By Dr MB Samarawickrama (MBBS MS) 31 th Batch July 2008 Muscles and Tendons.

74
By Dr MB Samarawickrama (MBBS MS) 31 th Batch July 2008 Muscles and Tendons

Transcript of By Dr MB Samarawickrama (MBBS MS) 31 th Batch July 2008 Muscles and Tendons.

Page 1: By Dr MB Samarawickrama (MBBS MS) 31 th Batch July 2008 Muscles and Tendons.

By

Dr MB Samarawickrama(MBBS MS)

31th Batch July 2008

Muscles and Tendons

Page 2: By Dr MB Samarawickrama (MBBS MS) 31 th Batch July 2008 Muscles and Tendons.

Muscles

Three types

• Skeletal Muscles

• Cardiac Muscles

• Smooth Muscles

Page 3: By Dr MB Samarawickrama (MBBS MS) 31 th Batch July 2008 Muscles and Tendons.

MusclesNeed to know

• Histology

• Gross Anatomy

• Physiology

Page 4: By Dr MB Samarawickrama (MBBS MS) 31 th Batch July 2008 Muscles and Tendons.

Muscles

Skeletal Muscles

• Formed by number of muscle fibers

• Non branching

Page 5: By Dr MB Samarawickrama (MBBS MS) 31 th Batch July 2008 Muscles and Tendons.

Muscles-Histology

• Skeletal muscles

• Consist of unbranched fibres

• Banded by striations

• Small nuclei, placed peripherally on the surface of the fibres

Page 6: By Dr MB Samarawickrama (MBBS MS) 31 th Batch July 2008 Muscles and Tendons.

Microscopic structure

Page 7: By Dr MB Samarawickrama (MBBS MS) 31 th Batch July 2008 Muscles and Tendons.

• Fiber’s size varies within a single muscle

• Hypertrophy of muscle results increase in size of the fiber

• The number remains the same

Page 8: By Dr MB Samarawickrama (MBBS MS) 31 th Batch July 2008 Muscles and Tendons.
Page 9: By Dr MB Samarawickrama (MBBS MS) 31 th Batch July 2008 Muscles and Tendons.

• These fibres are bound together by a loose areola tissue

• This envelope is known as epimysium

Page 10: By Dr MB Samarawickrama (MBBS MS) 31 th Batch July 2008 Muscles and Tendons.

Muscles-Histology

ENDOMYCIUM,

PERIMYCIUM

EPIMYCIUM

Page 11: By Dr MB Samarawickrama (MBBS MS) 31 th Batch July 2008 Muscles and Tendons.

Cardiac muscle

• Also striated

• Fibres are branched

• Large nuclei placed centrally

Page 12: By Dr MB Samarawickrama (MBBS MS) 31 th Batch July 2008 Muscles and Tendons.
Page 13: By Dr MB Samarawickrama (MBBS MS) 31 th Batch July 2008 Muscles and Tendons.

Smooth muscle• Long spindle shaped cells

• Nucleus lies centrally

Page 14: By Dr MB Samarawickrama (MBBS MS) 31 th Batch July 2008 Muscles and Tendons.

• Parallel cells joined to form muscle fibres

• The fibres arrange Circularly, longitudinally or whorls & spirals with no demonstrable layers

Page 15: By Dr MB Samarawickrama (MBBS MS) 31 th Batch July 2008 Muscles and Tendons.

The form of muscles

Fibres in a muscle arrange in two ways

• Parallel to the line of pull– increase range

of mobility

Page 16: By Dr MB Samarawickrama (MBBS MS) 31 th Batch July 2008 Muscles and Tendons.

The form of muscles

• Oblique to the line of pull – range of mobility

is less– Force of pull is

maximum

Page 17: By Dr MB Samarawickrama (MBBS MS) 31 th Batch July 2008 Muscles and Tendons.

The form of musclesE.g.

muscles with Parallel fibers

• Sartorius

• Rectus abdominis

• Infrahyoid muscles

• Anterior & posterior fibres of the deltoid

Page 18: By Dr MB Samarawickrama (MBBS MS) 31 th Batch July 2008 Muscles and Tendons.

