Topic 7 - Circulatory System - Blood and Blood Groups/Heart/Cardiac Cycle/Lymphatic System Flashcards

Question

CO2 Chemical Conversion in the blood

Answer 1

CO2 + H2O) ⇌ H2CO3 ⇌ H+ + (HCO3)- CO₂ + water → carbonic acid → breaks into hydrogen ions + bicarbonate ions. As the blood is flowing through the capillaries between the body cells, carbon dioxide diffuses into the plasma due to the dfference in carbon dioxide concentration. Some carbon dioxide dissolves n the plasma, some combines with haemoglobin, but most reacts with water to form carbonic acid H2CO3). Carbonic acid then ionises into hydrogen ions and bicarbonate ions:

Answer 2

CO₂ in plasma and from carbaminohaemoglobin diffuses out. H⁺ + HCO₃⁻ recombine into carbonic acid → CO₂ released and exhaled.

Answer 3

CO₂ diffuses from tissues into plasma. Most becomes HCO₃⁻, some binds to Hb.

Answer 4

**Transport medium:** - Carried in blood plasma. **Nutrients:** - Inorganic ions: Na⁺, Ca²⁺, K⁺, Cl⁻, I⁻. Organic molecules: Glucose, vitamins, amino acids, fatty acids, glycerol. **Metabolic wastes:** - Produced by cells, must be removed. - Examples: Urea, creatinine, uric acid. - Carried in solution in plasma.

Answer 5

Prevent blood loss and infection after vessel damage.

Answer 6

1) Vasoconstriction - Arterial muscles constrict → reduced blood flow and loss. 2) Platelet Plug Formation - Platelets stick to damaged vessel wall. - Attract more platelets → forms plug. - Also releases chemicals causing vasoconstriction. 3) Coagulation (Clotting): - Involves clotting factors in plasma. - Forms fibrin threads → traps RBCs, platelets, plasma. - Forms a clot (or thrombus) → seals wound.

Answer 7

Fibrin network contracts → tightens clot, pulls wound edges together. Releases serum (fluid without clotting proteins). Clot dries into scab to protect from infection.

Answer 8

A molecule on the surface of a cell (like a red blood cell) that can trigger an immune response, and determines blood type.

Answer 9

A protein made by the immune system that binds to a specific antigen to help destroy or neutralize it.

Answer 10

Used to treat: excessive blood loss, anaemia, leukaemia, haemophilia, and other conditions. Involves: transferring blood or blood products into a patient’s bloodstream. Early transfusions (17th century): used animal blood—often fatal.

Answer 11

Red blood cells have antigens (sugar and protein markers) on their surface. These antigens can stimulate the immune system if recognized as foreign. The immune system produces antibodies that bind to unfamiliar antigens. Antigen-antibody binding forms a complex → causes agglutination (clumping). Clumping can block blood vessels and be life-threatening. Matching blood groups is essential to prevent immune reactions during transfusions.

Answer 12

- Blood type is based on the presence or absence of antigen A and/or B on red blood cells - Antigens are markers on red blood cells (sugars based molecules for ABO) - Antibodies are proteins in plasma that attack foreign antigens - People do not make antibodies against their own antigens, only ones they don't have - Blood type is inherited through DNA

Answer 13

Karl Landsteiner (1901): Discovered the ABO blood group system by mixing human blood samples. Later discovered the Rh blood group system (1940). ABO and Rh systems are the most important for safe transfusions.

