8: Transport in Humans Flashcards

1
Q

Why do small organisms not need a transport system?

A

The substances are transported throughout their body by diffusion or streaming of the cytoplasm.

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2
Q

Why do large multicellular organisms need a transport system?

A

Cells in different parts of the body are far away from each other. Diffusion is too slow and becomes inefficient. Therefore, to ensure the supply of useful substances to target cells and removal of waste from the body, a transport system is developed in them.

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3
Q

What are the systems included in the human transport system?

A

Circulatory system, lymphatic system

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4
Q

What are the three main parts of the human circulatory system and their functions?

A

Blood: it carries useful substances and waste to and from body cells.
Blood vessels: they form a system of tubes that distribute blood throughout the body; the smallest blood vessels allow exchange of materials between blood and body cells.
Heart: it acts as a pump to give the force to drive blood throughout the body.

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5
Q

What are the four components of blood?

A

Plasma, red blood cells, white blood cells, blood platelets

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6
Q

What are the properties and functions of plasma?

A

Plasma contains mostly water with various substances dissolved or suspending in it.
It is the medium for transporting substances throughout the body, and it helps distribute heat throughout the body to maintain body temperature.

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7
Q

List 7 substances that the plasma transports.

A

Water, carbon dioxide (both as a gas and in the from of hydrogen carbonate ions), nutrients, urea, hormones, antibodies, and fibrinogen.

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8
Q

What are the shapes of red blood cells, white blood cells, and blood platelets?

A

Red blood cells have a biconcave disc shape, while white blood cells and blood platelets have irregular shape.

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9
Q

What are the sizes of red blood cells, white blood cells, and blood platelets?

A

Phagocytes are the largest type of cell, followed by lymphocytes and red blood cells having similar size. Blood platelets have the smallest size.

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10
Q

Rank the number per volume of red blood cells, white blood cells, and blood platelets in blood.

A

Red blood cells are the most abundant, followed by blood platelets and lastly white blood cells.

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11
Q

Compare the nuclei of mature red blood cells, white blood cells, and blood platelets.

A

Mature red blood cells and blood platelets have no nuclei. Phagocytes have a lobed nucleus while lymphocytes have a large round nucleus.

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12
Q

Rank the lifespan of mature red blood cells, white blood cells, and blood platelets.

A

Red blood cells have the longest lifespan, followed by blood platelets and lastly white blood cells.

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13
Q

Compare the colour of mature red blood cells, white blood cells, and blood platelets.

A

Mature red blood cells are red in colour due to the presence of haemoglobin. White blood cells and blood platelets are colourless.

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14
Q

Compare the sites of production and destruction of red blood cells, white blood cells, and blood platelets.

A

Red blood cells and blood platelets are produced in the bone marrow and destroyed in the liver and spleen. White blood cells are produced in the bone marrow and spleen; some of them are killed by germs and passed out through faeces.

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15
Q

What is haemoglobin in red blood cells broken down into?

A

Iron, which is reused to make red blood cells, and bile pigment, which is excreted as part of bile.

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16
Q

What are the characteristics of a blood smear of a patient with anaemia?

A

There is a reduced number of red blood cells, since anaemia is the deficiency of haemoglobin or red blood cells.

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17
Q

What are the characteristics of a blood smear of a patient with leukaemia?

A

There is an increased number of white blood cells, since leukaemia usually leads to the production of a large number of abnormal white blood cells.

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18
Q

What is the function of red blood cells?

A

They contain haemoglobin which carries oxygen from the lungs to all parts of the body.

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19
Q

What is the function of white blood cells?

A

They protect our body against diseases by killing germs.

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20
Q

What is the function of blood platelets?

A

They are involved in blood clotting which prevents further blood loss and the entry of germs into our body through the cut wounds.

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21
Q

What are 5 types of blood vessels in humans?

A

Arteries, arterioles, capillaries, venues, and veins

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22
Q

What is the largest artery in humans?

A

Aorta

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23
Q

What is the largest vein in humans?

A

vena cava

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24
Q

What are the layers of the walls of arteries and veins?

A

There are 4 layers:
The outer layer is fibrous tissue, the middle layers consist of smooth muscles and elastic tissues, while the inner layer is the endothelium.