Muscles with Parallel

Fusiform

Page 19: By Dr MB Samarawickrama (MBBS MS) 31 th Batch July 2008 Muscles and Tendons.

The form of muscles

The muscles with oblique fibres

• One of 4 patterns– Unipinate muscles– Bipennate Muscles– Multipinate Muscles-two types

Page 20: By Dr MB Samarawickrama (MBBS MS) 31 th Batch July 2008 Muscles and Tendons.

The form of muscles

Unipinate muscle

• The tendon forms along one margin of the muscle

• All the fibres slope into one side of the tendon

• e.g. Flexor Policis Longus

Page 21: By Dr MB Samarawickrama (MBBS MS) 31 th Batch July 2008 Muscles and Tendons.

The form of musclesBipennate Muscles• The tendon forms centrally

• muscle fibres slope into the two sides of the central tendon.– Like a feather

• e.g. Rectus Fumoris

Page 22: By Dr MB Samarawickrama (MBBS MS) 31 th Batch July 2008 Muscles and Tendons.

The form of muscles

Page 23: By Dr MB Samarawickrama (MBBS MS) 31 th Batch July 2008 Muscles and Tendons.

The form of muscles

Multipinate Muscles

• Two varieties

• Series of bipinnate masses lying side by side

• e.g.• Central part of the deltoid• Subscapularies

Page 24: By Dr MB Samarawickrama (MBBS MS) 31 th Batch July 2008 Muscles and Tendons.

The form of muscles

Multipennate Muscles • cylindrical muscle within

which a central tendon forms

• Into the central tendon muscle fibres converge from all sides

• e.g. Tibialis anterior

Page 25: By Dr MB Samarawickrama (MBBS MS) 31 th Batch July 2008 Muscles and Tendons.

Surface appearance of muscles

• Some more fleshy

• Some largely apponeurotic

• Some have a mixture of two

Page 26: By Dr MB Samarawickrama (MBBS MS) 31 th Batch July 2008 Muscles and Tendons.

Surface appearance of muscles

• That reflect the function of the muscle

• If the muscle bears lot of pressure from adjacent structures – it is covered by an apponeurosis

• Where there is no pressure it is usually flesh

Page 27: By Dr MB Samarawickrama (MBBS MS) 31 th Batch July 2008 Muscles and Tendons.

Origin and insertion of muscle

• No reality in these terms

• Origin – fixed end

• Insertion – moving end

Page 28: By Dr MB Samarawickrama (MBBS MS) 31 th Batch July 2008 Muscles and Tendons.

Origin and insertion of muscle

• But vary depending on the circumstances

• Use the word attachment instead

Page 29: By Dr MB Samarawickrama (MBBS MS) 31 th Batch July 2008 Muscles and Tendons.

Bone markings

• Fleshy origins leaves no marks on bones

• The area is flatten or depressed on the bone

Page 30: By Dr MB Samarawickrama (MBBS MS) 31 th Batch July 2008 Muscles and Tendons.

•e.g. Pec. Major on the clavicle

Page 31: By Dr MB Samarawickrama (MBBS MS) 31 th Batch July 2008 Muscles and Tendons.

Bone markings

• Insertion of a pure tendon almost always leave a smooth mark on the bone

• e.g. Ligamentum patelle attachment

Page 32: By Dr MB Samarawickrama (MBBS MS) 31 th Batch July 2008 Muscles and Tendons.

Bone markings

• Rough marks are made where there is admixture of flesh & tendon

• or where there is a lenthy insertion of aponeurosis

• e.g. Linear aspera femur

Page 33: By Dr MB Samarawickrama (MBBS MS) 31 th Batch July 2008 Muscles and Tendons.
Page 34: By Dr MB Samarawickrama (MBBS MS) 31 th Batch July 2008 Muscles and Tendons.

