Limb musculature and innervation Flashcards
What are examples of different skeletal muscle shapes?
Circular muscle
Pennate muscle: fibres that lie diagonally
Parallel muscle: orientated parallel to the line of action
Fusiform muscle: spindle shaped with a belly larger than insertion and origin
Convergent muscle: fan shaped muscle with wide origins and narrow insertions.
What is a bursa?
A fluid filled sac that provides a cushion between bones and tendons and/or muscles around a joint.
What is present on the bursal side of bone and tendon?
Fibrocartilage called the enthesis
Why is the enthesis rough?
Increase surface area of connection.
Describe flexion and extension
Flexion: Decrease in the anterior angle between the bones of the joint.
Extension: Increase in the anterior angle between the bones of the joint.
Describe abduction and adduction
Abduction: Movement away from the midline of the body.
Adduction: Movement towards the midline of the body.
Describe medial and lateral rotation
Medial rotation: Turning a limb inwardly towards the midline.
Lateral rotation: Turning a limb outwardly away from the midline.
Describe circumduction
Circumduction: Can occur at a ball and socket joint, rotation of the ball circularly in the socket.
Describe pronation and supination
Pronation: An inward twist of the limb.
Supination: An outward twist of the limb.
Describe eversion and inversion
Eversion: Rocking of foot outwards
Inversion: Rocking of foot inwards
Describe plantarflexion and dorsiflexion
Dorsiflexion: flexed foot
Plantaflexion: pointed foot
What muscles permit flexion of the shoulder (3)?
Pectoralis major, coracobrachialis and the deltoid.
Where do shoulder flexors insert?
Humeral shaft proximally
What muscles permit extension of the shoulder (3)?
Triceps brachii, deltoid and latissimus dorsi.
Where do shoulder extensors insert?
Humerus
What abducts the shoulder the first 10-15 degrees?
Supraspinatus
After 10-15 degrees what is the main shoulder abductor?
Deltoid
Where do arm abductors insert into?
Lateral humerus
What are adductors of the arm (4)?
Teres major, triceps brachii, pectoralis major and latissimus dorsi.
What is the major medial rotator at the shoulder?
Subscapularis
What are the lateral rotators of the shoulder?
Teres minor and infraspinatus
Where do the rotator cuff all insert?
Infraspinatus, supraspinatus and teres minor all insert into the greater tuberosity of the humeral head, but the subscapularis inserts into the lesser tuberosity.
How many proximal heads and distal ends does the biceps brachii have?
Two proximal heads, and a distal end.
Where does the distal end of the biceps brachii insert into?
Radial tuberosity
Where are the proximal insertions of the biceps brachii?
Short head from Coracoid process
Long head supraglenoid tubercle (labrum) then passes through the intertubercular groove
How does the biceps brachii stabilise the shoulder joint?
The proximal end tendon is continuous with the glenoid labrum, reducing the risk of anterior dislocation, stabilising the joint.
What muscles provide flexion at the elbow?
Biceps brachii, brachialis and coracobrachialis.
What forearm muscle can provide flexion at elbow?
Brachioradialis
What forearm muscles flex the wrist ?
Flexor carpi ulnaris
Flexor carpi radialis
Flexor digitorum profundus Flexor digitorum superficialis.
Palmaris longus
Where do elbow flexors insert and pass?
Pass anterior to joint and insert into proximal radius and ulna
Where do elbow extensors insert and pass?
Pass posterior to joint and insert into proximal radius and ulna
What are some elbow extensors?
Triceps brachii
Aconeus (lower arm)
What are some wrist extensors?
Extensor carpi radialis longus
Extensor carpi radialis brevis
Extensor carpi ulnaris
What are some forearm pronators?
Pronator teres
Pronator quadratus
What are some forearm supinators?
Biceps brachii
Supinator
What are the compartments of the forearm?
Superficial anterior compartment
Intermediate anterior compartment
Deep anterior compartment
Superficial posterior compartment
Deep posterior compartment
What are some hip flexors (4)?
Psoas major, iliacus, pectineus and rectus femoris.
Where do hip flexors insert?
Proximal femur
What are some hip extensors?
Gluteus maximus, and hamstring muscles ( biceps femoris, semitendinosus and semimembranosus)
What are the hamstring muscles?
Biceps femoris, semitendinosus and semimembranosus
What are the quadriceps muscles?
Rectus femoris, vastus medius, vastus intermedius and vastus lateralis
Where do hip extensors insert?
Femur, tibia or fibula
What are some hip abductors?
Gluteus medius, gluteus minimus
Where do hip abductors insert?
Greater trochanter
What are some hip adductors?
Adductor magnus, adductor brevis, adductor longus and gracilis.
Where do hip adductors insert?
Linear aspera
What is a medial rotator of the hip?
Adductor longus
What is a lateral rotator of the hip?
Gluteus maximus
What are flexors of the knee?
Hamstrings in posterior compartment (biceps femoris, semimembranosus, semitendinosus)
Where do the hamstrings insert?
Biceps femoris inserts onto the fibula and semitendinosus and semimembranosus insert onto the tibia.
What are extensors of the knee?
Anterior compartment of the thigh, quadriceps. Rectus femoris, vastus medius, vastus intermedius and vastus lateralis.
Where do quadriceps insert?
Quadriceps tendon above the patella.
What dorsiflexes the ankle
Anterior compartment.
What plantarflexes the ankle
Deep and superficial posterior compartment. Gastrocnemius, soleus, plantaris.
What inverts the ankle?
Posterior compartment. Tibialis posterior, and anterior.
What everts the ankle?
Lateral compartment, fibularis and extensor digitorum longus
What plexus innervates the upper limb?
Brachial plexus
What are the roots of the brachial plexus?
Roots are formed by the ventral (anterior) rami of the C5 to T1 spinal nerves.
How many cervical nerves are there?
8
Describe the organisation of the brachial plexus
Roots Trunks Divisions Cords Nerve branches
What do the roots divide into?
Three trunks, superior, middle and inferior
What do the trunks divide into?
Anterior and posterior division
What do the divisions feed into?
Lateral posterior and medial cords
What are the 5 key nerve branches?
Musculocutaneous Axillary Median Ulnar Radial
What are the roots of the musculocutaneous nerve?
C5-C7
What are the roots of the axillary nerve?
C5-C6
What are the roots of the median nerve?
C5/6-T1
What are the roots of the ulnar nerve?
C8-T1
What are the roots of the radial nerve?
C5-T1
What are the nerves from the posterior cord?
Axillary and radial
What nerve comes from the medial cord?
Ulnar
What nerve comes from the lateral cord?
Musculocutaneous
What nerve comes from both lateral and medial cords?
Median nerve
What roots innervate the BBC muscles?
C5-C6
What muscles does the musculataneous nerve innervate?
Anterior compartment of arm
Biceps brachii, brachialis, coracobrachialis
Where is the dermatome of the musculocutaneous nerve?
Skin of lateral forearm