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25
What are the differences in thickness of the layers of the walls of arteries and veins?
Arteries have a thicker layer of **smooth muscles and elastic tissue** and a **smaller lumen**, while veins have a thinner layer of smooth muscles and elastic tissue and a larger lumen.
26
What is the significance of the thick wall of arteries?
They allow the arteries to **withstand high blood pressure** *due to the pumping action of the heart*.
27
How does the thick layer of elastic tissues in arteries maintain a continuous blood flow?
The thick layer of elastic tissue of the arteries allows them to **distend and recoil**. When the heart relaxes, the arteries **recoil** due to the elasticity of their walls, which causes the blood to flow forward.
28
How is the amount of blood flow to different parts of the body regulated?
In the **arterioles**, the thick layer of muscles **contract or relax** to **change the size of the lumen**. This regulates the amount of blood flow to different parts of the body.
29
What is the significance of the large lumen of veins?
They reduce the **resistance to the blood flow** inside the veins.
30
How is a continuous forward blood flow maintained in the veins?
**Valves** are present in veins to prevent **the backflow** of blood. The force for blood flow in veins is mainly provided by the **contraction of skeletal muscles** lying next to the veins. When the muscles contract, the veins are **squeezed** and the blood is forced to flow towards the heart.
31
Compare the locations of arteries and veins.
Arteries are located deep inside the body while veins are located closer towards the body surface.
32
Compare the directions of blood flow of arteries and veins.
Arteries carry blood away from the heart while veins carry blood towards the heart.
33
Compare the sources of the force for blood flow in arteries and veins.
The force for blood flow in arteries is provided by the **pumping action of the heart**. The force for blood flow in veins is provided by the **contraction of skeletal muscles** that squeeze the vein.
34
Compare the blood pressure in arteries and veins.
The blood pressure in arteries is higher due to the **pumping action of the heart**. The blood pressure in veins is lower, since the blood has flowed for a **long distance** and **has overcome great resistance** of the walls of blood vessels.
35
In which artery / arteries is deoxygenated blood transported?
Pulmonary artery, umbilical artery
36
In which vein / veins is oxygenated blood transported?
Pulmonary vein, umbilical vein
37
What are the features of capillaries?
Their lumen is only slightly larger than the diameter of a red blood cell. The capillary wall is made up of **one-cell thick endothelium**, which is **differentially permeable**. There is no muscle layer in the capillary walls.
38
List 3 ways in which capillaries are adapted for the exchange of materials between the blood and body cells?
1. The capillary bed is **highly branched**, which provides a **large surface area** for **rapid exchange** of materials *between the blood and body cells*. 2. Each artery eventually branches into a very large number of capillaries. The **total cross-sectional area** is much greater in the capillary beds than in any other part of the circulatory system. Blood flows **slowly** in the capillaries, which allows a **longer time for exchange** of materials *between the blood and body cells*. 3. The **one-cell thick** capillary wall provides a **short distance** for the rapid diffusion of materials *between the blood and body cells*.
39
What is blood pressure?
Blood pressure is the force exerted on the wall of the blood vessel by the blood flow per unit area.
40
Explain the blood pressure in arteries and arterioles.
Blood pressure is **high** due to **the pumping action of the heart**. It also changes **periodically** as the heart contracts and relaxes.
41
Explain the blood pressure in capillaries.
The blood pressure in capillaries **drops significantly** compared to that in the arteries and arterioles. The **small diameter** of the capillaries results in a **high resistance to blood flow**, so the blood pressure has a significant drop.
42
Explain the blood pressure in veins and venules.
The blood has **overcome great resistance** of the blood vessel walls after travelling a **long distance** from the heart. The blood pressure drops to nearly zero.
43
Explain the rate of blood flow in arteries and arterioles.
The rate of blood flow in the arteries is **high** due to **the pumping action of the heart**. When the arteries branch into arterioles, the **total cross-sectional area** of the arterioles **increases**, so the flow rate drops.
44
Explain the rate of blood flow in capillaries.
