B7.2

Question 1

What is the circulatory system?

Answer 1

A system of blood vessels with pumps and valves to ensure one way flow of blood

Question 2

What type of blood flows in veins and arteries (both systemic and pulmonary)?

Answer 2

Systemic
Veins -> deoxygenated
Arteries -> oxygenated

Pulmonary
Veins -> oxygenated
Arteries -> deoxygenated

Question 3

What is double circulation?

Answer 3

For every one lap around the body, blood passes through the heart twice

Question 4

Where does pulmonary circulation pump the blood?

Answer 4

Right side of heart pumps deoxygenated blood (via arteries) to the lungs where the blood becomes oxygenated and blood is returned to the heart (via veins)

Question 5

Where does systemic circulation pump the blood?

Answer 5

The left side of the heart receives oxygenated blood and pumps it around the body (from the lungs + via arteries) and picks up CO2 (excess + via veins)

Question 6

What are the advantages of double circulation?

Answer 6

Traveling through small capillaries in lungs help relieve pressure (allows slower movement and more efficient diffusion )

By going past the heart the pressure can be raised, allowing faster movement and can supply cells with oxygen and glucose faster/more often

Question 7

Draw and label the structures of the heart (ventricles, atria, muscular wall, septum, one way valves, coronary arteries)

Answer 7

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Question 8

What are the bicuspid and tricuspid valves?

Answer 8

Atrioventricular valves

Question 9

Why do ventricles have thicker muscle walls than the atria?

Answer 9

They need to pump blood out of the heart, so they need to generated a higher pressure

Question 10

What type of blood does the right side of the heart receive?

Answer 10

It receives deoxygenated blood from the body and pumps it to the lungs

Question 11

What type of blood does the left side of the blood receive?

Answer 11

The left side receives oxygenated blood from the lungs and pumps it to the body

Question 12

What does the left ventricle have a thicker muscle wall?

Answer 12

The left ventricle is responsible for pumping the blood throughout the entire body, meaning it needs to generate a higher pressure
The right only needs to pump the blood to the lungs, which are closer

Question 13

Whatt does the septum do?

Answer 13

The septum separates the two sides of the heart and prevents mixing of oxygenated and deoxygenated blood

Question 14

What are the function of valves?

Answer 14

The function of the valve is to prevent back flow/ the blood flowing backwards

Question 15

What are the names and functions of the atrioventricular valves?

Answer 15

The tricuspid (right side) and bicuspid (left side) separate the atria from the ventricles

The valves are pushed open when the atria contract
The valves are pushed up (closed) when the ventricles contract (prevent blood from going back into the atria)

Question 16

Where can the semilunar valves be found?

Answer 16

They are located at the two arteries the come out of the top of the heart (pulmonary artery and aorta)
Unusual because they are the only arteries that have valves

Question 17

What is the function of the semilunar valves?

Answer 17

Valves open when ventricles contract and blood is squeezed out of the heart
Valves close when atria contract and blood is stopped from flowing back into the heart

Question 18

What do the coronary arteries do?

Answer 18

The coronary arteries supplies blood (and therefore oxygen and nutrients+removes waste) to the (cardiac) muscle tissue which makes up the heart

Question 19

Why are coronary arteries necessary?

Answer 19

They give the muscles oxygen and nutrients and allows the heart to work at it best
The wall of the heart are so thick that oxygen and nutrients cannot easily pass through, hence the need for coronary arteries

Question 20

Which direction is the blood flowing in veins + arteries?

Answer 20

Vein -> to the heart
Arteries -> away from the heart

Question 21

Describe the path of blood through the body (emphasis on the contraction of muscles and action of valves)

Answer 21

Deoxygenated blood enters via vena cava into right atrium
Right atrium contracts and blood is pushed pass the tricuspid valve into the right ventricle
Right ventricle contracts and blood is pushed through the semilunar valve and into pulmonary artery (pressure prevents back flow)
Blood travels to the lungs and goes through capillaries (why blood has to slow/low pressure -> capillaries would burst) and past alveoli where gas exchange occurs
Oxygenated blood return to left atrium via pulmonary vein
Left atrium contracts and blood passes through the bicuspid valve into the left ventricle
Ventricle contracts and pushes the blood through the semilunar valve through aorta to the body (required high pressure-> thick muscles)

Question 22

Name the main blood vessels that go to and from the heart

Answer 22

To-> vena cava, pulmonary vein
Away-> aorta, pulmonary artery

Question 23

Name the main blood vessels that go to and from lungs

Answer 23

To-> pulmonary artery
Away-> pulmonary vein

Question 24

Name the main blood vessels that go to and away from kidneys

Answer 24

To->renal artery
Away-> renal vein

Question 25

What causes coronary heart disease?

Answer 25

Narrowing of the blood vessels to the heart (coronary arteries) reducing blood flow to heart If blood vessel is blocked -> part of heart might stop and become damaged (heart attack/cardiac arrest)

Question 26

What do the blood vessels become blocked by causing coronary heart disease? What does this cause in the blood vessels?

Answer 26

Fatty deposits called plaque (formed from cholesterol) Plaque makes arteries less elastic Arteries cannot stretch to accommodate blood which is being forced through -> coronary heart disease Partial blockage -> restricted blood flow and can cause severe chest pains called angina Full blockage -> cells in the area cannot respire and will die, so it cannot contract and leads to heart attacks

Question 27

What are risk factors/causes of coronary heart disease?

Answer 27

Male Older Smoker (blood vessels become narrower -> increase blood pressure) Overweight Inactive Stressed (increase blood pressure) Family history of CHD High cholesterol (produced in liver + obtained through diet/genetics, fatty acid -> cholesterol, reduce cholesterol -> vitamin A C E) High blood pressure (alcohol, too much salt etc) High intake of saturated fats (increases cholesterol) Diabetes

Question 28

How can coronary heart disease be prevented?

