Page 409 - General Knowledge

GENERAL KNOWLEDGE 2019

Veins
 Thin walled blood vessels.
 Carries blood from various parts of the body.
 Have valves in them to prevent back flow.

 Blood flows at low pressure and low speed.
 Carries deoxygenated blood except pulmonary vein.
Capillaries
 Thinnest blood vessels.
 Connect arteries to the veins.
 Helps in exchange of materials like gases, waste products etc.
Blood Cells
Erythrocytes (RBCs)
 RBCs contain haemoglobin and distribute oxygen.
 They are the most abundant cells in blood.
 Non-nucleated, biconcave disc shaped bodies.
 RBC contains about 280 haemoglobin molecules.

Leukocytes (WBCs)
 Part of the body‘s immune system.
 Destroys and removes foreign cells and cellular debris.
 They are much less in number than RBCs (1:600)
 Nucleated, irregularly shaped.
Thrombocytes

 Responsible for blood clotting.
 Changes fibrinogen into fibrin.
 Also known as blood platelets.
 Non-nucleated.
Comparison between plasma and Lymph
Plasma Lymph
Contains 92% of water, 8% blood Contains variety of substances including
plasma proteins. proteins, glucose, salt and WBCs.

Flows within blood vessels. Flows within lymphatic vessels.
Take part in nutrition, excretion, Supplies nutrition to tissue of blood supply.
respiration etc. Takes part in absorption.
Can coagulate because it contains Can coagulate but very slowly.
fibrinogen and prothrombin.

Blood Pressure
 Pressure created by the blood on walls of blood vessels, because of repeated pumping of
heart called blood pressure.

 It is measured by Sphygmomanometer.
 Recorded as systolic/diastolic.
 BP in normal person – 120/80 mmHg.
 Hypertension – Person has persistent high BP.

405 | P a g e shop.ssbcrack.com