Question

Write a Paragraph regarding these topics

G. Pharmacology 3. venipuncture a. venous anatomy b. supplies c. procedural technique

Answer 1

Ans) Pharmacology-

Pharmacology is the branch of biology concerned with the study of drug or medication action, where a drug can be broadly defined as any man-made, natural, or endogenous molecule which exerts a biochemical or physiological effect on the cell, tissue, organ, or organisms.

- Venipuncture: the puncture of a vein as part of a medical procedure, typically to withdraw a blood sample or for an intravenous injection.

- Venous anatomy-

The venous system is that part of the circulation in which the blood is transported from the periphery back to the heart. We distinguish between the superficial and the deep venous systems.

The superficial subcutaneous venous system in the legs includes the long saphenous vein and the short saphenous vein. It transports the blood from the surface (skin and subcutaneous tissues) where it collects in the deep veins.

The deep venous system includes the iliac, femoral, popliteal and deep femoral veins. The deep veins generally run parallel to the corresponding arteries.

These two venous systems are separated from each other by connective tissue fascia and muscles and are connected by a third venous system – the perforating veins (=communicating veins).

The venous wall consists of three layers:

intima (= inner layer)
media (= middle layer) and
adventitia (= outer layer)
The walls of the veins are thinner than those of the arteries. They are more distensible because they contain fewer elastic and muscle fibres.

The veins have crescent-shaped valves at longer intervals in the lumen that divide the long vessels into segments. These valves open as soon as the blood is pressed upwards towards the centre of the body against gravity and close in the instant that the blood comes to a "standstill" and would start to flow backwards.

Venous supplies-

Grossly, the venous system is composed of venules and small and great veins, which serve to return blood from tissues to the heart (see the image below). The systemic venous system brings deoxygenated blood from tissues and organs back to the right atrium of the heart, whereas the pulmonary venous system brings oxygenated blood from the pulmonary circulation back to the left atrium of the heart.

Venipuncture procedural techniques-

- Selection of proper vein in antecubital fossa.

- When a needle from a hub or transfer device is inserted into the stopper, the tube's vacuum automatically pulls in the required volume of blood. The needle is attached to the tube holder by the phlebotomist prior to collection, or may come from the manufacturer as one unit.

- Labelling the sample.