Bone markingsFlat muscles arise from-flat bone• Muscle origin does not extend to the edge of the flat

bone• It origin from an edge of a curved line

• Between the origin and the edge of the bone is a bare area

• This area is occupied by a bursa

• Which may or may not be communicated with the adjacent joint

• e.g. subscapularis

Page 35: By Dr MB Samarawickrama (MBBS MS) 31 th Batch July 2008 Muscles and Tendons.

Actions of muscles

• The action of muscles or muscle groups are often oversimplified

• Terms denoting action, in particular, emphasize only one of a number of habitual actions

• A given muscle may play different roles in different movements

Page 36: By Dr MB Samarawickrama (MBBS MS) 31 th Batch July 2008 Muscles and Tendons.

Actions of muscles

• these roles may change if the movements are assisted or opposed by gravity

• Single muscle rarely contract alone

• The action is influence by its companions in contraction

Page 37: By Dr MB Samarawickrama (MBBS MS) 31 th Batch July 2008 Muscles and Tendons.

Actions of muscles

• When a muscle crosses two joints

• It mainly act on distal joint to move it

• On proximal joint it act to steady the joint– e.g. Biceps long tendon– Triceps

Page 38: By Dr MB Samarawickrama (MBBS MS) 31 th Batch July 2008 Muscles and Tendons.

Actions of muscles

• In such cases

• Position of the proximal joint changes the length of the muscles

• Thus affect the movement of the distal joint

Page 39: By Dr MB Samarawickrama (MBBS MS) 31 th Batch July 2008 Muscles and Tendons.

Actions of muscles

• e.g. Action of long flexor tendons of the IPJ is affected by the position of the wrist

• Position of the knee affect the action of the Gastrocnemius on the ankle joint

Page 40: By Dr MB Samarawickrama (MBBS MS) 31 th Batch July 2008 Muscles and Tendons.

Actions of musclesSynergic actions• Muscles acting as a prime movers on a certain

joint have a different action when a more distal segment of the limb is in motion.

• Then they act synergistically to stabilized the joint during the movement of the distal joint.

• e.g. short muscles of the shoulder estabilized the shoulder when – wrist fingers & elbow in movement

Page 41: By Dr MB Samarawickrama (MBBS MS) 31 th Batch July 2008 Muscles and Tendons.

Actions of muscles

• Muscles act synergistically in another way

• This is to cancel out unwanted secondary effect.

• e.g. Tricep contract when the forearm is supinated while the elbow is flexed.

Page 42: By Dr MB Samarawickrama (MBBS MS) 31 th Batch July 2008 Muscles and Tendons.

Actions of muscles

• This prevent the flexion of the elbow by the contraction of the biceps

• This will not oppose the supination action.

Page 43: By Dr MB Samarawickrama (MBBS MS) 31 th Batch July 2008 Muscles and Tendons.

Assessment of Muscle Action• Common sense

• Feeling of contraction

• Pullin tendons in dead

• Nerve stimulation of motor nerve

• Electromyography

• Comparative anatomy

Page 44: By Dr MB Samarawickrama (MBBS MS) 31 th Batch July 2008 Muscles and Tendons.

Action of Paradox

• Multiplicity of common movements are aided by gravity

• In such movements opposing muscles contract to keep the limb against the force of gravity

Page 45: By Dr MB Samarawickrama (MBBS MS) 31 th Batch July 2008 Muscles and Tendons.

Action of Paradox

• e.g. When the arm adduct from abducted position

• Deltoid muscle contract which is a muscle of abduction

• This is known as action of paradox

Page 46: By Dr MB Samarawickrama (MBBS MS) 31 th Batch July 2008 Muscles and Tendons.

Blood supply

• Muscles have a rich blood supply

• Arteries and veins pierce the surface in company with the motor nerve

• From muscle belly artery supply the tendon

• Lymphatics run back with arteries

Page 47: By Dr MB Samarawickrama (MBBS MS) 31 th Batch July 2008 Muscles and Tendons.