Answer 14

Group A: - Has antigen A on red blood cells - Has anti-B antibodies in plasma Group B: - Has antigen B on red blood cells - Has anti-A antibodies in plasma Group AB: - Has both antigens A and B - Has no antibodies (universal receiver) Group O: - Has no antigens - Has both anti-A and anti-B antibodies (universal donor)

Answer 15

- **Group A** can donate to **A and AB**; can receive from **A and O** - **Group B** can donate to **B and AB**; can receive from **A and O** - **Group AB** can donate to **AB Only**; can receive from **All Groups** - **Group O** can donate to **All Groups**; can receive from **O Only**

Answer 16

- Also called the Rhesus Blood Group System, named after experiments using rhesus monkey blood - Like the ABO system, it is based on antigens on the surface of red blood cells. - Rh antigens are protein based molecules (Not sugar based like ABO antigens)

Answer 17

- **Rh Positive:** The person has Rh antigens on their red blood cells. Does not produce anti-Rh antibodies - **Rh Negative**: The person does not have Rh antigens. May produce anti-Rh antibodies if exposed to Rh antigens (e.g. through transfusion or pregnancy) **Who can donate to whom?** - Rh⁻ can donate to Rh⁻ and Rh⁺ ✅ Safe because there's no Rh antigen to trigger a reaction. - Rh⁺ can only donate to Rh⁺ ❌ Unsafe for Rh⁻ recipients — they may produce anti-Rh antibodies.

Answer 18

- A transfusion transfers blood or blood components from one person to another - Most transfusions require the donor and recipient blood groups to match - There are exceptions: some blood products, like clotting factors may not need matching - Used for severe blood loss, clotting issues, immune support, etc. - Different types are used depending on the patient's needs.

Answer 19

Proteins that are primarily produced in the liver that are crucial for blood coagulation

Answer 20

Blood coagulation is the process of forming a blood clot to stop bleeding. It involves platelets sticking to the injury site and clotting factors triggering a reaction that forms fibrin, which stabilises the clot.

Answer 21

Fibrin is an insoluble protein formed from fibrinogen (a clotting factor) during blood clotting. It creates a mesh that traps blood cells, helping to form a stable clot and seal the wound.

Answer 22

- If blood types are incompatible, red blood cells can agglutinate (clump together). - This occurs when the recipient's antibodies react with the donor's antigens - Clumping can cause red blood cells to disintegrate, which is very dangerous. - To avoid this, ABO and Rh groups must be matched before transfusion

Answer 23

**Who can donate to whom?** - Rh⁻ can donate to Rh⁻ and Rh⁺ ✅ Safe because there's no Rh antigen to trigger a reaction. - Rh⁺ can only donate to Rh⁺ ❌ Unsafe for Rh⁻ recipients — they may produce anti-Rh antibodies. - Anti-Rh antibodies are not normally present in Rh Negative people. - However, if an Rh Negative person receives Rh Positive blood, they may: * Not react at first (as antibodies are made slowly) * Then they may become sensitised - future exposure causes fast, strong reactions * This results in rapid clumping, similar to ABO incompatibility

Answer 24

- Whole Blood - Red Cell Concentrates - Plasma - Platelet Concentrates - Cryoprecipitate - Immunoglobulins - Autologous Transfusion

Answer 25

- Blood with anticoagulant (a substance that prevents blood from clotting), as taken from donor - Used in emergencies/severe blood loss

Answer 26

- Most common transfusion - Made by centrifuging blood to separate red blood cells - May have WBCs and platelets removed - Used for anaemia and heart disease

Answer 27

- Liquid part of blood - Given to patients needed clotting factors (e.g. liver disease of severe bleeding)

Answer 28

- Used when platelets are low or abnormal - Helps blood clotting in bleeding patients

Answer 29

- Made by freezing and thawing plasma - Rich in clotting proteins

Answer 30

- Antibody Proteins from donor plasma - Used for immune deficiency or disease exposure

Answer 31

- Uses the patient's own blood, stored before surgery - Eliminates risk of infection or immune reaction.

Answer 32

- In Australia, blood donation is free and collected by the Red Cross Blood Transfusion Service. - Payment for donations or blood products is prohibited by law in most states. - The Red Cross often faces blood shortages, especially of certain types. - Eligible donors: Healthy individuals aged 16–70 years (parental permission may be needed for 16–17-year-olds in some states). - Benefits: Blood donation is a free, valuable way to help others, offering personal satisfaction to the donor.

