Mass Transport In Animals

Question 1

Why do humans have a circulatory system?

Answer 1

1.Small SA:Vol ratio so substances cant just diffuse in
2.high metabolic rate & very active so respire more
(higher 02 & glucose demand)
3.Hormones and enzymes produced by a gland in one part
of the body and are required in another part of the
body
4.Digested food, absorbed in the intestine, is required by
all cells in the body
5.Waste products of metabolism, produced by all cells,
need to be removed and disposed of in a particular part
of the body

Question 2

What is mass transport?

Answer 2

The bulk movement of substances in a fluid involving a mechanism of moving the fluid around the body.

Question 3

Why is mass transport helpful?

Answer 3

Quickly move substances from one exchange surface to another
Maintaining diffusion gradient
Keeps cells in suitable metabolic range - efficient cell activity

Question 4

What are the features of a circulatory system?

Answer 4

Liquid transport medium
Vessels to carry transport medium
Pumping mechanism

Question 5

What are the features of a closed circulatory system?

Answer 5

The transport medium is always enclosed in vessels.
Blood pigment to carry respiratory gases
Heart pumps under pressure
Blood pumped through progressively smaller tubes
Volume of blood transported can be adjusted.

Question 6

What is a single circulatory system?

Answer 6

Heart with two chambers , blood passes through once during each circuit.

Question 7

What is a double circulatory system?

Answer 7

Heart with four chambers, blood passes through twice for every circuit.

Question 8

Why are double circulatory systems used?

Answer 8

• most mammals = active so must maintain body temp
• most efficient way of transporting substances
• as blood travels through lungs the pressure decreases so would result in slow circulation
• only pass through one capillary network - high pressure

Question 9

What’s transported in the blood?

Answer 9

• Amino acids
• Oxygen
• Hormones
• Ions
• Platelets and fibrinogen
• Albumin
• Urea
• Glucose

Question 10

What does the smooth muscle layer do?

Answer 10

Contract to control blood flow

Question 11

What does the elastic layer do?

Answer 11

Allows the vessel to stretch and recoil

Question 12

What does the endothelium layer do?

Answer 12

Thin inner lining which is smooth to reduce friction in all vessels