Human Anatomy Vol 1

(mdmrcog) #1
UPPER LIMB

Flexor
digitorum
supedicialis

Flexor
digitorum
profundus

(a) (b)
Figs 10.34a and b: (a) Flexor digitorum superficialis, and (b)
flexor digitorum profundus

Segmenlol lnnervolion of Movements of Upper limb
Figures 10.35a to f shows the segments of the spinal
cord responsible for movements of the various joints
of the upper limb.
The proximal muscles of upper limb are supplied
by proximal nerve roots forming brachial plexus and
distal muscles by the distal or lower nerve roots. In
shoulder, abduction is done by muscles supplied by
C5 spinal segment and adduction by muscles
innervated by C6, C7 spinal segment.
Elbow joint is flexed by C5, C6 and extended by C7,
C8 innervated muscles. Supination is caused by muscle
innervatedby C6 spinal segment evenpronationis done
through C6 spinal segment.
Extension and flexion of wrist is done through C6,
C7 spinal segments. Both the palmar and dorsal
interossei are innervated by Th^1 spinal segment.
The interphalangeal joints also are flexed and
extended by same spinal segments, i.e. C7, CB.

Sternoclavicular joint is a saddle variety of synovial
joint. Its cavity is divided into two parts by an
articular disc.
Movements of shoulder girdle help the movements
of shoulder joint during 90'-180' abduction

(e) (r)
Figs 10.35a to f: Segmental innervation of movements of the
upper limb

C6, C7

a
a

a
a

Shoulder joint is freely mobile and is vulnerable
to dislocation.
Ulnar nerve lies behind medial epicondyle. It is
not a content of the cubital fossa.
Carrying angle separates the wrist from the hip
joint while carrying buckets, etc.
Biceps brachii is an important supinator of forearm
when the elbow is flexed.
Kings pronate, while beggars supinate.
Movements of pronation and supination are not
occurring at the elbow or wrist joints.
First carpometacarpal joint is the most important
joint as it permits the thumb to oppose the palm/
fingers for holding things.
Shoulder joint commonly dislocates inferiorly.
Ulnar nerve lies behind medial epicondyle,
pressing the nerve cause tingling sensation. That
is why the bone is named "humerus".
Giving is pronation, receiving is supination.
Picking up food with digits is pronation, putting
it in the mouth is supination.
Axis of movements of abduction and adduction
of fingers is through the centre of the middle finger'

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Elbow
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