Answer 33

- The heart is a muscular pump that moves blood through the body. - Located in the mediastinum, between the lungs, slightly left of the sternum. - Enclosed in the pericardium (membrane that protects and allows movement). - Made of cardiac muscle, which contracts rhythmically.

Answer 34

**The Heart has 4 chambers:** - **Right Atrium** > receives blood from the body - **Right Ventricle** > pumps blood to the lungs - **Left Atrium** > receives blood from the lungs - **Left Ventricle** > pumps blood to the body **Atria:** The top chamber that collects blood **Ventricles:** Bottom chambers that pump blood **Septum:** Separates left and right sides of the heart. - The left ventricle wall is thicker than the right -ventricle wall, as it needs to be much stronger to pump blood through the whole body

Answer 35

- Ensure one-way flow of blood - Prevent backflow during contraction and relaxation of the heart - Valves are located between chambers and arteries. - They stop blood flowing backwards and ensures it moves in the correct direction.

Answer 36

**Atrioventricular (AV) Valves** - between atria and ventricles: - **Tricuspid Valve:** Right atrium --> Right Ventricle (3 flaps) - **Mitrial (bicuspid) valve:** Left atrium --> left ventricle (2 flaps) - Anchored by chordae tendineae (heart strings) to papillary muscles **Semilunar Valves** - at the exit of ventricles: - **Pulmonary valve:** Right ventricle --> Pulmonary Artery (3 Cusps) - **Aortic Valve:** Left ventricle --> Aorta (3 cusps) - Cusps flatten when blood moves forward and seal when blood tries to flow back

Answer 37

"Lub" = AV valves closing "Dub" = Semilunar valves closing

Answer 38

- Blood is pumped by the heart into blood vessels, transporting it to body cells or lungs, and then returning it to the heart. - This movement is called circulation. - The three main types of blood vessels are: Arteries, Capillaries, Veins

Answer 39

- Arteries are blood vessels that carry blood away from the heart to the body or lungs Extra: - They branch into arterioles before reaching capillaries. - Pulmonary artery carries deoyxgenated blood to the lungs

Answer 40

- Thick, muscular walls with elastic fibres - Small lumen (inner space) - No valves - Can stretch and recoil due to elastic tissue

Answer 41

- Transport blood under high pressure - Maintain a continuous blood flow via elastic recoil - Control blood flow by: 1) Vasoconstriction (narrowing to reduce blood flow) 2) Vasodilation (widening to increase blood flow)

Answer 42

**Function:** - Link arteries and veins; form a network to carry blood close to nearly every cell. **Purpose:** - Deliver oxygen and nutrients to cells. - Remove wastes like carbon dioxide. **Structure:** - Microscopic vessels. - Walls are one cell thick, allowing easy diffusion of substances between blood and tissues. Adaptation: Thin walls and extensive networks make them ideal for efficient exchange of materials.

Answer 43

**Function:** - Carry blood towards the heart - Formed by capillaries joining into venules, which then merge into larger veins. **Structure:** - Thin walls, with less smooth muscle than arteries - Not Elastic - Blood flows under low, constant pressure - Often contain valves to prevent backflow of blood and to open/close based on pressure. **Major Veins:** - Superior vena cava: Brings blood from upper body to right atrium. - Inferior vena cava: Brings blood from lower body to right atrium. - Pulmonary veins: Bring oxygenated blood from lungs to left atrium (unlike other veins). ↳ 2 from each lung (4 total).

Answer 44

- Delivers oxygen and nutrients to cells. - Removes carbon dioxide and wastes from cells. - Blood flow must change based on activity level (e.g., rest vs exercise).

Answer 45

Changing heart output: - Heart pumps faster or more forcefully to increase blood delivery. Changing vessel diameter: - Vasodilation: Vessels widen to increase blood flow. - Vasoconstriction: Vessels narrow to reduce blood flow.

Answer 46

The cardiac cycle is one full sequence of events in one heartbeat — involving filling, contraction, and emptying of the atria and ventricles.