• Large blood vessels enter the perimysium

• Branches of perimysial blod vesels ramify

• pass inbetween and surrounds the muscle fibers

Page 48: By Dr MB Samarawickrama (MBBS MS) 31 th Batch July 2008 Muscles and Tendons.

Nerve supply of muscles

• Flat muscles of the body wall are pierced by cutaneous nerve

• They do not supply the muscles

Page 49: By Dr MB Samarawickrama (MBBS MS) 31 th Batch July 2008 Muscles and Tendons.

Nerve supply of muscles

In limbs• If a nerve pierces a muscle that nerve supplies

the muscle

• The motor branch leaves proximal to the muscle

• In limbs nerves passes between muscle planes

• This planes distinct morphological masses that have fused together

Page 50: By Dr MB Samarawickrama (MBBS MS) 31 th Batch July 2008 Muscles and Tendons.

Nerve supply of muscles

In limbs

• All the muscles are not supplied by plexus

• Flexor muscles are supplied by anterior divisions

• Extensor muscles are supplied by posterior divisions

Page 51: By Dr MB Samarawickrama (MBBS MS) 31 th Batch July 2008 Muscles and Tendons.

Nerve supply of muscles

• Sensory supply

• In a nerve supply to a muscle contain 40% of sensory nerve fiber

Page 52: By Dr MB Samarawickrama (MBBS MS) 31 th Batch July 2008 Muscles and Tendons.

Nerve supply of muscles

• Certain cranial nerves are purely motor (iii, iv, vi, vii, xii) supply ocular & facial muscles.

• Spinal accessory nerve also contain no sensory fibres

• Sensory supply to those muscles are derived from other adjacent nerves– e.g. trigemial V

Page 53: By Dr MB Samarawickrama (MBBS MS) 31 th Batch July 2008 Muscles and Tendons.

Physiology of muscle

• All skeletal muscle in the body except heart is supplied by somatic nerves– Voluntary muscles

• Heart & all smooth muscles are supplied by autonomic nerves– Involuntary muscles

Page 54: By Dr MB Samarawickrama (MBBS MS) 31 th Batch July 2008 Muscles and Tendons.

Physiology of muscle

• Smooth muscles can elongate to greater extend e.g. bladder

• Skeletal muscle cannot elongate 1/3 of their resting length

Page 55: By Dr MB Samarawickrama (MBBS MS) 31 th Batch July 2008 Muscles and Tendons.

Naming of Muscles• The names given to individual muscles are

usually descriptive, based on

• their shape, size, number of heads or bellies

• Position, depth, attachments, or actions

Page 56: By Dr MB Samarawickrama (MBBS MS) 31 th Batch July 2008 Muscles and Tendons.

Naming of Muscles

The terms used according to the Shape• Deltoid (= triangular)• Quadratus (= square)• Rhomboid (= diamond-shape)• Teres (= round)• Gracilis (= slender)• Rectus (= straight)• Lumbrical (= worm-like)

Page 57: By Dr MB Samarawickrama (MBBS MS) 31 th Batch July 2008 Muscles and Tendons.

Naming of Muscles

The terms used according to the Size

• Major (large)

• Minor (small)

• Longus (= long)

• Brevis (=short)

• Latissimus (= broadest)

• Longissimus (= longest)

Page 58: By Dr MB Samarawickrama (MBBS MS) 31 th Batch July 2008 Muscles and Tendons.

Naming of Muscles

The terms use according to the Number of heads or bellies

• Biceps (= 2 heads)

• Triceps (= 3 heads)

• Quadriceps (= 4 heads)

• Digastric (= 2 bellies)

Page 59: By Dr MB Samarawickrama (MBBS MS) 31 th Batch July 2008 Muscles and Tendons.

Triceps Digastric

Page 60: By Dr MB Samarawickrama (MBBS MS) 31 th Batch July 2008 Muscles and Tendons.

