Blood

Question 1

What is Blood?

Answer 1

Blood is the only fluid tissue in the human body and is classified as a connective tissue.

Question 2

Name the main components of blood.

Answer 2

Composed of extracellular matrix called plasma and formed cells that are living.

Plasma - 55% of the volume
Cellular components - 45% of the volume
— contains the buffy coat(WBCs + Platelets) and RBCs —-

Question 3

Name the 7 functions of blood

Answer 3

1. transport of gases, nutrients and waste products
   oxygen, glucose and CO2
2. Transport of processed molecules
   eg: Vitamin D
3. Transport of regulatory molecules
   hormones and enzymes
4. Regulation of pH (7.4) and osmosis
   bicarbonate and other ions
5. Maintenance of body temperature
   from interior to exterior (skin)
6. Protection against foreign substances
   Innate (Phagocytes) and adaptive (Antibodies)
7. Clot Formation
   1st stage in tissue repair

Question 4

Define Plasma.

Answer 4

Straw coloured, fluid portion of the blood in which formed elements (blood cells) are suspended in.

Question 5

What’s Serum?

Answer 5

Plasma from which fibrinogen has been separated in the process of clotting

Question 6

Name and list the components of plasma in detail.

Answer 6

water ~90%
Plasma proteins- (including albumin, globulin and fibrinogen) ~ 7-8%

the rest:
electrolytes
Na, K, Ca
Gases
CO2, O2
nutrients
lipids, glucose and amino acids
nitrogenous waste
uric acid and urea
waste products
bilirubin, creatinine
other: hormones(erythropoietin, insulin), vitamins

Question 7

Name and list the cellular components
Name the function of each

Answer 7

Cellular components of blood 45%

Erythrocytes - RBCs = O2 and CO2 transport
Leucocytes - WBCs = Defence against microbial pathogens
thrombocytes - platelets = blood clotting

Question 8

Define Haematocrit

Answer 8

percent of blood cell volume that is RBCs

Question 9

define the term formed elements

Answer 9

A formed element is the basic constituent part of a system

formed elements of blood refers to the non-fluid elements - the cells.

Question 10

What are the 3 formed elements of blood.

Answer 10

RBC - erythrocytes
WBC - leucocytes
Platelets - cell fragments - thrombocytes

Question 11

Name the granular and agranular leucocytes

Answer 11

Granular - Neutrophils, Eosinophils, Basophils
Agranular - Monocytes, lymphocyte

Question 12

Name the Leucocytes in order of greatest to least in volume

whats the most numerous leucocyte

what’s the least numerous?

Answer 12

Neutrophils
eosinophils
basophils

neutrophils

basophils

Question 13

What are the functions of plasma proteins?

Answer 13

Plasma proteins have several functions. They contribute to oncotic pressure, which plays an important role in interstitial fluid reabsorption. Plasma proteins also transport gases, nutrients, hormones, and waste products. They help maintain viscosity, which aids in maintaining arterial pressure. Additionally, plasma proteins act as pH buffers and provide protection against pathogens through the production of antibodies.

Question 14

What are the formed elements in blood?

Answer 14

The formed elements in blood are erythrocytes (red blood cells), leucocytes (white blood cells), and platelets (cell fragments).

Question 15

What is the main function of erythrocytes (red blood cells)?
Describe the structure and appearance and what it contains.
how long do they live? what replaces them?

Answer 15

The main function of erythrocytes is to transport oxygen.
They contain haemoglobin, a molecule that binds to oxygen and facilitates its transport throughout the body.

Erythrocytes are biconcave disks and lack membrane-bound organelles such as mitochondria and a nucleus.

Their lifespan is approximately 120 days, and they are continuously destroyed and replaced in the red bone marrow.

Question 16

How does oxygen transport occur in the blood?

Answer 16

Oxygen transport in the blood is facilitated by haemoglobin. Each haemoglobin molecule can bind reversibly to four oxygen molecules.

This binding of oxygen increases the affinity for oxygen and encourages saturation where oxygen levels are high and encourages dissociation where oxygen levels are low.

Factors such as pH, temperature, and carbon dioxide levels can affect the binding and release of oxygen by haemoglobin.

Question 17

What are the different types of leucocytes (white blood cells)?

Answer 17

The different types of leucocytes are granulocytes and agranulocytes. Granulocytes include neutrophils, eosinophils, and basophils, while agranulocytes include lymphocytes and monocytes.

Question 18

What is the role of platelets in the blood?

Answer 18

Platelets, derived from ruptured multinucleate cells called megakaryocytes, are small, anucleate cell fragments.

They are needed for blood clotting (hemostasis). When a blood vessel is damaged, platelets become sticky and form a clot by adhering to collagen fibres and attracting more platelets.
This process involves a cascade of clotting factors, resulting in the formation of a fibrin network.
Clotting disorders can lead to thrombus (clot in an undamaged blood vessel) or embolus (a thrombus that breaks free and travels through the circulation), as well as bleeding disorders such as thrombocytopenia (platelet deficiency) or haemophilia (missing clotting factors).