Lecture Notes 3324 PDF

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Nick Milne's notes - the exam questions/content in 2018 hasn't changed since he taught the unit. These notes are much more detailed than the ones used now...

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ANHB3324 LECTURE NOTES

1 “ONTOGENY RECAPITULATES PHYLOGENY” Ernst Haeckel

HUMAN STRUCTURE AND FUNCTION 3324 THE UPPER LIMB

THIS WEEKS LAB: No lab this week, labs begin Week 2

OUTLINE: Ontogeny and Phylogeny The Pectoral fin The primitive tetrapod forelimb Rotations of the limb in phylogeny Dorsal and ventral muscle/nerve/girdle bone Segmental nerve supply and muscle groups Brachial plexus Muscle groups of the upper limb

READINGS: Any regional anatomy textbook covering the topics listed above.

Ontogeny = The development of the individual Phylogeny = Evolution of the species The development of the individual recapitulates the evolution of the species Classic example is the Development of the frog. Retracing the evolution of vertebrates from fish to reptiles From the tadpole stage (like a fish) 1. 2. 3. 4. 5.

Water breathing creature with tail and no limbs Rudimentary limbs Reduction of tail Breathes air Fully developed limbs,, loss of tail, becomes a land animal.

To the fully developed frog I WANT TO TRACE THE DEVELOPMENT OF THE LIMBS IN VERTEBRATES AND COMPARE IT TO THE GROWTH OF LIMBS IN THE INDIVIDUAL

Nick Milne2015

ANHB3324 LECTURE NOTES EARLY LIMB DEVELOPMENT IN THE FISH (or early human embryo) Slight elevations of ectoderm appear in lateral plate (4th week). Apical ectodermal ridge induces proliferation of limb mesenchyme. Dorsal and ventral muscle masses connect the girdle to the limb bud. Limb girdle in body wall Proximal, middle and distal segments of the limb

2 PRIMITIVE TETRAPOD FORELIMB The characteristic segments of the limb (shoulder, arm, forearm, & hand) Were present in the fins of fossil fish But became fully developed in terrestrial forms (amphibia & reptiles)

The orientation of the limb is still the same: Dorsal is dorsal and Ventral is ventral Pre-axial (thumb side) is front edge of limb

The fin, or paddle has: Preaxial and postaxial borders (front and back edges) Dorsal and ventral surfaces (top and bottom) Dorsal muscles elevate the fin. Attach to dorsal elements of the girdle (“scapula” and vertebrae) Ventral muscles depress the fin. Attach to ventral elements of the girdle (coracoid)

Nick Milne2015

The limbs and mode of locomotion are very similar in fish & reptiles

ANHB3324 LECTURE NOTES MAMMALIAN FORELIMB ROTATIONS 90 degrees LATERAL ROTATION The preaxial border (thumb side) becomes dorsal This brings the dorsal muscles to the posterior aspect of the limb and the ventral muscles to the anterior aspect

3 MAMMALIAN FORELIMB ROTATIONS 90 degrees ADDUCTION Adduction brings the limb under the trunk. (Classic mammalian posture) Preaxial border (thumb side) becomes lateral Dorsal muscles remain on the posterior aspect of the limb

Quadrupedal animals pronate their forearm so that the digits face forwards In humans the limb stays in the same orientation, but we stand on our hindlimbs and the upper limb hangs at our side (90 degrees extension)

Nick Milne2015

ANHB3324 LECTURE NOTES DORSAL AND VENTRAL MUSCLES The limb rotations modify the action of the muscles Primitive dorsal elevators of the fin become extensors of the limb and ventral depressors of the fin become flexors of the limb Dorsal muscles either: Attach to the vertebral column or the true scapula or Lie in dorsal compartments of the limb Ventral muscles either: Attach to the coracoid part of the scapula, clavicle, ribs or sternum or Lie in ventral compartments of the limb

