18 Flashcards
What is the general function of the upper limb
- upper limb is designed for mobility to maximise mechanical and sensory function of the hand
- large range of motion and hand actions (power,hook and precision grip, pushing with palm, using fist etc)
- proximal (larger) muscles position the hand (much more mobile then lower limb)
- distal (smaller) muscles for fine motor movement
Joints and region of the upper limb
- shoulder
- elbow
- wrist
- hand and fingers
Compartments of the arm
- anterior and posterior
Compartments of the forearm
Anterior
Posterior
Blood supply of the arm
The subclavian artery becomes the axillary artery as it passes across the lateral border of the first rib
Main blood supple of the muscles of the arm:
- anterior compartment: brachial
- posterior compartment: deep brachial
Deep veins run parallel with the arteries and have the same name as the arteries
Blood supply of the forearm and hand
The brachial artery devides just below the elbow joint into radial and ulnar arteries
Main blood supply of the muscles of the forearm:
- anterior compartment: radial and ulnar
- posterior compartment: posterior interosseous (branch of the ulnar artery)
Main blood supply of the hand
- superficial palmar arch
- deep palmar arch
Veins of the upper limb
- cephallic vein (drains lateral aspect)
- basilic vein (drains medial)
What is a venepuncture
- often used for blood collection or intravenous fluid/drug administration
- commonly done through the median cubical vein (MCV)
- MCV connects the basilica vein and the cephalic vein
Three plexuses in the body:
- cervical: supplies the neck
- brachial: supply’s the upper limb
- lumbosacral: supplies lower limb (derived from the anterior rami of L1- S4)
Brachial plexus innervates the..
Upper limb
What is the brachial plexus formed from?
The anterior ramifications of C5-T1
Main branches of the brachial plexus
- axillary
- radial
- musculocutaneous
- median
- ulnar
What does the axillary nerve supply?
The deltoid and teres minor
What does the radial nerve supply?
Posterior compartment of the arm
Posterior compartment of the forearm
What foes the musculocutaneous nerve supply
Anterior compartment of arm
What is in the anterior compartment of the arm
BBC
- biceps brachii
- brachialis
- coracobrachialis
What does the median and ulnar nerves supply?
Anterior compartment of forearm (mostly median nerve)
Intrinsic muscles of the hand (mostly ulnar nerve)
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Bones of the pectorial girdle
Scapular and clavicle
What do the Soft tissues of the pectorial girdle act to do
Ligaments: limit movement, provide stablility
Muscles: mobility and stability
Functions of the pectorial girdle
- attaches upper limb to axial Skelton
- joints allow scapula to undertake small adjusting movements to keep scapula in contact with thoracic wall
Key points on the clavicle
Clavicle fracture
- easily fractured
- commonly due to force from falling onto outstretched limb
- medial fragment is pulled superiorly by sternocleidomastoid
- lateral fragment drops becuase of gravity (may also be pulled medically by pectoral is major
Key points on the scapular anterior view
Kwy points on the scapular (posterior view)
What kind of joint is the sternoclavicular joint
Synovial, saddle joint
Boney and other components of the sternoclavicular joint
Bony components:
- medial end of clavicle
- manubrium of sternum
- costal cartilage 1
Joint capsule
Ligaments
Intra-articular disc (improves the congruencey between boney ends and helps with shock absorbtion
Stable joint
What kind of movement is allowed at the sternoclavicular joint
- biaxial movement
- movement in two planes
Important ligaments of the sternoclavicular joint and what movement does it restrict?
Costoclavocualr ligament
- hold clavicle down - stop vertical movement
Acromioclavicualr joint
- relatively unstable in comparison to costoclavocular ligament
What kind of joint is the acromioclavicualr joint?
- synovial, plane joint
Boney components of the acromioiclavicular (AC) joint
- acromion (of scapula)
- lateral end of clavicle
Featues of the acromioiclavicular (AC) joint
- joint capsule (weak)
- capsular ligaments
- intra-articular disc
Three key ligaments at the AC joint
- Coracoclavicualr
- Acromioclaviculat
- Coracoacromial
What movements do the ligaments (1. Coracoclavicualr
2. Acromioclaviculat 3. Coracoacromial) in the AC joint prevent
- stop it from moving upwards
- stops it from displacing laterally
What does aromioclavicuar ligament do?
Weak capsular ligaments
- stops chromium and clavicuar separating horizonaltlly
What movement does coracovlavicular joint restrict
- upwards
- lateral discplacemtn
What does the caracoacromial ligament do?
Joins caracoid process and the chromium and caracoid
- stops hemeral head from going upwards
AC joint dislocation
Common in contact sports
Actions of the glenohumeral joint - movements
What kind of joint ids the glenohumeral joint
- synovial, ball and socket
Bony components of the glenohumeral joint
- head of the humerus
- glenoid fossa of the scapula
What kind of range of movement is at the glenohumeral joint ?
Large range of movement due to disproportion (4:1) between the humeral head and glenoid fossa
What percent of the humeral head is in contact with the fossa
25-30
What structures stabilise the glenohumeral joint?
- joint capsule
- glenohumeral ligaments
- glenoid labrum (increases concavity)
- rotator cuff muscles
Features of the capasule of the glenohumeral joint
- attaches to glenoid and anatomical neck of humerus
- lax inferiorly
- reinforced by glenohumeral ligaments and rotator cuff tendons
What aspect of the glenohumeral joint is reinforced the most by ligaments? Why
Supported anteriorly but not posteriorly
- allows us to elevate our arm - full range of movement
Glenohumeral joint dislocation