Answer 47

Atrial Diastole (Relaxation of Atria) - Here, Atria are relaxed and are filling with blood. - The **Right Atrium** fills with deoxygenated blood from the vena cavae - The **Left Atrium** fills with oxygenated blood from the pulmonary veins AV Valves (tricuspid and bicuspid) are open, allowing blood to start flowing into ventricles passively

Answer 48

Atrial Systole (Contraction of Atria) - The atria contract to push any remaining blood into the ventricles - This tops off the ventricles before they contract - AV valves stay open, semilunar valves are still closed

Answer 49

Ventricular Diastole (Beginning) - Ventricles are relaxed. - Occurs just before they fill up fully - Blood continues trickling in from the atria

Answer 50

Ventricular Systole (Contraction of Ventricles) - Ventricles Contract: **Right Ventricle** pumps blood into the pulmonary artery to the lungs, **Left Ventricle** pumps blood into the aorta to the rest of the body - AV valves close to prevent backflow into atria. - Semilunar Valves (aortic and pulmonary) open due to pressure, allowing blood out

Answer 51

Full Diastole (Heart Relaxation Phase) - Both atria and ventricles relax - Blood flows into the atria again, starting the cycle over. - Semilunar valves close to prevent blood flowing backward from arteries into ventricles.

Answer 52

🔵 Deoxygenated Blood Pathway Body → Vena Cavae (sup./inf.) Right Atrium Right Ventricle Pulmonary Artery (to lungs) Lungs – gas exchange (O₂ in, CO₂ out)

Answer 53

🔴 Oxygenated Blood Pathway Pulmonary Veins (from lungs) Left Atrium Left Ventricle Aorta (to body) Body Tissues – oxygen used up, becomes deoxygenated → returns via vena cavae

Answer 54

- It measures how much blood the heart pumps per minute — critical for delivering enough oxygen to tissues. **Formula:** Cardiac Output (CO) = Stroke Volume × Heart Rate - Stroke Volume (SV): Amount of blood pumped out of one ventricle in one beat (~70 mL in a resting adult). - Heart Rate (HR): Beats per minute (~75 bpm at rest).

Answer 55

- Returns excess fluid from tissues to the circulatory system - Defends the body against pathogens by filtering out foreign particles, antigens, and micro-organisms. - Maintains fluid balance between blood and tissues. 🧪 Fluid collected is called lymph – similar to plasma but lacks red blood cells.

Answer 56

- High pressure in blood capillaries causes some fluid to leak out into tissues. - This fluid becomes interstitial fluid (tissue fluid) - Excess fluid enters lymph capillaries, becoming lymph - Lymph flows through lymph vessels, passes through lymph nodes, and eventually drains into large veins near the heart.

Answer 57

Lymph vessels are thin-walled tubes that collect and transport lymph (a fluid containing white blood cells, proteins, and waste) from tissues back into the bloodstream. - Begin as blind-ended tubes in tissues. - Walls are thin and highly permeable, allowing easy entry of fluid, proteins, and pathogens. - Fluid moves in one direction only (no pump like the heart). - Valves prevent backflow (like in veins). - Flow is aided by: 1) Skeletal muscle contractions 2) Smooth muscle in vessel walls 3) Pressure changes from breathing

Answer 58

**Structure:** - Found along lymph vessels - Contain: Lymphocytes (Produce Antibodies), Macrophages (Perform phagocytosis - engulf pathogens), Reticular Fibers (Create internal meshwork to trap pathogens) **Function:** - Filter lymph before it re-enters blood - Trap and destroy pathogens like bacteria/viruses - Swollen node = immune response (created by lymphocyte production)

Answer 59

Pathogens get trapped in lymph nodes. Macrophages engulf particles (see Fig 5.31). Lymphocytes (B and T cells) are activated. If an infection is present, lymph nodes may: - Become swollen and tender. - Increase lymphocyte production. 🧠 Key idea: Lymph nodes are immune checkpoints that detect and neutralise invaders before they reach the bloodstream.

Topic 7 - Circulatory System - Blood and Blood Groups/Heart/Cardiac Cycle/Lymphatic System Flashcards

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