4 Dorsal and Ventral MUSCLE COMPARTMENTS OF THE UPPER LIMB And their Dorsal and Ventral nerves ARM Ventral: Musculocutaneous nerve (C56) Anterior compartment of the arm Dorsal: Radial nerve (C5678T1) Posterior compartment of the arm

FOREARM Ventral: Median nerve C5678T1 Anterior compartment of the forearm Dorsal: Radial nerve (C5678T1) Posterior compartment of the forearm

HAND Ventral: Ulnar nerve (C8T1) Hand

Nick Milne2015

ANHB3324 LECTURE NOTES

5

BRACHIAL PLEXUS TRUE LIMB MUSCLES ATTACH TO LONG BONES OF THE LIMB The brachial plexus supplies all these muscles. This excludes muscles attaching the axial skeleton to the scapula. These muscles are derived from cranial or cervical myotomes Eg. Trapezius and sternomastoid - Accessory nerve CN 11 Serratus anterior, rhomboids, levator scapulae - C3,4,5,6 C5

C6

C7

C8

T1

ROOTS

TRUNKS

DIVISIONS

CORDS

NERVES

Upper

Middle

Anterior and posterior for each trunk

Lateral

Posterior

Musculocutaneous

Axillary

Nick M

Lower

Medial

Median

Radial

BRACHIAL PLEXUS

ANHB3324 LECTURE NOTES

6 EVOLUTION OF THE LOWER LIMB

HUMAN STRUCTURE AND FUNCTION 3324 THE LOWER LIMB

THE PRIMORDIAL HINDLIMB IS A FLAT PADDLE OR FIN. In fish, and in the embryo Dorsal and ventral surfaces - preaxial and postaxial borders

THIS WEEKS LAB: No lab this week, labs begin Week 2

OUTLINE: Ontogeny and Phylogeny The Pelvic fin Dorsal and ventral muscle/nerve/girdle bone Rotations of the limb in phylogeny Segmental nerve supply Upper and lower limb compared

READINGS: Any regional anatomy textbook covering the topics listed above.

Dorsal muscles connect long bones of the limb with the vertebral column or ilium. In fish they elevate the fin. Ventral muscles connect long bones of the limb with the ischium or pubis. In fish they depress the fin.

Nick Milne2015

ANHB3324 LECTURE NOTES

7

EVOLUTION OF THE LOWER LIMB TERRESTRIAL ADAPTATIONS

EVOLUTION OF THE LOWER LIMB MAMMALIAN ADAPTATIONS

The characteristic segments of the limb (pelvis, thigh, leg and foot) Were present in the fins of fossil fish

LIMB CHANGES ORIENTATION 1. Medially rotated so that the preaxial digit (hallux) is medial 2. Adducted to bring the limb under the body 3. Also extended in humans to bring the limb in line with the torso

But became fully developed in terrestrial forms (amphibia & reptiles)

The orientation of the limb is still the same: Dorsal is dorsal and Ventral is ventral Pre-axial (big toe side) is front edge of limb

The limbs and mode of locomotion are very similar in & reptiles

Nick Milne2015

fish Dorsal muscles come to lie on the anterior (cranial) side. Ventral muscles come to lie on the posterior (caudal) side. Pre-axial digit becomes the medial.

ANHB3324 LECTURE NOTES DORSAL AND VENTRAL MUSCLES IN THE LOWER LIMB The limb rotations modify the action of the muscles Primitive dorsal elevators of the fin become anterior extensors, and lateral abductors

8 NERVES OF THE LUMBO SACRAL PLEXUS We have seen dorsal and ventral 1. Aspects of the limb 2. Muscle groups 3. Bones We also have dorsal and ventral nerves

Ventral depressors of the fin Become posterior flexors, and medial adductors of the limb Dorsal muscles either: Attach to the vertebral column or the ilium or Lie in anterior or lateral compartments of the limb Ventral muscles either: Attach to the pubis or ischium or Lie in posterior or medial compartments

Femoral nerve - L2,3,4 Obturator nerve L2,3,4 Lumbosacral trunk L4,5

Superior gluteal nerve - L4,5,S1 Inferior gluteal nerve - L5,S1,2 Sciatic nerve a) Tibial nerve - L4,5,S1,2,3 b) Common peroneal nerve - L4,5,S1,2,3

