Transcript UPPER LIMB - Larry Frolich

UPPER LIMB
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What is a limb?
Skeleton
Joints
Shoulder/Scapula
muscles
Brachial plexus—
getting spinal nerves
out onto limb
Muscles—anterior
and posterior
compartments
Sensory innervation
Surface anatomy
Frolich, Human Anatomy,UpprLimb
From Royal Collection da
Vinci drawings
What is a limb?
• Ventral somatic outgrowth of
outer tube
– Bones (made of bony tissue,
cartilage, and other tissues)
– Joints
– Muscles
– Nerves (with motor neurons to
muscles, sensory neurons to
skin, proprioceptors)
• No viscera--all innervation is
somatic (motor or sensory)
from ventral ramus of spinal
nerve (except autonomics to
blood vessels)
Frolich, Human Anatomy,UpprLimb
Upper Limb Skeleton
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Scapula
Humerus
Radius, ulna
Carpals-proximal, distal
• Digits
– Metacarpals
– Phalanges
Frolich, Human Anatomy,UpprLimb
Joints
JOINT BETWEEN MOVEMENT TYPE
Frolich, Human Anatomy,UpprLimb
Frolich, Human Anatomy,UpprLimb
Muscle origins and insertions
• Muscle crosses joint
• Origin is usually proximal and
insertion is usually distal
• Origin is considered fixed in
analyzing muscle action
• Muscle action (concentric) is
given by movement of
insertion relative to origin
across joint
• Remember:
– Sometimes insertion might be
fixed
– Muscle may be active
isometrically and concentrically
giving different real function
during real activity
Frolich, Human Anatomy,UpprLimb
Muscles of Scapula
• If INSERTION on
scapula, muscle moves
scapula
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Trapezius
Rhomboids
Pectoralis Minor
Serratus Ventralis
Levator Scapulae
• If ORIGIN on scapula,
muscle moves arm
– Teres Major
– Latissimus Dorsi (partially
on scapula)
Frolich, Human Anatomy,UpprLimb
Rotator Cuff
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• Muscles originate on
fossae of scapula
• Help support “open
socket” of shoulder
joint
• Insert around ball of
femur
• Medial and lateral
rotation of upper limb
• Typical baseball
pitcher injury
Frolich, Human Anatomy,UpprLimb
Supraspinatus
Infraspinatus
Teres minor
Subscapularis
Axilla = Armpit
• Region between arm and chest
• Boundaries
– Ventral - pectoral muscles
– Dorsal = latissimus dorsi, teres major
subscapularis
– Medial = serratus ventralis
– Lateral = bicipital groove of humerus
• Contents
– Axillary nerves and blood vessels
– Axillary lymph nodes
– And….the……Brachial plexus
Frolich, Human Anatomy,UpprLimb
Frolich, Human Anatomy,UpprLimb
Brachial Plexus
Frolich, Human Anatomy,UpprLimb
• Posterior Compartment—posterior cord
• Anterior compartment—medial, lateral cords
• Name of cord is relative to axillary artery
Brachial plexus organizes nerves out to
muscles of upper limb
• One posterior nerve
– Radial n.
• Three anterior nerves
– Musculocutaneous n.
– Median n.
– Ulnar n.
Frolich, Human Anatomy,UpprLimb
Muscles and nerves by compartment
ANTERIOR POSTERIOR
NERVES
M-C, ulnar,
median
MOVEMENT Flexion
Radial
MUSCLES
Triceps,
extensors
Extensors from
lateral
epicondyle
TWIST
Frolich, Human Anatomy,UpprLimb
Biceps,
flexors
Flexors from
medial
epicondyle
Extension
POSTERIOR AND ANTERIOR COMPARTMENTS
Frolich, Human Anatomy,UpprLimb
• Biceps—anterior compartment, flexion (M-C n.)
• Triceps—posterior compartment, extension (radial n.)
Frolich, Human Anatomy,UpprLimb
Anterior Compartment Forearm--flexors
Medial Epicondyle
Brachioradialis
Pronator Teres
Flexor Carpi Radialis
Flexor Carpi Ulnaris
Flexor Retinaculum
Anterior
View
Frolich, Human Anatomy,UpprLimb
Flexor Digitorum Superficialis
is deep to other flexors
Posterior Compartment of Forearm--extensors
Lateral Epicondyle
Extensor digitorum
Extensor carpi ulnaris
Posterior View
Frolich, Human Anatomy,UpprLimb
Brachioradialis
Ext Carpi Radialis Longus
ANTERIOR MUSCLES
• M-C nerve
– Biceps
– brachialis
• Median nerve
– Forearm flexors
– Thumb intrinsics (1M$
nerve)
• Ulnar nerve
– Flexor carpi ulnaris
– Hand intrinsics
Frolich, Human Anatomy,UpprLimb
POSTERIOR MUSCLES
• Muscles (radial nerve)
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Triceps
Anconeus
Brachioradialis
Carpal, digit extensors
Sensory from limb
(dermatomes/sensory skin
segments from spine)
• Dermatomes extend
over limbs
• Twisted orientation
reflects twisting of
limb during
development
• Named nerves
generally innervate
skin over muscles
that they innervate
Frolich, Human Anatomy,UpprLimb
Sensory territory of nerves
REMEMBER: Brachial
plexus re-directs spinal
routes into named nerves
covering certain territory
Cutaneous branches of
medial cord/ulnar nerve
Frolich, Human Anatomy,UpprLimb
Routes of nerves (in human)
• M-C: between biceps brachii and brachialis
• Median: medial/posterior to biceps, branches
into forearm flexors at elbow then to hand
through carpal tunnel
– Recurrent median (1M$) superficial at wrist to thumb
over thenar emminence) deficit - ape’s hand
• Ulnar: medial in arm, posterior to medial
epicondle of humerus (funny bone) down medial
forearm medial to carpal tunnel into palm
• Radial: deep posterior arm around lateral
epicondyle of humerus to forearm (deep and
superficial branches)
Frolich, Human Anatomy,UpprLimb
Median Nerve
Ulnar Nerve
Brachial Artery
Musculocutaneous Nerve
UlnarArtery
Where’s Radial Nerve?
Radial Artery
Median Nerve
Frolich, Human Anatomy,UpprLimb
Ulnar Nerve
Surface Anatomy of Upper Limb
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Biceps + Triceps brachii
Olecranon Process
Medial Epicondyle
Cubital Fossa
– Anterior surface elbow
– Contents
• Brachial Artery
• Median Nerve
– Boundaries
• Medial = Pronator teres
• Lateral = Brachioradialis
• Superior = Line between epicondyles
Frolich, Human Anatomy,UpprLimb
Surface Anatomy
of Upper Limb
• Carpal Tunnel
– Carpals concave
anteriorly
– Carpal ligament covers it
– Contains: long tendons,
Median nerve
– Inflammation of tendons =
compression of Median
nerve
• Anatomical Snuffbox
Frolich, Human Anatomy,UpprLimb
– Lateral = E.pollicis brevis
– Medial = E. pollicis longus
– Floor = scaphoid, styloid
of radius
– Contains Radial Artery
(pulse)
Suggestion: a muscle table
organized by
Joint crossed?
Nerve innervating?
Action?
Compartments?
All of the above?
MUSCLE ACTION ORIGIN
INSERTION INNERVATI ON
(cord to nerve)
Biceps
Radial
tuberosity
Flex, sup.
Frolich, Human Anatomy,UpprLimb
Humerus,
glenoid
Medial cord—M-C.
Frolich, Human Anatomy,UpprLimb