Transport in Mammals

Question 1

The Circulatory system steps:

Answer 1

Deoxygenated blood enters from
1.Inferior vena cava
2.Right atrium
3.Tricuspid valve
4. Right ventricle
5. Semilunar/Pulmonary
6.Valve Pulmonary artery
7.Lungs ( here the deoxygenated blood turns into oxygenated blood RBCs take oxygen and release carbon dioxide)
8.Pulmonary vein
9.Left atrium
10.Bicuspid/Mitral valve
11.Left ventricle
12.Aortic valve
13.Aorta

Question 2

Structure of veins and adapted function :

Answer 2

Veins :
One way Valves : Prevent backflow of blood
Less elastin and smooth muscle : no need to stretch and recoil
Lots of collagen : provide strength and structure
Lumen is wide : The blood pressure is reduced in veins with no surges.

Question 3

The Role of Water in Circulation:
Compare and contrast the similarities and differences in the composition of tissue fluid and blood plasma.

Answer 3

Blood plasma and tissue fluid are both mainly composed of water.
-Water has high specific latent heat capacity
-Water acts as a solvent
- Water can transport dissolved substances in the blood like glucose.
This is because water is a small enough molecule to pass through the gaps in the capillary walls and into the tissue fluid.
Blood plasma and tissue fluid differ because blood plasma contains proteins, while tissue fluid does not. This is because proteins, such as albumin, are too large to fit between the gaps in the capillary wall and so they remain in the blood.

Question 4

Tissue fluid formation:

Answer 4

> When the blood enters the capillary, the hydrostatic pressure at the arterial end is high enough to push molecules out of the capillary.
The protein remain in the blood, the protein content creates a water potential b/w the capillary and blood (however the water is moved out of from capillary into tissue fluid)
the water potential b/w tissue fluid and capillary remain the same at arterial end and so water flows back in the capillary to the tissuefluid.
at the venous end less fluid is pushes out of the capillary as there is less pressure.
this way more fluid leaves than return, leaving the fluid to bathe cells.

Question 5

Suggest where glycosylation occurs in the cell and explain why mucin is packaged into
vesicles.

Answer 5

Gobelts cells
Mucin is produced in vesicles to the transport
the cell surface membrane through cytoplasm to golgi

Question 6

explain one feature that enables the surrounding body cells to
receive an adequate supply of oxygen from the blood supplied by the capillary.

Answer 6

Capillary wall is one cell thick allowing short distance for oxygen to move thru cells
Lumen of RBC and Capillary similar slowers the flow to allow sufficient oxygen to move to the cells

Question 7

Suggest one way in which the structure of a capillary in the blood-brain barrier differs from the normal capillary.

Answer 7

fewer, gaps / pores, in endothelium/ capillary wall