Nick Milne2015

ANHB3324 LECTURE NOTES Dorsal and Ventral MUSCLE COMPARTMENTS OF THE LOWER LIMB And their Dorsal and Ventral nerves

9 ANTERIOR AND MEDIAL COMPARTMENTS OF THE THIGH Anterior aspect of the hip ANTERIOR COMPARTMENT MUSCLES

Dorsal: Femoral nerve nerve (L234) Anterior compartment of the thigh Dorsal: Gluteal nerves (L45S123) “Lateral” compartment of the thigh Ventral: Obturator nerve (L234) Medial compartment of the thigh Ventral: Tibial nerve (L45S123) Posterior compartment of the thigh

Flexors (and medial rotators) of the thigh and extensors of the knee Hip muscles take origin from: Vertebrae Psoas Ilium Iliacus, sartorius, rectus femoris (and pectineus) Origin from vertebrae and Ilium – there fore dorsal muscles The other three muscles – the vasti – cross the knee only

All supplied by the Femoral nerve Femoral nerve L234 (dorsal)

Ventral: Tibial nerve (L45S123) Posterior compartment of the Leg Dorsal: Deep peroneal nerve (L45S123) Anterior compartment of the leg Dorsal: Superficial peroneal nerve (L45S123) Lateral compartment of the leg

Ventral: Tibial nerve (L45S123) Sole of foot

Nick Milne2015

MEDIAL COMPARTMENT MUSCLES Adductors (and medial rotators) of the hip Take origin from: The Pubis Gracilis, aductor longus, brevis & magnus, and pectineus Origin from Pubis – therefore Ventral muscles All supplied by the Obturator nerve (L234)

ANHB3324 LECTURE NOTES POSTERIOR AND LATERAL COMPARTMENTS OF THE THIGH Posterior aspect of the hip

10 UPPER AND LOWER LIMB COMPARED

POSTERIOR COMPARTMENT MUSCLES

Upper limb is concerned with Manipulation and prehension

Extensors of the thigh and flexors of the knee Take origin from: The Ischium Semitendinosis, semimembranosis, long head of biceps (adductor magnus) Origin fro the Ischium – therefore Ventral muscles

Lower limb is an organ of locomotion

All supplied by the Tibial division of the sciatic nerve (L45S123)

Upper limb is more mobile Upper limb has a whole set of muscles which can move and position the pectoral girdle with respect ot the trunk. Trapezius, rhomboids, levator scapulae, serratus anterior

Lower limb is stronger and more stable The lower limb has its pelvic girdle securely fixed to the vertebral column

The upper limb is an organ of the prehension and manipulation. Therefore an upper limb muscle’s action is usually the same as their function. Most muscles work concentrically The lower limb is an organ of locomotion Therefore a lower limb muscle’s action is not always the same as its function. Most of the time, muscles work eccentrically (resisting and controlling the effects of gravity and momentum) LATERAL COMPARTMENT MUSCLES Adbuctors of the hip (plus other things) Take origin from: The Ilium Gluteus medius and minimus, tensor fascia lata Vertebral column Gluteus maximus Origin from the Ilium – therefore Dorsal muscles Supplied by Superior and inferior gluteal nerves (L45S12) Also the short head of biceps (knee flexor only – not a hamstring) common peroneal nerve (dorsal)

Nick Milne2015

ANHB3324 LECTURE NOTES

11 THE SHOULDER COMPLEX

HUMAN STRUCTURE AND FUNCTION 3324 SHOULDER AND GLENOHUMERAL MOVEMENT

MANY JOINTS INVOLVED Glenohumeral Acromioclavicular

THIS WEEKS LAB: Proximal bones, plexuses and patterns

Sternoclavicular Scapulothoracic

OUTLINE: The shoulder complex

Costovertebral

Scapulo-thoracic Glenohumeral The clavicle Scapular movements and muscles Elevation – Depression Protraction – Retraction Upward and Downward Rotation Glenohumeral movements and muscles Rotator Cuff Muscles Flexion – Extension Adduction – Abduction Medial and Lateral Rotation

Costotransverse Costochondral Sternocostal

Simultaneous movements of all these joints Hard to voluntarily move one joint +ve can compensate for loss of range in one joint -ve one painful joint can upset movements of the whole complex.

