4.4 Mammalian Systems

Question 1

List the 5 materials that need to be transported in mammalian systems:

Answer 1

• Nutrients
• Respiratory gases
• Wastes
• Hormones
• Heat

Question 2

What are the 4 features of an effective transport system?

Answer 2

• Large surface areas available for exchange both with and within the environment
• Reliable and responsive means of moving the fluid around the body
• Fluid the maximises the amount of material that can be transported (has a good carrying capacity)
• Control mechanisms that regulate the transport according to need

Question 3

What is the circulatory system?

Answer 3

• In simple multicellular organisms, such as hydra, nutrients and respiratory gases are transported by diffusion between cells
• In more complex organisms, the circulatory system is made up of either an open and closed system.

Question 4

In which mammals are open circulatory systems found and what are their function?

Answer 4

• Open circulatory systems are found in insects, snails, and spiders
• Fluid flows between cells of body tissues, then back to the heart
• Low pressure and long circulation times – pumps are weak and fluid doesn’t go directly to the heart

Question 5

In which mammals are closed circulatory systems found and what are their function?

Answer 5

• Are found in larger, more complex animals such as mammals
• The circulated blood, is enclosed within a system of vessels and is pumped around the body by the heart
• Allows high blood pressures so that blood can be returned to the heart rapidly

Question 6

What is intercellular fluid?

Answer 6

Cytoplasm fluid, inside cells

Question 7

What is extracellular fluid?

Answer 7

All fluid which is not inside cells

Question 8

What is interstitial fluid?

Answer 8

Extracellular fluid located between cells in tissues (tissue fluid)

Question 9

List the 2 transport systems in mammals:

Answer 9

• Blood circulatory system

- Lymphatic drainage system

Question 10

What is the blood circulatory system?

Answer 10

Is closed and provides for the majority of the animal’s transport needs.

Question 11

What is the lymphatic drainage system?

Answer 11

Is an open system that plays a vital role in maintaining water balance in tissues and in immune defences.

Question 12

List the 6 components of the blood circulatory system:

Answer 12

• Heart
• Veins and arteries
• Pulmonary vessels
• Systemic vessels
• Capillaries
• Blood

Question 13

What is the heart?

Answer 13

Muscular pump with two chambers is mainly responsible for moving blood throughout the circulatory system.

Question 14

What are veins and arteries?

Answer 14

Form a network of muscular channels carrying blood to and from the heart.

Question 15

What are pulmonary vessels?

Answer 15

Carry blood to and from all other parts of the body.

Question 16

What are systemic vessels?

Answer 16

Carry blood to and from all other parts of the body.

Question 17

What are capillaries?

Answer 17

Many thin-walled, channels which provide a large surface area for materials to be exchanged.

Question 18

What is blood?

Answer 18

The circulating fluid, which contains cells, and is highly specialised for transport and defence.

Question 19

Why does blood move in only one direction?

Answer 19

Because of the presence of 4 one-way valves.

Question 20

Which side of the heart has thick walls and why?

Answer 20

The left side of the heart because it takes higher pressure is used to pump the blood around the body.

Question 21

Which side of the heart has thin walls and why?

Answer 21

The right side of the heart because it takes less pressure to pump the blood to the lungs.

Question 22

Describe the 6 movements of blood through the heart:

Answer 22

1. Blood enters the right atrium through the systematic vein
2. The atrium contracts and blood flows through a valve into the right ventricle
3. The rising pressure in the ventricle causes the pulmonary artery to open and blood to flow through to the lungs
4. Blood become oxygenated and enters the left atrium via the pulmonary veins
5. The atrium contracts and blood flows through a valve into the left ventricle
6. The left ventricle pumps blood into the body through the aorta

Question 23

What is blood pressure caused by?

Answer 23

Is caused by the contraction of the ventricles, where higher systolic pressure occurs when the ventricle contracts, and lower diastolic pressure occurs when it relaxes.

Question 24

What are arteries?

Answer 24

• Carry blood away from the heart
• Have more muscular walls (higher pressure)
• Blood pressure is high (big difference between systole and diastole)
• Branch into smaller arteries called arterioles then capillaries

Question 25

What are veins?

Answer 25

• Carry blood towards the heart
• Are easily stretched
• Blood pressure decreases as closer to heart
• Blood moves through compression of vein by surrounding muscles
• Have valves so that blood can only flow one way

Question 26

What are capillaries?

Answer 26

• Narrow exchange vessels in between
• Thin walled of one cell (ease of exchange)
• Exchange between blood plasma and interstitial fluid occurs through diffusion

Question 27

Name the 3 types of blood:

Answer 27

• Plasma
• Red blood cells
• White blood cells

Question 28

What is plasma?

Answer 28

A pale yellow liquid, made up of ions, dissolved gases, proteins, hormones, nutrients, and wastes, that’s contents are determined by the lungs, kidneys, and liver.

Question 29

What are red blood cells?

Answer 29

Enterocytes, which lack a nucleus, and contain red pigment called haemoglobin which binds oxygen and transports it to the cell.

Question 30

What are white blood cells?

Answer 30

Leukocytes, which are involved in defence, and are larger and fewer than red blood cells.

Question 31

What are the 3 types of white blood cells?

Answer 31

• Phagocytes: Remove debris and fight infection
• Lymphocytes: Produce antibodies and develop immune response
• Platelets: Clotting response

Question 32

What are the 4 ways the body prevents blood loss?

Answer 32

1. Arteries in the area constrict to prevent blood moving to the area
2. Blood platelets stick together and form a plug
3. Blood coagulates (this is what haemophiliacs can’t do)
4. Growth of new tissues to permanently heal the wound