerve of sensation for the face and the motor nerve controlling the muscles of mastication (chewing).
Cranial nerve VI: is the abducens nerve. It is a small motor nerve that has one task: to supply a muscle called the lateral rectus muscle that moves the eye outward.
Cranial nerve VII: The facial nerve is the seventh cranial nerve.The facial nerve supplies the muscles of facial expression.
Cranial nerve VIII: the vestibulocochlear nerve. The vestibulocochlear nerve is responsible for the sense of hearing and it is also pertinent to balance, to the body position sense.
Cranial nerve IX: the glossopharyngeal nerve. The glossopharyngeal nerve supplies the
tongue, throat, and one of the salivary glands (the parotid gland). Problems with the glossopharyngeal nerve result in trouble with taste and swallowing.
Cranial nerve X: The vagus nerve originates in the medulla oblongata, a part of the brain stem. The vagus nerve is a remarkable nerve that relates to the function of numerous
structures in the body. The vagus nerve supplies nerve fibers to the pharynx (throat), larynx (voice box), trachea (windpipe), lungs, heart, esophagus, and most of the intestinal tract. The vagus nerve brings sensory information back from the ear, tongue, pharynx and larynx
Cranial nerve XI: the accessory nerve. The accessory is so-called because, although it arises in the brain, it receives an additional (accessory) root from the upper part of the spinal cord. The accessory nerve supplies the sternocleidomastoid and trapezius muscles
Cranial nerve XII: the hypoglossal nerve. The hypoglossal nerve supplies the muscles of the
tongue. (The Greek “hypo-“, under, and “-glossal” from “glossa”, the tongue = under the tongue).

Question 19

Organization and supply areas of the brachial plexus.

Answer 19

Question 20

Branches of the median nerve, functional loss of the median nerve.

Answer 20

where the medial cord joins the lateral cord you get the median nerve. It contains nerve fibers from all 5 nerve roots C5-T1. The median nerve has both sensory and motor function the median nerve sits lateral to the brachial artery and as it descends further proximally it crosses over to become more medial and sits medial to the brachial artery. the median nerve descending in themedial aspect of the arm alongside the brachial artery it then enters the elbow at the cubital fossa and passes into the anterior compartment of the forearm.the median nerve descending in the medial aspect of the arm alongside the brachial artery it then enters the elbow at the cubital fossa and passes into the anterior compartment of the forearm proximately you’ve got the anterior interosseous nerve and distally you’ve got the palmar cutaneous nerve the anterior
interosseous nerve supplies the deep flexor muscles of the anterior compartment of the arm these muscles include the flexor pollicis longus the pronator quadratus and the lateral half of the flexor digitorum profundus muscle. superficial and intermediate layers in the superficial layer it provides innovation to the pronator teres the flexor carpi radialis and the palmaris longus

the second nerve which arises in the forearm from the median nerve is the palmar cutaneous nerve it passes over the flexor retinaculum this nerve innervates the skin of the lateral palm. the median nerve passing underneath the flexor retinaculum within the carpal tunnel the median nerve can get compressed causing carpal tunnel syndrome this is the most common mono neuropathy and can be caused by thickened ligaments and tendons sheaths. It can cause weakness and atrophy of the thenar muscles in addition you get numbness tingling and sensory changes in the distribution of the median nerve affecting the lateral three and a half digits

Motor: it innovates the flexor muscles in the anterior compartment of the forearm except for the flexor carpi ulnaris and the medial half or ulnar half of the flexor digitorum profundus, (these are innervated by the ulner nerve). within the hand the median nerve supplies innovation to the thenar
muscles and the lateral to lumbricals.

Sensory: the median nerve gives rise to a Palmer cutaneous branch which innervates the lateral part of the palm. which is innovated by the palmar cutaneous branch. (three and a half fingers) which are supplied by the digital branches of the median nerve.

Question 21

Branches of the ulnar nerve, functional loss of the ulnar nerve.

Answer 21

The ulnar nerve is a major peripheral nerve of the upper limb it’s derived from the brachial plexus and is a continuation of the medial cord containing fibers from spinal roots c8 and t1. the ulnar nerve has both sensory and motor functions.