Answer 28

Quit smoking Diet-> reduce animal fats and eat more fruit+veg (reduces cholesterol) -> weight loss, decrease blood pressure, lower cholesterol and reduce stress

Question 29

What is pulse rate?

Answer 29

Heart/pulse rate -> how often you heart beats Measured by ECG or by listen to sound of valves opening using stethoscope Measured in beats per minute (bpm) -> average resting heart rate 70/75 bpm

Question 30

Investigate the effects of physical activity on heart rate

Answer 30

1. Record pulse at rest for 1 minute 2. Do some exercise 3. Record pulse rate after exercise every minute until it returns to the resting rate 4. Observe that pulse rate increase when you exercise and takes several minutes to return to a resting rate Effects: Heart rate increases Rate and depth of breath increases Arteries supplying blood to muscles dilate

Question 31

What are the effects of physical activity on the heart rate?

Answer 31

Increase heart rate mean that enough blood is supplied to the working muscle (oxygen + nutrients -> respiration) and that waste (CO2) can be removed faster Heart rate stays high after exercise to ensure that all waste product is removed Repay oxygen debt (from breathing anaerobically) and break down lactic acid

Question 32

Describe the structure of the arteries

Answer 32

Carry blood at high pressure from ventricles Carry blood away from the heart Narrow lumen (empty space in middle) Strong walls to withstand pressure Blood moves in pulses with each heartbeat (smooth muscles walls stretch and flex because of elastic fibers)

Question 33

Describe the structure and function of capillaries

Answer 33

Low pressure blood -> don’t burst Carry both oxygenated and deoxygenated blood Very small Takes nutrients and oxygen to cells and takes waste product (exchange/diffusion) Thin; permeable, one cell thick wall (good from diffusion)

Question 34

Describe the structure of veins

Answer 34

Carry blood at low pressure Thinner walls (doesn’t need to withstand much pressure) Large lumen-> to not slow the blood even more Valves in stop black flow of blood (muscles around veins push the blood, pressure pushes blood and opens valve)

Question 35

How are arteries adapted from their function?

Answer 35

Thick muscular wall with elastic fibers Withstand the high pressure of blood and maintain the pressure Narrow lumen Maintain pressure

Question 36

How are veins adapted to their function?

Answer 36

Large lumen Blood pressure low Valves Prevents back flow (because blood is under low pressure)

Question 37

How are capillaries adapted to their function?

Answer 37

Thin walls One cell thick-> diffusion Leaky walls Blood plasma can leak out and form tissue fluid surround the cells

Question 38

What are the components of blood?

Answer 38

55% plasma 45% red blood cells, white blood cells, platelets

Question 39

Identify platelets, white blood cells, and red blood cells under a light microscope, on diagrams photomicrographs

Answer 39

Light microscope/diagram Platelets -> small dot Red blood cell -> medium dots White blood cell -> big dot with smaller dots/one big dot inside Photomircographs Platelet -> small disc Red blood cell -> medium disc with small divot White blood cell -> fluffy looking ball

Question 40

What is the function of red blood cells (oxygen and haemoglobin)? (+ amount and shape)

Answer 40

5-6million /ml of blood Shape: Biconcave -> increase surface area so carry more oxygen No nucleus -> more space for oxygen Contains haemoglobin -> oxygen carrying molecule Function: Transport oxygen to the body from the lungs (required for aerobic respiration) (oxyhaemoglobin)

Question 41

What is the function of white blood cells? (+ amount and shape)

Answer 41

5000/ml of blood Shape: Larger than red blood cells Large flexible nucleus Part of immune system Different types have different functions and shapes Function: Body’s defense 2 types: phagocytes and lymphocytes Phagocyte: Monocytes and macrophages (types of phagocyte) Non-specific response to infection (surround and destroy pathogens (release digestive enzymes) -> phagocytosis) Has a sensitive cell surface membrane that can detect chemicals produced by pathogenic cells Lymphocyte: T-cells and B-cells (types of lymphocyte) Provide a specific immune response to infectious diseases Produce antibodies to destroy and antitoxins to neutralize toxins released Recognized by large round nucleus and clear nongranular cytoplasm

Question 42

What is the function of platelets? (+ amount and shape)

Answer 42

150,000-450,000/ml of blood Shape: Fragments of cells (some made in red bone marrow) Function: Clot blood to prevent blood loss and infection (scabs)

Question 43

What is the function of plasma?

Answer 43

Function: Liquid part of blood Transports: Soluble food molecules (glucose, amino acids) Waste product Hormones Antibodies Enzymes Etc

Question 44

What are the components of plasma?

Answer 44

Water Absorbed in small intestine and colon Goes to all cells Excess removed in kidneys Plasma proteins fibrinogens -> from liver (blood clotting) antibodies -> from lymphocytes (kill pathogens) Stays in blood Lipids (cholesterol and fatty acids) Absorbed in ileum (end of small intestine) or from fat reserves in body Goes to liver (breakdown adipose (for fat) tissue) or to storage (body fat) where it becomes an energy source Heart depends on fatty acids for energy Carbohydrates (glucose) Absorbed in ileum also produced by breakdown of glycogen in liver Goes to all cells (respiration) Extra glucose -> glycogen -> in liver Mineral ions (Na+, Cl-) Absorbed in ileum and colon Goes to all cells Excess are excreted by kidney Hormones Secreted into blood from endocrine glands Goes to all parts of the blood Will only affect target cells Broken down by liver and excreted by kidneys Dissolved gases (CO2) Waste produce of respiration Goes to lungs for excretion Most CO2 is carried as carbonate ions in plasma