Combined movements

Although there are many joints, we only normally refer to movements two joints. Scapulothoracic or scapular movements Glenohumeral

READINGS: Any regional anatomy textbook covering the topics listed above.

We will examine the movements of the two joints separately – but be aware that the movements occur together

Nick Milne2015

ANHB3324 LECTURE NOTES

12 SHOULDER MUSCLES

SCAPULAR MOVEMENTS The scapular slides on the body wall and can move in three directions (and combinations of the those 3) 1. 2. 3.

Elevation – Depression Protraction – Retraction Upward and Downward Rotation

Scapular muscles Levator scapulae Serratus anterior Rhomboids Pectoralis minor Trapezius

In humans and other animals with clavicles the movements of the scapula is regulated by the clavicle. Animals with clavicles and without clavicles: The clavicle is important in the use of the hand for grasping and manipulation. It acts as a strut that, with the muscles as “guy ropes”, forms a secure basis for movements of the arm.

Glenohumeral muscles Supraspinatus Infraspinatus Teres minor Subscapularis Teres major Deltoid Triceps long head Biceps Coracobrachialis

Both Scapular and Glenohumeral (they don’t attach to the scapula) Pectoralis major Latissimus dorsi

Nick Milne2015

ANHB3324 LECTURE NOTES

13 SCAPULAR MOVEMENTS Protraction and Retraction

SCAPULAR MOVEMENTS Elevation and Depression Elevation = Lifting the shoulders As is shrugging (where the scapula moves) Or carrying heavy objects (where the scapula stays still or may even go down!) Muscles involved: Levator scapulae Trapezius (upper fibres) Rhomboids

Depression = lowering the shoulders May be an actual lowering, or merely preventing the scapula going up (as when you support yourself with your arms) Muscles involved: Trapezius (lower fibres) Pectoralis major and minor Latissimus dorsi Gravity

Nick Milne2015

Protraction = shoulders forwards Maybe an actual movement or stopping the shoulder being pushed backwards. Muscles involved: Serratus anterior Pectoralis minor

Retraction = shoulders back May be an actual movement or … Muscles involved Rhomboids Trapezius (middle part) Rhomboids and serratus anterior form a couple that control the mediolateral position of the scapula

ANHB3324 LECTURE NOTES

14

SCAPULAR MOVEMENTS Upward and downward rotation Upward rotation = makes the glenoid cavity face upwards Muscles involved Serratus anterior (lower part) Trapezius (upper and lower parts)

GLENOHUMERAL JOINT The glenohumeral joint is a ball and socket joint. Glenohumeral movements Flexion – Extension Adduction – Abduction Medial and Lateral Rotation Bones The bony socket is very shallow Deepened by the glenoid labrum Secondary socket formed by the acromion, coracoid and coracoacromial ligament: it prevents upward dislocation. The ligaments are very loose to allow free movements, so the joint relies on muscles to maintain its stability The rotator cuff muscles 1. Act as dynamic ligaments to stabilise the joint in all positions. 2. They attach very close to the joint centre and so can not cause strong movements of the arm. 3. They assist other muscles (synergists) Subscapularis Supraspinatus Infraspinatus Teres minor

Downward rotation = makes the glenoid cavity face downwards Muscles involved Pectoralis major Latissimus dorsi Rhomboids Gravity

Nick Milne2015

ANHB3324 LECTURE NOTES GLENOHUMERAL MOVEMENTS Flexion and extension Sagittal plane movement Flexion is the forward movement of the arm. It may be an actual movement or just a stabilising action Muscles involved Pectoralis major (clavicular part) Deltoid (anterior part) Biceps and coracobrachialis