In terms of motor function, it innervates the muscles of the hand apart from the thenar muscles and the two lateral lumbercals which are innervated by the median nerve. in the forearm, the ulnar nerve innervates the flexor carpi ulnaris muscle and the medial half of the flexor digitorum profundus.

in terms of its sensory function it innervates the anterior and posterior surfaces of the medial one and a half fingers and the associated area on the palm of the hand.

the ulnar nerve descends down the medial side of the upper arm to the elbow proximity. at the elbow, it passes posterior to the medial epicondyle to enter the forearm at this point behind the medial epicondyle the ulnar nerve is easily palpable

the ulnar nerve gives rise to three branches, the muscular branches proximally and then you’ve got the palmar cutaneous branch, and the dorsal cutaneous branch distally.

Functional loss of the ulnar nerve.
It depends where the injury occurs
1.proximal ulnar nerve lesion →clinical features: claw hand and sensory disturbance.
2. midlevel ulnar nerve lesion →clinical features: claw hand and sensory disturbance, that
spare the hypothenar region (palmar branch is intact)
3. distal ulnar nerve lesion →clinical features: claw hand and without sensory disturbance (the superficial branch is intact)

Question 22

Branches of the radial nerve, functional loss of the radial nerve.

Answer 22

• Arises from the posterior cord of the brachial plexus.
• After leaving the axilla it spirals posteriorly around the humerus and joins the deep brachial a.
• After piercing the intermuscular septum it re-enters the anterior compartment to pass
  downward and forward between the brachialis m. and brachioradialis m.
  Then it gives rise to the deep and superficial branches.
  Superficial branch:
• Descends alongside the ulnar border of brachioradialis m.
• In the middle-third of the forearm it runs together with the radial artery.

functional loss of the radial nerve. Wrist drop due to proximal and midlevel radial nerve lesions. When the radial nerve is damaged, the patient can no longer actively extend the hand at the wrist, and wrist drop (drop hand) is said to be present. Besides the dropped position of the wrist, clinical examination reveals areas of sensory loss on the radial surface of the dorsum and on the extensor surface of the thumb, index finger, and the radial half of the middle finger extending to the proximal interphalangeal joint. The sensory deficits are often confined to the area of the hand that receives sensory innervation exclusively from the radial nerve (the interosseous space between the thumb and index finger). Additional sign: weakness of thumb finger extension.

Question 23

Skin innervation of the upper limb.

Answer 23

Question 24

Axillary fossa, triangular and quadrangular axillary spaces.

Answer 24

The walls of the axilla are formed by various muscles and their fascia:
The anterior wall of the axilla consists of the pectoralis major and minor and the clavipectoral fascia.
Posterior wall: this consists of the subscapularis, teres major, and latissimus dorsi muscles.
Lateral wall: this is narrow and formed by the intertubercular groove of the humerus.
Medial wall: this is formed by the lateral thoracic wall (ribs 1-4 and associated intercostal
muscles) and the serratus anterior.

Triangular space
Circumflex scapular artery
* Inferior: the superior border of the teres major;
* Lateral: the long head of the triceps;
* Superior: Teres minor.

Quadrangular space
Posterior circumflex
humeral artery, axillary nerve
* above/superior: the teres minor (inferior margin).[2]
* below/inferior: the teres major (superior margin)
* medially: the long head of the triceps brachii (lateral
margin)
* laterally: the surgical neck of the humerus
* anteriorly: the subscapularis

Question 25

26. Topography of the volar and dorsal wrist regions: tendons, tendon sheaths,
    osteofibrous compartments, vessels and nerves. The carpal tunnel.

Answer 25

Structures that pass through the Carpal tunnel:
1. Median nerve
2. Tendons of flexor digitorum profoundus (4)
3. Tendons of flexor digitorum superficialis (4)
4. Flexor policis longus
* Above carpal tunnel the ulnar nerve and palmaris longus pass to the hand though they DO NOT PASS IN THE TUNNEL.
* Flexor carpi radials pass through the layers of the flexor retinaculum and not in the tunnel
itself.

