Neck and Upper Limb Osteology

cervical plexus

Formed by anterior rami of the first four cervical nerves

covered by the prevertebral layer of deep cervical fascia and related to internal jugular vein within the carotid sheath

Supplies skin and muscles of head, neck and shoulder • Cervical nerve • C1 - C4

segmental

prevertebral muscles, levator scapulae

ansa cervicalis c1,2,3

omohyoid, sternohyoid, sternothyroid

c1 fibers via hypoglossal nerve

thyrohyoid, genohyoid

phrenic nerve c3,4,5

nerve to diaphragm, important for contraction

Thyroid Gland

Consists of right and left lobes and isthmus (level of 2 nd to 4th tracheal ring)

hyoid

c3

thyroid cartilage

c4-5

cricoid

c6

Pyramidal lobe

found in the isthmus more on left

Levator glandulae thyroideae

muscular band connecting the pyramidal lobe to the hyoid

anterolateral Thyroid Gland

Sternothyroid, superior belly of omohyoid, sternohyoid, anterior 2/3 of SCM

medial Thyroid Gland

Larynx, trachea, pharynx, esophagus

Posterolateral Thyroid Gland

Carotid sheath with common carotid artery, internal jugular vein and vagus n

Posterior Thyroid Gland

Superior and inferior parathyroid gland

Anastomosis of inferior and superior thyroid artery

thyroxine and triiodothyronime

increases metabolic activity of most cell in body

Thyrocalcitonin

produced by parafollicular cells that lower the level of blood calcium

Parathyroid

Small ovoid, parathyroid glands lie external to the fibrous thyroid capsul

superior parathyroid gland

lie middle of the posterior border of the thyroid gland and inferior parathyroid glands lie close to the inferior pole of thyroid gland

Trachea

Mobile cartilaginous and membranous tube

Starts as a continuation from larynx ( at level of cricoid, lower border of C 6) and ends at carina (division of the tranchea to principal bronchus) at the level of sternal angle of Louis (between 4th and 5th thoracic vertebrae)

anterior trachea

• Skin, fascia • jugular arch • Isthmus of thyroid (2nd to 4th tracheal rings) • thyroidea ima • Inferior thyroid vein • L bracheo cephalic v • Sternothyroid and sternohyid muscles

posterior trachea

• Esophaus • Right and left recurrent laryngeal nerves

lateral trachea

• Lobes of thyroid gland • Carotid sheath and contents

trachea

Made of U shaped cartilaginous bars of hyaline

Posterior is free

Trachealis muscle

connects free end

Esophagus

Tubular structure 10 inches long

From pharynx to stomach

Continuous above with the laryngeal part of the pharynx opposite 6th cervical vertebra and passes diaphragm at level of 10th thoracic vertebra to join stomach (c6 to t10)

anterior esophagus

• Trachea • Recurrent laryngeal nerve

posterior esophagus

• Prevertebral layer of the cervical fascia; vertebral column and longus colli

lateral esophagus

• Thyroid gland (lobe) and carotid sheath

parasympathetic and sympathetic efferent and afferent fibers, esophageal nerve plexus

nerve of esophagus

root of the neck

Area immediately above the inlet to the thorax

Contents: ■ Subclavian artery ■ Subclavian vein ■ Thoracic duc

Interscalene triangle

gap between scalenus anterior and medius muscle and first rib

Where subclavian artery and roots fo brachial plexus pass through

clavicle

Collar bone • Between sternum and scapula; base of neck • Connected medially to the sternum and laterally to the scapula • S shape

First bone to ossify

strut

__ connecting the upper limb to the thorax and together with scapula, it allows the limb to move freely from the trunk

functions of clavicle

Transmits forces from the upper extremity o Holds arm away from trunk o Provides attachment for muscles o Absorbs force from upper extremity

clavicle

Articulates with costal cartilage and sternum medially and acromion scapula laterally

Medial (sternal extremity) end

Proximal end, blunt, thickened o Attaches to the sternum through Clavicular notch o Forms the Sternoclavicular joint o Convex