Naming of Muscles

The terms used according to the Position• Interosseus (= between bones)• Supraspinatus (= above spine of scapula)• Infraspinatus (= below spine of scapula)• Dorsi (= of the back)• Abdominis (= of the abdomen)• Pectoralis (= of the chest)• Brachii (= of the arm)• Femoris (= of the thigh)• Oris (= of the mouth)• Anterior , posterior,

Page 61: By Dr MB Samarawickrama (MBBS MS) 31 th Batch July 2008 Muscles and Tendons.

Naming of Muscles

The terms used according to the Depth• Superficialis (= superficial)

• Profundus (=deep)

• Externus (or external)

• Internus (or internal)

Page 62: By Dr MB Samarawickrama (MBBS MS) 31 th Batch July 2008 Muscles and Tendons.

Naming of Muscles

The terms used according to the Attachment

• sternocleidomastoid (from sternum and clavicle to mastoid process)

• coracobrachialis (from the coracoid process to the arm)

Page 63: By Dr MB Samarawickrama (MBBS MS) 31 th Batch July 2008 Muscles and Tendons.

Naming of Muscles

The terms used according to the Action• Extensor , flexor

• Abductor , adductor

• Levator (= lifter), depressor

• Supinator , pronator

• Constrictor , dilator

Page 64: By Dr MB Samarawickrama (MBBS MS) 31 th Batch July 2008 Muscles and Tendons.

Naming of Muscles

These terms are often used in combination:

E.G flexor digitorum longus (= long flexor of the digits)

latissimus dorsi (= broadest muscle of the back).

Page 65: By Dr MB Samarawickrama (MBBS MS) 31 th Batch July 2008 Muscles and Tendons.

Pathology • Hypertrophy

• Atrophy

• Paralysis

• Ischaemia

• Necrosis

Page 66: By Dr MB Samarawickrama (MBBS MS) 31 th Batch July 2008 Muscles and Tendons.

Tendons• Tendons are tissues that connect muscles to

bone, allowing the force of the muscles to move the joints.

• Tendons consist of longitudinally arranged collagen fibres

• Shape cylindrical or flat

• The aponeurosis of the abdominal wall muscles are wide sheats of tendons

Page 67: By Dr MB Samarawickrama (MBBS MS) 31 th Batch July 2008 Muscles and Tendons.

Tendons

• Blood supply is by two main sources

• Descending vessels from the muscles

• Periosteal vessels from the bone of insertion

Page 68: By Dr MB Samarawickrama (MBBS MS) 31 th Batch July 2008 Muscles and Tendons.

Tendons• In long tendons an additional supply present

• From neighboring artery

• If you tear (rupture) or cut (sever) the tendon anywhere along its route unable to move the distal part

• Tendons are stretched tightly as they connect the muscle to the bone. If the tendon tears, the end must be sewn back together again (a surgical repair)

Page 69: By Dr MB Samarawickrama (MBBS MS) 31 th Batch July 2008 Muscles and Tendons.

Tendons

• Synovial sheaths

• Enclose tendons where the range of movement is considerable

• e.g. the tendon in the fingers

• this is to reduce the friction

Page 70: By Dr MB Samarawickrama (MBBS MS) 31 th Batch July 2008 Muscles and Tendons.

Tendons

Page 71: By Dr MB Samarawickrama (MBBS MS) 31 th Batch July 2008 Muscles and Tendons.

Tendons• Sheeth has two layers

– Parietal– Visceral

• Parietal layer firmly attach to the surrounding structures

• Visceral layer firmly fixed to the tendon

Page 72: By Dr MB Samarawickrama (MBBS MS) 31 th Batch July 2008 Muscles and Tendons.

Tendons

• In between

• Thin layer of fluid lubricate the two layers & facilitate movements

• The visceral & parietal layers fused each other on one side

Page 73: By Dr MB Samarawickrama (MBBS MS) 31 th Batch July 2008 Muscles and Tendons.

Tendons

• They do not enclose tendon cylindrically

• Tendon looks pushed into double layers of enclosed sheath

• Blood vessels can enter the tendon between this space

Page 74: By Dr MB Samarawickrama (MBBS MS) 31 th Batch July 2008 Muscles and Tendons.

Tendons