The **total cross-sectional area** of capillaries is the greatest in the circulatory system. The rate of blood flow drops to nearly zero, providing more time for the exchange of materials *between the blood and body cells*.
45
Explain the rate of blood flow in veins and venules.
The force from the pumping heart can no longer drive blood forwards. The rate of blood flow **increases** due to the **contraction of skeletal muscles** lying next to the veins, and the **decrease in total cross-sectional area** of veins and venules compared to capillaries.
46
State the membrane and tissue surrounding the heart.
Pericardium and pericardial fluid
47
State the function of the pericardial fluid.
It **reduces friction** within the pericardium by allowing the membranes to glide over each other with each heartbeat.
48
Where does blood in the anterior vena cava flow from?
The upper body
49
Where does blood in the posterior vena cava flow from?
The lower body
50
State the names of the main chambers in the heart.
Left atrium, left ventricle, right atrium, right ventricle
51
State the location of the coronary arteries and coronary veins.
They lie on the surface of the heart.
52
State the functions of the coronary arteries and coronary veins.
The coronary arteries supply oxygen and nutrients to the **cardiac muscles** and the coronary vein carry carbon dioxide and other waste away from the cardiac muscles.
53
State the relative locations of atriums and ventricles.
The atria are the **upper chambers** while the ventricles are the **lower chambers** in the heart.
54
State the blood vessel(s) connected to the right atrium.
Anterior vena cava, posterior vena cava
55
State the blood vessel(s) connected to the left atrium.
Pulmonary veins
56
State the blood vessel(s) connected to the left ventricle.
Aorta
57
State the blood vessel(s) connected to the right ventricle.
Pulmonary artery
58
State the difference in the blood in the left side and the right side of the heart.
The left side of the heart receives **oxygenated blood** while the right side of the heart receives **deoxygenated blood**.
59
State the function of the septum.
It prevents the **mixing** of oxygenated and deoxygenated blood in the two sides of the heart.
60
Compare the thickness of the muscular wall of atria and ventricles.
The atria have a **thinner muscular wall** than the ventricles.
61
Compare the blood pressure in the blood vessels connected to the atria and ventricles respectively.
The atria receive blood at a **low blood pressure** from **veins**. The ventricles pump blood out to **arteries** at **high blood pressure**.
62
Explain the difference in thickness of muscular wall of the ventricles.
The muscular wall of the **left ventricle** is **thicker** than that of the right ventricle. This ensures that the left ventricle can **provide greater force** to pump blood a longer distance away compared to the right ventricle, to all parts of the body except the lungs.
63
State the name of the heart valve between the right atrium and the right ventricle.
Tricuspid valve
64
State the name of the heart valve between the left atrium and the left ventricle.
Bicuspid valve
65
State the name of the heart valve between the right ventricle and the pulmonary artery.
Semilunar valves
66
State the name of the heart valve between the left ventricle and the aorta.
Semilunar valves
67
State the function of heart tendons.
They **hold heart valves in place**, and prevent the valves from **turning inside out** when the ventricles contract.
68
State the direction of blood flow prevented by the bicuspid valve.
The backflow of blood from the **left ventricle to the left atrium** *when the left ventricle contracts*.
69
State the direction of blood flow prevented by the tricuspid valve.
The backflow of blood from the **right ventricle to the right atrium** *when the right ventricle contracts*.
70
State the direction of blood flow prevented by the semilunar valves.
The backflow of blood from the **pulmonary artery to the right ventricle, and from the aorta to the left ventricle** *when the ventricles relax*.
71
Label the diagram below from 1 to 4:
1. Anterior vena cava 2. Right atrium 3. Tricuspid valve 4. Posterior vena cava
72
Label the diagram below from 5 to 8:
5. Semilunar valves 6. Right ventricle 7. Aorta 8. Pulmonary artery
73
Label the diagram below from 9 to 13:
9. Left atrium 10. Pulmonary vein 11. Bicuspid valve 12. Left ventricle 13. Semilunar valves
74
State the names of the double blood circulation in our body.
Pulmonary circulation and systemic circulation
75
Describe the blood flow in the pulmonary circulation.
**Deoxygenated blood** in the right atrium flows to the right ventricle. The contraction of the right ventricle pumps the blood to the lungs via the **pulmonary artery**. As **gas exchange** takes place in the lungs, the blood becomes **oxygenated** and returns to the **left atrium** by the **pulmonary veins**.
76
Describe the blood flow in the systemic circulation.
