The cardiovascular system- the blood

Question 1

definition of blood

Answer 1

a liquid that fills the vascular compartment and serves to transport dissolved materials and blood cells throughout the body

Question 2

what percentage of the total blood volume is plasma?

Answer 2

55%

Question 3

what percentage of the total blood volume is white blood cels and platelets?

Answer 3

<1%

Question 4

what percentage of the total blood volume is red blood cells?

Answer 4

45%

Question 5

How many litres of blood does an average human body have?

Answer 5

5L

Question 6

what are the main functions of blood?

Answer 6

• Respiration: supply of oxygen to tissue and cells,
  removal of carbon dioxide from tissues and cells
• Transport
  *Nutrients to the tissues and cells
  *Waste products from cells to the kidney and liver
  *Messages such as hormones around the body
• Protection from infection: the immune system
• Repair of tissue damage
• Thermoregulation

Question 7

What are the different constituents of the plasma?

Answer 7

• water
• ions
• plasma proteins
• substances transported by blood (nutrients, waste products of metabolism, respiratory gases, hormones)

Question 8

What are the different types of cells?

Answer 8

• red blood cells
• white blood cells (leukocytes)
• platelets

Question 9

what is the name for the process of formation of blood?

Answer 9

heamatopoesis

Question 10

where does the formation of blood happen?

Answer 10

in bone marrow

Question 11

what are the two types of marrow?

Answer 11

red marrow- in flat bones and produces most blood cells
yellow marrow- in long bones and produces some WBCs

Question 12

what tissue in the bone marrow supports blood cell development?

Answer 12

stroma

Question 13

how are platelets formed?

Answer 13

fragments of megakaryocyte that are broken off

Question 14

what is the site of destruction of blood cells?

Answer 14

the spleen

Question 15

red blood cells

Answer 15

• Biconcave disks
• 7-12μm in diameter
• No nucleus (anucleate)
• No mitochondria
• 4-6 x 1012/L about 25 trillion in the average human with 5L of blood
• Long life span - 120 days (300 miles)

Question 16

function of red blood cells

Answer 16

• Transport of oxygen and carbon dioxide around
  the body
• Critical role in respiration

Question 17

haemoglobin

Answer 17

• Responsible for the red appearance of RBC’s
• About 250 million molecules / RBC
• 4 polypeptide chains each with a cofactor called a haem group, that
  has an iron atom at the centre.
• Each iron atom binds one molecule of O2.
• Co-operativity in O2 binding and release.
• Binds to O2, CO2 and NO (can also bind CO) and transports these molecules around the body

Question 18

How is CO2 transported out of the body?

Answer 18

• CO2 is produced in tissue cells and transported though interstitial fluid into the plasma
• in the plasma, around 9% makes it’s way to the lungs
• the rest diffuses into red blood cells and 23% gets picked up by Hb
• the rest reacts with water to form carbonic acid that splits into bicarbonate and H
• the hydrogen gets transported by the Hb
• the bicarbonate gets transported in the plasma

Question 19

what is anemia?

Answer 19

A reduced haemoglobin concentration in blood
Several classifications
- Low haematocrit
- Small red cells

Question 20

what are the common causes of anemia?

Answer 20

• Poor diet – iron deficiency
• Chronic blood loss
• Malabsorption of iron
• Pregnancy

Question 21

what are the signs and symptoms of anemia?

Answer 21

Fatigue, pallor, tachycardia, shortness of breath

Question 22

what are the different types of leukocytes (white blood cells)?

Answer 22

• lymphocyte
• basophil
• neutrophil
• monocyte
• eosinophil

Question 23

neutrophil

Answer 23

• Multi-lobed nucleus
• Neutral-staining granules

Question 24

what are the functions of neutrophils?

Answer 24

• Vital role in protection from bacterial infections
• Phagocytosis of bacteria

Question 25

eosinophils

Answer 25

- Bi-lobed nucleus - Large pink-staining granules

Question 26

what are the functions of eosinophils?

Answer 26

- Immune-protection - Phagocytosis of antibody-coated pathogens - Attacks parasites - Allergic responses

Question 27

basophils

Answer 27

- Bi-lobed nucleus - Large purple-staining granules

Question 28

what are the functions of basophils?

Answer 28

- Release of histamine during inflammation - Not phagocytes

Question 29

monocytes/macrophages

Answer 29

- Large kidney-shaped nucleus

Question 30

what are the functions of monocytes/ macrophages?

Answer 30

- Vital role in protection from infections - Ingest bacteria, dead cells and cellular debris - Phagocytosis

Question 31

lymphocytes

Answer 31

- Large and relatively round nucleus that fills the cytoplasm - Divided into two types of cell due to function - T & B cells

Question 32

what are the functions of lymphocytes?

Answer 32

- Central role in the immune system – protecting from infections, esp viral infections - Some lymphocytes attack pathogens directly (T-cells) and some produce antibodies (B-cells)

Question 33

natural killer cell

Answer 33

- Look similar to lymphocytes (same family) - Large round nucleus - Purple-staining granules - very rare

Question 34

what are the functions of natural killer cells?

Answer 34

- Immunological surveillance - Kill virus infected cells and some tumour cells non-specifically ie. part of innate immunity

Question 35

platelets

Answer 35

- Small anucleate fragments of large precursor cells called megakaryocytes - Appear in blood films as dark-staining granules

Question 36

what are the steps of haemostasis?

Answer 36

1- injury to blood vessel and collagen is exposed and platlets adhere to hole 2- platlets are activated and aggregate which forms a thrombus 3- you end up with a fibrin clot formation with trapped cells

Question 37

How to remeber different white blood cells:

Answer 37

Never (Neutrophils) Let (Lymphocytes) Monkeys (Monocytes) Eat (Eosinophils) Bananas (Basophils)