Ch 20 Peripheral Vascular and Lymphatic System

The heart pumps freshly oxygenated blood through the arteries to all body tissues. Artery walls are strong, tough, and tense to withstand pressure demands; contain elastic fibers, which allow their walls to stretch with systole and recoil with diastole. Veins are parallel that of arteries, but the body has more veins, and lie closer to the skin. Most veins carry deoxygenated blood from the tissues back to the heart; exceptions are the pulmonary and umbilical veins, both of which carry oxygenated blood to the heart. Arteries are more muscular than veins; veins are often closer to the skin and contain valves to help keep blood flowing toward the heart, while arteries carry blood away from the heart.

Temporal artery, carotid artery, brachial artery, femoral artery, popliteal artery, dorsalis pedis, posterior tibial

1. The contracting skeletal muscles that milk the blood proximally, back toward the heart 2. The pressure gradient caused by breathing, in which inspiration makes the thoracic pressure decrease and the abdominal pressure increase 3. The intraluminal valves, which ensure unidirectional flow

Veins have a larger diameter and are more distensible; they can expand and hold more blood when blood volume increases. This is a compensatory mechanism to reduce stress on the heart; this ability to stretch, veins are called capacitance vessels.

Elderly, diabetes, obesity, peripheral vascular disease, pregnancy, smoking, varicose veins, inactivity

Retrieves excess fluid from the tissue spaces and returns it to the bloodstream. During circulation of the blood, somewhat more fluid leaves the capillaries than the veins can absorb. Without lymphatic drainage, fluid would build up in the interstitial spaces and produce edema.

Nodes filter the fluid before it is returned to the bloodstream and filter out the micro-organisms that could be harmful to the body.

- Spleen; (1) to destroy old red blood cells (2) to produce antibodies (3) to store red blood cells (4) to filter micro-organisms from the blood - Tonsils; respond to local inflammation - Thymus; important in developing the T lymphocytes if the immune in children

- Leg pain or cramps - Skin changes on arms or legs - Swelling in the arms or legs - Lymph node enlargement - Medication

• 0 = absent • 1+ , weak • 2+, normal • 3+, increased, • 4+ full, bounding

Modified Allen test is used to evaluate the adequacy of collateral circulation prior to cannulating the radial artery; (a) firmly occlude both the ulnar and radial arteries of one hand while the person makes a fist several times. This causes the hand to blanch (b) ask the person to open the hand without hyperextending it; then release pressure on the ulnar artery while maintaining pressure on the radial artery. Adequate circulation is suggested by a return to the hands normal colour in approximately 2-5 seconds. You must occlude the both arteries uniformly with 5kg (11lb) of pressure for the test to be accurate.

Malnutrition, pallor and coolness occur with arterial insufficiency. Malnutrition: thin, shiny atrophic skin, thick-ridged nails, loss of hair, ulcers, gangrene

Arterial deficit, ulcers occur on tips of toes, metatarsal heads, and lateral malleoli

• 1+ Mild pitting, slight indentation, no perceptible swelling of the leg • 2+ Moderate pitting, indentation, subsides rapidly • 3+ Deep pitting, indentation remains for a short time, leg looks swollen • 4+ Very deep pitting, indentation lasts a long time, leg is very swollen