3.2 transport in animals

Question 1

What are arteries?

Answer 1

They carry blood away from the heart to the rest of the body. Their walls are thick and muscular and have elastic tissue to stretch and recoil as the heart beats to help maintain the high pressure.

Question 2

What are arterioles?

Answer 2

Smaller than arteries. They have a layer of smooth muscle but have less elastic tissue.

Question 3

What is a capillary?

Answer 3

Smallest type of blood vessels. Substances like glucose and oxygen are exchanged between cells and capillaries

Question 4

What are venules and what do they do?

Answer 4

They have very thin walls that can contain some muscle cells.

Question 5

What are veins?

Answer 5

They take blood back to the heat under low pressure. They have a wider lumen with very little elastic muscle tissue. Veins contain valves to stop backflow.

Question 6

What is a neutrophil?

Answer 6

They deal with defence against bacterial infections and other very small inflammatory processes and are usually first to respond. Their activity and death in large numbers form pus.

Question 7

What is an eosinophil?

Answer 7

They primarily deal with parasitic infections and an increase in them indicate such.

Question 8

What is a basophil?

Answer 8

Chiefly responsible for allergic and antigen response by releasing the chemical histamine causing inflammation.

Question 9

What is a lymphocyte?

Answer 9

B cells make antibodies. T cells coordinate the immune response. Natural killer cells are able to kill cells of the body which are not displaying a signal not to kill them as they have been infected by a virus or have become cancerous.

Question 10

What is a monocyte?

Answer 10

They share the “vacuum cleaner” function or neutrophils but are much longer lived as they have an additional role: they present pieces of pathogens to T cells so that the pathogens may be killed.

Question 11

What is a macrophage?

Answer 11

Monocytes after they migrate from the blood stream and enter tissue.

Question 12

What is the tunica intima?

Answer 12

Inner most part of the blood vessel. They reduce friction between the vessel walls and blood ; it is folded so that the vessel can stretch.

Question 13

What is tunica media.

Answer 13

Middle layer of blood vessel. Controls vasoconstriction and vasodilation.

Question 14

What is tunica externa?

Answer 14

outermost layer of the blood vessel. Protects, reinforces and anchors the vessel to surrounding structures.

Question 15

What does blood contain?

Answer 15

Mainly plasma - a yellow fluid containing water, glucose, urea, plasma proteins and ions. There are also RBCs and WBCs and thrombocytes.

Question 16

Where is tissue fluid found?

Answer 16

Surrounding the cells in tissues.

Question 17

What does tissue fluid contain?

Answer 17

Similar to blood plasma, but less oxygen, amino acids and glucose. Also contains a few WBCs.”

Question 18

Where is lymph found?

Answer 18

Inside lymph vessels. The largest is called the thoracic duct. Lymph enters the left arteriography vena cava.

Question 19

What does lymph contain?

Answer 19

Fats, salts, glucose and some proteins. Less O2 and more waste. No red blood cells or platlets but still clots. Contains WBCs and antibodies

Question 20

What is the movement of fluid based on?

Answer 20

Hydrostatic (caused by force of heart beat) and oncotic (dissolved solutes leading to osmotic/concentration gradients) pressure.

Question 21

What is the diastole phase?

Answer 21

The filling phase. The atria and ventricles are relaxed. Blood flows into the right and left atria. The valves are open and allow blood to flow into the ventricles. The sumi lunar valves are shut

Question 22

What is the systole phase?

Answer 22

The emptying phase. The ventricles contract, pumping blood out of the arteries. The semi lunar valves are open and the av valves are shut.