**Oxygenated blood** in the left atrium flows to the left ventricle. The contraction of the left ventricle pumps the blood to **all parts of the body except the lungs** through the **aorta**. In the capillary beds, exchange of materials takes place between blood and body cells. The blood becomes **deoxygenated** and returns to the **right atrium** through the **anterior vena cava and posterior vena cava**.
77
State an exception of a human organ which receives blood from two blood vessels.
The liver, which receives blood from the **hepatic artery** and the **hepatic portal vein**.
78
State the function of the hepatic portal vein.
It links the **small intestine** to the **liver**. After digestion, nutrients absorbed in the intestine enter the blood. The nutrient-rich blood is collected by the **hepatic portal vein** ad passed to the liver. It then flows through the hepatic vein and the posterior vena cava to the heart.
79
State one example of an animal with single circulation.
Fish
80
Describe the exchange of oxygen and nutrients between blood and body cells.
The exchange of these materials take place in the **capillary bed**, with the walls of the capillarities being **differentially permeable**. At the capillaries, these molecules are forces out of the capillary wall into the **tissue fluid**. They then **diffuse** from the tissue fluid into the body cells.
81
Describe the exchange of waste between blood and body cells.
Waste products from the body cells **diffuse** from the body cells **into the tissue fluid**. Then, they diffuse across the differentially permeable capillary wall into the blood.
82
Describe the process of the formation of tissue fluid at the arteriole end of the capillary.
At the arteriole end of the capillary bed, the pressure of the blood in the capillaries is higher than the **hydrostatic pressure** surrounding the body cells. The **difference in hydrostatic pressure** forces small molecules in the plasma like water to **exit the capillary walls** to form tissue fluid.
83
Explain the difference in composition between tissue fluid and blood.
Plasma proteins, red blood cells, blood platelets, and lymphocytes, are **too large** to pass through the capillary walls, so they **remain in the blood**. The composition of tissue fluid is similar to that of blood except for the absence of red blood cells, blood platelets and plasma proteins.
84
Describe the process of the return of tissue fluid at the venule end of the capillary.
As plasma proteins remain in the blood, the **water potential** of the blood at the venule end of the capillaries is **lower** than that of tissue fluid. Therefore, water in the tissue fluid is **drawn from the spaces between body cells into the capillaries** *through the differentially permeable capillary wall* by **osmosis**.
85
Describe the process of the formation of lymph.
Due to **hydrostatic pressure** of the tissue fluid, a small amount of tissue fluid drains into the **lymph capillaries**, which carry the excess tissue fluid back to the blood circulation.
86
State two importances of tissue fluid.
1. It provides a relatively **constant environment** for the normal functions of the body cells. 2. Tissue fluid serves as an important **link** for the **exchange of materials** between the blood in the capillaries and body cells.
87
State six structures of the lymphatic system.
Lymph, lymph vessels, lymph nodes, thymus, spleen, tonsils
88
State the composition of lymph.
It has the **same composition as tissue fluid**. It has a similar composition as blood except with the **absence of red blood cells, blood platelets, plasma proteins, and lymphocytes**.
89
State two properties of lymph vessels.
They are **blind-ended** vessels with **valves**.
90
State how a continuous flow of lymph is created.
Lymph is kept flowing slowly by contraction of skeletal muscles lying next to the lymph vessels. Valves are present in the lymph vessels to prevent the backflow of lymph.
91
State two functions of the spleen.
It filters damaged cells and germs in the blood, and produced and stores **which blood cells**.
92
State one function of the thymus.
It produces and stores **white blood cells** which kill germs and destroy dead cells in the blood.
93
State one function of the tonsils.
They consist of **which blood cells** to guard against germs that enter the mouth or nose.
94
State three functions of the lymphatic system.
1. It collects and returns **excess tissue fluid** to the blood circulation. 2. It protects us against disease. 3. It transports lipids from the **lacteals in the villi of the small intestine** into the blood.
95
State how the lymphatic system protects us against disease.
White blood ells in lymph nodes **kill germs** that enter the lymphatic system. Germs are **filtered out** from the lymph before the lymph s returned to the blood.