The arteries are normally palpable where they run close
to the surface. Figs 5.2 and 6.1 show their basic anatomy.
Arms
Most of the blood supply of the arm is provided by
the axillary artery, which, after giving off some small
branches in the upper arm, becomes the brachial artery.
This divides into the radial and ulnar arteries, which
run down the forearm following their bones. Both
continue to the wrist where they go on to supply the
hands and fingers. The radial artery is very superficial
at the wrist and easily palpable. The veins of the arm
include the digital veins of the hands, the cephalic and
median vein of the forearm and the basilica vein, which
runs the whole length of the arm. In the upper arm
the brachial and cephalic veins run to the shoulder.
These veins drain via the axillary vein into the superior
vena cava.
Legs
The main blood supply to the leg is from the external
iliac artery, which becomes the femoral artery in the
groin. Its main branches are the profunda femoris (deep
femoral) artery in the thigh and the anterior and
posterior tibial arteries in the lower leg. The posterior
tibial artery is usually palpable behind the medial
malleolus and the continuation of the anterior tibial—
the dorsalis pedis is palpable over the dorsum of the
foot. The veins of the leg include the longest vein in
the body: the great saphenous vein. This superficial
vein drains via perforating veins to the deep veins,
which contain valves assisting return of blood to the
heart. Damage to these valves, for example by venous
thromboses, can lead to venous varicosities. The leg
veins drain into the external iliac veins and then into
the inferior vena cava.
Lower limbs
See List 6.1 and Fig. 6.2. Palpate behind the medial
malleolus of the tibia and the distal shaft of the tibia
for oedema by compressing the area for at least 15
seconds with the thumb. This latter area is often tender
in normal people, and gentleness is necessary. Oedema
occurs when fluid leaks from capillaries into the
interstitial space. There are a number of causes. Oedema
may be pitting (the skin is indented and only slowly
refills—Fig. 6.3) or non-pitting. Oedema due to
hypoalbuminaemia often refills more quickly.1
The oedema that occurs in cardiac failure is pitting
unless the condition has been present for a long time
and secondary changes in the lymphatic vessels have
occurred. If oedema is present, note its upper level
(e.g. ‘pitting oedema to mid-calf’ or ‘pitting oedema
to thigh’). Severe oedema can involve the skin of
the abdominal wall and the scrotum as well as the
lower limbs. Oedema secondary to fluid retention
suggests about 6 litres or more is retained. Differential
diagnosis and causes of oedema are listed in Lists 6.2
and 6.3 respectively.
Non-pitting oedema suggests chronic lymphoedema
that is due to lymphatic obstruction (see Fig. 6.4).
Myxoedema that occurs in thyroid disease is due to the
accumulation of hydrophilic molecules in subcutaneous.
tissue.