Lateral (acromial extremity) end

o Flat o Attached to acromion process of scapula o Concave

clavicle

Origin of deltoid, pectoralis major, SCM

Insertion of subclavius m., upper fibers of trapezius

clavicle

most commonly fractured bone in the body because it absorbs force from upper extremity

anterior clavicle

more smooth

posterior clavicle

rough because this is where ligaments attach

body

Conoid tubercle is found; this is for the attachment of the conoid ligament

Subclavian groove

Where the subclavian vessels will pass through

Costal tuberosity

Attaches to the first rib

scapula

Shoulder bone or shoulder blade • Flat, triangular in shape

• Between 2nd to 7th ribs (ex: 2nd rib attached to T2 and so on)

ventral or costal surface

Concave o Forms shallow subscapular fossa (entire thing) o Nothing divides it

spine

– divides posterior side to supraspinous and infraspinous fossa

Acromion

- free lateral end of spine; articulates with clavicle

Coracoid process

- found above glenoid cavity, for attachment of muscles and ligaments

Suprascapular notch

medial to base of coracoid process

Glenoid cavity

superolateral angle of the scapula; pear shape, articulates with the humeral head (and its attachment site); shallow cavity

Supraglenoid tubercle

Long head of biceps

Infraglenoid tubercle

Long head of triceps

sternum

Flat bone also known as breastbone • Connected to shoulder girdle • Medial area where clavicle attaches

clavicular facets

connects the clavicle to sternum; where clavicle is attached

costal facets

where 1st rib is attached o Jugular notch/ Suprasternal notch

body

Where 2nd to 7th rib attaches to

Xiphoid Process

8th to 10th will join to be the angle and will attach to the 7th rib

Sternal angle of Louis

Junction of body and manubrium o Cartilaginous joint o Between Intervertebral disc of T4-T5

Sternal angle of Louis

marks the superior level of the pericardium, the sac enclosing the heart, and the superior limit of the pulmonary trunk

Shows the level of the beginning and end of the arch of the aorta

is the level at which the trachea bifurcates into right and left main bronchi

Sternal angle of Louis

o marks the site of articulation of rib 2 with the sternum o Boundary between the superior and inferior portion of the mediastinum o Passage of the thoracic duct from right to left behind esophagus o End of the azygos system into SVC

humerus

Articulates with the scapula (glenoid fossa) to form the shoulder joint and radius and ulna at the elbow joint • Forms glenohumerus joint/main shoulder joint • Longest bone in the UE

head

1/3 of a sphere, articulates with glenoid fossa (because glenoid is very shallow and why dislocated shoulders are common); contains the greater and lesser tuberosities which are divided by an intertubercular notch/groove

surgical neck

- area where fracture is most common

Deltoid tuberosity

- attachment/insertion of deltoid

spiral groove

- accommodates the radial nerve

Deltoid tuberosity

rough triangular elevation for attachment of deltoid

Radial groove or spiral groove

posterior shallow depression; between deltoid tuberosity and lateral supracondylar ridge o Radial nerve and profunda brachii vessels

medial epicondyles

sometimes called the funny bone; more prominent than lateral

lateral epicondyle

where radial bone will be attached

Capitulum

round, articulates with radial head; caput

radial notch

above capitulum; where elbow bends, where head of radius goes

trochlea

pulley shape, articulates with trochlear notch of ulna

Coronoid fossa

above trochlea; for the articulation of the coronoid process

Olecranon fossa

receives olecranon process of ulna when elbow is extended

radius

• Lateral bone in the forearm • Articulates proximally with humerus (capitulum) and ulna at (to form proximal radius ulnar joint) • distally, articulates with the scaphoid and lunate bone (to form ellipsoid/wrist joint) and distal ulna (distal radius ulnar joint) • Becomes wider distally

head

small, circular ▪ Concave upper surface articulates with the capitulum of humerus ▪ Circumference articulates with notch of ulna

Bicipital tuberosity

- insertion of biceps

shaft

wider below than above ▪ Interosseous border ▪ Pronator tubercle (insertion of pronator teres muscle)

Interosseous border

where there is an interosseous membrane

Interosseous membrane

forms a fibrous joint connecting the radius to the ulna

fibrous joint

Middle radioulnar joint

pivot joint

Proximal and Distal radioulnar joint

Radial tuberosity

attachment of biceps

Styloid process

projects distally from the lateral margin

Ulnar notch

medial surface for attachment of ulna

Inferior surface

articulates with scaphoid and lunate

Dorsal tubercle (Lister’s tubercle)

- grooved on its medial side by the tendon of the extensor pollicis longus; tendons pass through here

ulna

Medial bone • Articulates with trochlea of humerus at the elbow joint and with head of radius at the proximal radioulnar joint • Becomes narrower distally • Distal end articulates with radius at distal radioulnar joint

Olecranon

forming the prominence of the elbow posteriorly

Trochlear notch

articulates with the trochlea of the humerus

Coronoid process

triangular end below the trochlear notch

Radial notch

articulation of radial head

Supinator crest

– found below the radial notch

8

how many carpal bones

Cartilaginous

__ at birth (carpal bone)

Capitate

__ first to ossify

scaphoid

Most commonly fracture carpal bone is