Dorsal wrist compartment:
osteofibrous compartments:
Extensor tendon compartments of the wrist are anatomical tunnels on the back of the wrist that contain tendons of muscles that extend (as opposed to flex) the wrist and the digits (fingers and thumb). The extensor tendons are held in place by the extensor retinaculum. As the tendons travel over the posterior (back) aspect of the wrist they are enclosed within synovial tendon sheaths.
Compartment 1: Conducts the abductor pollicis longus and the extensor pollicis brevis tendons. These
tendons form the lateral (thumb side) border of the anatomical snuff box.
Compartment 2: Conducts the extensor carpi radialis longus and extensor extensor carpi radialis brevis muscle tendons.
Compartment 3: Conducts the extensor pollicis longus tendon that acts to extend the thumb. It forms the medial (little finger) side of the border of the anatomical snuff box.
Compartment 4: Conducts the extensor digitorum and extensor indicis tendons to the four fingers.
Compartment 5: The extensor digiti minimi tendon travels through this compartment to the little finger.
Compartment 6: Conducts the extensor carpi ulnaris tendon. This muscle both extends and adducts (hand flexes toward the little finger side) the hand.

Question 26

Dorsum of the hand. The anatomical snuffbox (foveola radialis).

Answer 26

The anatomical snuffbox:
➢ Ulnar (medial) border: Tendon of the extensor pollicis longus.
➢ Radial (lateral) border: Tendons of the abductor pollicis longus and extensor pollicis
brevis.
➢ Proximal border: Styloid process of the radius.
➢ Floor: Carpal bones; scaphoid and trapezium.
➢ Roof: Skin.
The structures that run together in the anatomical snuffbox include the cephalic vein, the radial artery, and the superficial radial nerve.

Question 27

Palm of the hand: muscles, fasciae, compartments, vessels and nerves.

Answer 27

muscles: Thenar (thumb)
abductor pollicis brevis, adductor pollicis, opponens pollicis, and flexor pollicis brevis

Hypothenar (pinky)
abductor digiti minimi, flexor digiti minimi brevis, and opponens digiti minimi. All hypothenar muscles are supplied by the ulnar nerve

the interossei muscles (four dorsally and three volarly) originating between the
metacarpal bones All the interossei are supplied by the deep branch of the ulnar nerve

There are 4 lumbricals arising from the radial sides of the tendons of the flexor digitorum profundus.

Palmar aponeurosis :
The central portion occupies the middle of the palm, is triangular in shape, and of great
strength and thickness. May be defines as the thickened, central portion of the deep palmar fascia

Compartments:
* Thenar compartment Contains the thenar muscles.
* Central compartment Contains the flexor tendons and their sheaths, the lumbricals,
the superficial arterial palmar arch, and the digital vessels and nerves.
* Hypothenar compartment Contains the hypothenar muscles.
* Adductor compartment Contains only Adductor Pollicis .
* Interosseous compartments Contains the interossei muscles.

vessels and nerves:
blood supply:
the Ulnar and radial arteries forms two arches in the palm of the hand; the superficial palmar arch and the deep palmar arch.
Superficial palmar arch:
The superficial palmar arch is formed predominantly by the ulnar artery, with a contribution from the superficial palmar branch of the radial artery.
Three common palmar digital arteries arise from the arch, proceeding down on the second, third, and fourth lumbrical muscles, respectively. They each receive a contribution from a palmar metacarpal artery. Near the level of the metacarpophalangeal joints, each common palmar digital artery divides into two proper palmar digital arteries. The deep palmar arch: The deep palmar arch (deep volar arch) is an arterial network found in the palm. It is usually
formed mainly from the terminal part of the radial artery, with the ulnar arterycontributing via its deep palmar branch, by an anastomosis. This is in contrast to the superficial palmar arch, which is formed predominantly by the ulnar artery.
Alongside of it, but running in the opposite direction—toward the radial side of the hand—is the deep branch of the ulnar nerve. From the deep palmar arch emerge palmar metacarpal arteries.

the hand is innervated by 3 nerves: the median, ulnar, and radial. Each has sensory and motor components The skin of the forearm is innervated medially by the medial antebrachial cutaneous nerve and laterally by the lateral antebrachial cutaneous nerve.