02. Blood & Lymphatic System

Question 1

What is blood?

Answer 1

Blood is a liquid connective tissue composed of cellular and liquid elements.

Question 2

What are the cellular elements in blood?

Answer 2

Red blood cells
White blood cells
Platelets

Question 3

What is the liquid component of blood?

Answer 3

Plasma

Question 4

What are the 3 functions of blood?

Answer 4

1. Transportation - O2 and CO2, nutrients from gastrointestinal tract, and delivers endocrine hormones.
2. Regulation - pH, body temperature, and osmotic pressure.
3. Protection: Clotting + wound healing, WBC - immune functions.

Question 5

What is normal Blood Volume?

Answer 5

Adult male: 5-6L
Adult female: 4-5L

Question 6

What is the composition of Plasma?

Answer 6

Proteins (7%)
Electrolytes (54%)
Nutrients (38%)
Waste products (8%)

Question 7

Plasma proteins?

Answer 7

Albumin
- Function: maintains osmotic pressure in blood vessels; transports hormones, fatty acids, etc.
- Importance: Fluid balance, transport of insoluble substances

Globulins
- Function: Antibodies (immunoglobulins); transport ions, hormones, lipids.
- Importance: Immune defence, nutrient and molecule transport.

Fibrinogen
- Function: blood clottning, forms fibrin to create clots and stop bleeding.
- Importance: wound healing, scaffolding for tissue repair.

Question 8

What is the structure of RBC?

Answer 8

Shape: Disc-shaped - optimised for efficient gas exchange.
Membrane: Lipid bilayer with proteins - deform for passage through narrow capillaries.
Organelles: No nucleus, mitochondria, ribosomes, maximizing space for hemoglobin.

Question 9

Functions of RBC?

Answer 9

O2 transport - Hemoglobin
CO2 transport - carbaminohemoglobin and bicarbonate ions, regulating blood pH
Buffering capacity: hemoglobin buffers blood pH by binding to H+ (hydrogen ions)

Question 10

Explain Erythropoiesis (New RBC Production)

Answer 10

1. Bone marrow
2. Hematopoietic stem cells (HSCs)
3. Myeloid (RBC, platelets, WBC) or Lymphoid (T cell, B cell, NK cell)

Question 11

RBC Life Cycle

Answer 11

1. Erythropoiesis in bone marrow
2. RBCs in circulation - 120 days
3. Spleen and liver macrophages break down aging RBC to bilrubin, iron and amino acids.
4. Liver processes bilrubin into bile.
5. Small intestine excretes bile in feces.
6. Kidneys excrete urine and release erythropoietin (EPO) to stimulate erythropoiesis.

Question 12

What is Anemia?

Answer 12

Deficiency in RBC production leading to reduced number of mature RBCs in bloodstream.
Can be caused by dietary factors and genetic factors.

Question 13

ABO Blood Group System

Answer 13

A: Anti-B antibodies
B: Anti-A antibodies
AB: No antibodies
O: Both

Question 14

Who can donate to who?

Answer 14

A –> A, AB
B –> B, AB
AB –> AB
O –> All

Question 15

Rhesus Blood Group System

Answer 15

Rhesus factor (RhD) on RBCs. If yes –> positive.

Question 16

Explain the Immune response to tissue damage

Answer 16

1. Macrophages activates –> secrete cytokines (signal protein) –> Blood vessel leakiness increase.
2. Neutrophil moves from blood stream and begin phagocytosis (cells digest particles).
3. Mast cells releases histamine –> further increase blood vessel permeability. Dendritic cells transport pathogen framents to lymph nodes to activate lymphocytes.

Question 17

Explain Platelet activation & Clotting

Answer 17

1. Damaged blood vessels –> triggers release of clotting factors –> platelets activate –> goes to wound.
2. Vasoconstriction –> limits blood flow + platelets form a sticky plug.
3. FIBRIN mesh around the plug –> insoluble clot.

Question 18

Lymfsystemets organ

Answer 18

Mjälten
Brässen (thymus)
Tonsillerna
Lymfkärl
Lymfkörtlar

Question 19

Thrombosis

Answer 19

Formation of blood clot in blood vessel

Question 20

Lymfsystemets funktioner

Answer 20

• Vätska tillbaks till blodet
• Förebygga svullnad
• Bibehålla blodvolym
• Transportera fett från tunntarmen till blodet
• Försvara kroppen mot patogener

Question 21

Lymfan

Answer 21

• Kommer från blodplasman som läcker ut ur minsta kapillärerna
• Dränerar interstitialvätskan (vätskan som finns i vävnaderna)
• Rörs mha muskelkontraktioner och andning.

Question 22

How can RBC regulate blood pH?

Answer 22

Hemoglobin in RBC buffers the blood by binding to hydrogen ions (H+)