15 GLENOHUMERAL MOVEMENTS Abduction and Adduction Coronal plane movement Abduction is moving the arm away from the body It may be an actual movement or just a stabilising action Muscle Involved Middle part of Deltoid Rotator cuff muscles act as synergists

Extension is the backwards movement of the arm Muscles involved Pectoralis major (sternal part) Deltoid (posterior part) Latissimus dorsi and teres major Triceps (scapular head)

Adduction is bringing the arm to the body Muscles involved Teres major, latissimus dorsi Pectoralis major Anterior and posterior deltoid Gravity

Nick Milne2015

ANHB3324 LECTURE NOTES

16

GLENOHUMERAL MOVEMENTS Medial and lateral rotation Medial rotation is rotation around the long axis of the humerus that moves the anterior part medially. May be the movement itself or a stabilising action like when you carry something between two hands. Muscles involved Teres major and latissimus dorsi Pectoralis major and anterior deltoid Subscapularis

EXAMPLES OF ACTUAL MOVEMENTS It is important to learn the movements and muscles of the scapular and glenohumeral components of the shoulder separately, and not to allow yourself to confuse the two. But, in practice the movements that we do involve both components acting together. For example: Raising the arm laterally to the vertical position 1. 2.

Glenohumeral movement can only perform half of the movement. The scapula must rotate laterally as well.

Pushing forwards with the hand as in opening a heavy door Lateral rotation is rotating the humerus outwards Muscles involved Posterior deltoid Infraspinatus Teres minor

Nick Milne2015

1. 2.

Glenohumeral flexion (and elbow extension), performs most of the action - but. The Scapula must protract as well. This pushes the whole shoulder forwards. a. In people with paralysis of serratus anterior, as they try to push forwards the scapula moves backwards.

ANHB3324 LECTURE NOTES SCAPULAR MUSCLES AND MOVEMENTS Elevate Depress

17

Protract

Retract

Upward rotate

Down rotate

Levator scapulae Serratus anterior Rhomboids Pectoralis minor Trapezius Pectoralis major Latissimus dorsi

GLENOHUMERAL MUSCLES AND MOVEMENTS Flex Supraspinatus Infraspinatus Teres minor Subscapularis Teres major Deltoid Triceps (long) Biceps Coracobrachialis Pectoralis major Latissimus dorsi

Nick Milne2015

Extend

Abduct

Adduct

Medial rotate

Lateral rotate

ANHB3324 LECTURE NOTES

18 THE HIP JOINT - OSTEOLOGY

HUMAN STRUCTURE AND FUNCTION 3324 HIP JOINT, POSTURE AND THE LUMBAR SPINE

The acetabulum (pubis, ilium and ischium) Deep socket – deepened further by the acetabular labrum

THIS WEEKS LAB: Proximal bones, plexuses and patterns

OUTLINE: The hip joint Bones Ligaments Posture and the line of gravity Normal posture Slouched and military posture One legged stances

Acetabulum faces laterally, (inclined anteriorly and inferiorly) Head of femur is 2/3 of a sphere Neck of the femur is directed superomedially, inclines anteriorly Makes an angle of 125 degrees with the femur (males>females)

Introduction to walking

READINGS: Any regional anatomy textbook covering the topics listed above.

The anterior part of the femoral head is outside the acetabulum, covered by the joint capsule and the tendon of Iliopsoas

Nick Milne2015

ANHB3324 LECTURE NOTES

19 THE HIP JOINT Muscles and movements

THE HIP JOINT - LIGAMENTS Ligament of the head is of no mechanical significance, It carries a blood vessel import during development. Capsular ligaments – Iliofemoral, ischiofemoral, pubofemoral. Attach to the Acetabular margins of the hipbone To the 1. Intertrochanteric line of the femur (anteriorly) 2. Femoral neck (posteriorly). Ligamentous fibres spiral around the joint (lower limb medial rotation)

Ball and socket joint, therefore 3 degrees of freedom 1. ...