Chapter 9 Flashcards
The Heart
What is the circulatory system?
The circulatory system contains blood vessels with a pump and valves ensure one-way blood flow.
- Valves prevent backflow of blood.
What is the circulation of a Fish?
They have single circulation.
Blood passes through the Heart once.
They have 2 chambers. 1 Atrium and 1 Ventricle.
- Only Systemic circulation.
What is the circulation of a mammal?
Mammals have double circulation.
Blood passes through the heart twice to complete 1 circuit.
They have 4 chambers; 2 Atria, 2 Ventricles.
What is the advantage of double circulation?
Double circulation allows O2 and glucose to travel faster and more efficiently through the blood, since double circulation maintains a higher blood pressure than single.
What are the parts of the heart in order?
(Deoxygenated blood) Vena Cava -> Right Atrium -> Tricuspid valve -> Right ventricle -> Semi-lunar valve -> Pulmonary Artery.
(Oxygenated blood) Pulmonary Vein -> Left Atrium -> Bicuspid valve -> Left ventricle -> Semi-lunar valve -> Aorta.
How many valves are present in the Heart?
4 Valves:
- Bicuspid (Left side)
- Tricuspid (Right side)
- 2 Semi-lunar valves.
What are the Coronary arteries?
These arteries supply the Heart with blood.
Which walls are thicker; Atria or Ventricles?
The Ventricles have thicker muscle walls since they pump blood out of the heart, so they need high pressure.
Which ventricle is thicker and why?
The left ventricle has thicker walls, since it has to pump blood at higher pressure to the WHOLE BODY
- While right ventricle only pumps to the lungs.
How can we measure Heart activity?
- ECG
- Pulse rate
- Using stethoscope
What is the effect of physical activity on Heart rate?
The heart rate increases.
- This is because, during exercise muscle cells respire, and need more oxygen and glucose for respiration and waste products like Co2 need to be removed faster.
- This is also for oxygen debt muscles respire anaerobically
What is coronary heart disease?
- This is when the coronary artery becomes blocked with fatty deposits called Plaques.
- There is formation of atheroma, blood clots formed on the rough layers, which narrow the blood vessels, and so the heart has restricted blood flow.
- This leads to Angina (severe chest pain) and then heart attack.
How can we reduce the risk of coronary heart disease?
- Quit smoking
- Maintain a healthy diet with reduced animal fats
- Exercise regularly
What are blood vessels and its types?
Blood vessels are tubes in which blood circulates through the body.
The 3 types are;
Arteries, Veins and Capillaries
What is the structure of Arteries?
Arteries carry blood AWAY from the heart towards organ.
- They carry oxygenated blood EXCEPT for pulmonary artery.
- They have THICK MUSCULAR WALLS and elastic fibres to withstand blood carried at high pressures.
- Blood is carried at HIGH PRESSURE.
- They have a NARROW LUMEN; This maintains high pressure.
- NO VALVES; High B.P prevents backflow.
What is the structure of Veins?
Veins carry blood TOWARDS the heart.
- They carry deoxygenated blood.
(Except for Pulmonary Vein)
- Blood flows slowly in veins
- THIN MUSCULAR WALLS; Blood carried at LOW PRESSURE.
- They have a LARGE LUMEN
- VAVLES PRESENT; Prevent backflow
What is the functions of Capillaries?
Capillaries are the smallest blood vessels, they CONNECT Arteries and Veins.
- Capillaries provide an exchange of Oxygen, Nutrients and waste products between Blood and Body cells.
- They are ONE CELL THICK; substances can diffuse fast.
What is the structure of Capillaries?
They carry Oxygenated AND deoxygenated blood.
- Artery -> Arterioles
- Vein -> Venules
These connect to capillaries.
- They have LOW B.P
- NARROW LUMEN (allow rbc to pass through)
- NO VALVES
- Thin, permeable walls. (blood plasma can leak out and form tissue fluid, creating a medium for substances to diffuse in)
What are the components of Blood?
- Red blood cells: Transport O2
- White blood cells: Produce Antibodies + Phagocytosis
- Platelets: Help in blood clotting
- Plasma: Transport blood cells, ions, nutrients, urea, hormones, Co2
What are the types of WBCs?
Phagocytes: Engulf pathogens by phagocytosis.
Lymphocytes: Produce antibodies to attack the Antigen of pathogens using Active site to mark or ingest them.
What is the function of Platelets?
Platelets are fragments of cells present in blood.
- They clump together and form a plug to stop bleeding, and form a clot.
- Fibrinogen -> Fibrin to form a mesh.
- Platelets will stick to the mesh and form a scab to block the cut and prevent bleeding.
