Chapter 6 - Transport & Form Cells

Question 0

Blood as a Transport Medium

55% Blood Plasma but what’s the rest?

Answer 0

Formed Elements; Erythrocytes (RBC), Leucocytes (WBC) and Platelets.

Question 1

What is the main function of the Blood?

Answer 1

The blood is a transport medium that delivers O2 and nutrients to cells and carries away their wastes.

Question 2

Distribution of transportation of Oxygen.

Answer 2

• 3% of Oxygen is carried in solution in the blood plasma.

* 97% is carried in combination with haemoglobin molecules that are found in RBC.

Question 3

Oxyhaemoglobin can easily be broken down to release Oxygen.

Answer 3

Haemoglobin + Oxygen -> Oxyhaemoglobin

Hb + O2 -> HbO2

Question 4

How does Oxyhaemglobin take place?

Answer 4

Oxygen combines with haemoglobin when the concentration is relatively high but it breaks down to release Oxygen when the concentration of Oxygen is relatively low.

Question 5

Why is an Erythrocyte good for Oxygen transport?

Answer 5

• Contains Hb to combine with O2
• No nucleus = more room for Hb
• Biconcave-disc shaped, increases surface area for O2 exchange
• Thicker edges give a large volume that allows room for Hb

Question 6

Distribution of transportation of Carbon Dioxide:

Answer 6

• 7-8% dissolved in blood plasma
• 22%+ combines with gloving part of Hb to form Carbaminohaemoglobin
• 70% carried in the plasma as bicarbonate ions (HCO2)

Question 7

Carbon Dioxide + Water -> Carbonic Acid -> Hydrogen ion + Bicarbonate Ion

Answer 7

CO2 + H2O -> H2CO3 -> H+ + HCO3-

Question 8

What is the Membrane around the heart?

Answer 8

The Pericardium is the walls of the ❤️ made up of cardiac muscle. It holds the ❤️ in place but allows it to move/beat and it prevents the ❤️ from over stretching.

Question 9

What is the function of blood vessels?

Answer 9

Blood vessels carry blood to the cells of the body/lungs and then bring it back to the ❤️ again.

Question 10

What is the function of a Leucocyte?

Answer 10

Leucocytes can remove dead or injured cells and invading micro-organisms.

Question 11

What is the function of Platelets/ Thrombocytes?

Answer 11

They are important for normal blood clotting.

Question 12

The Cardiac Cycle:

Answer 12

1. Systole
2. Diastole
3. Arial Systole
4. Ventricular Systole

Question 13

What happens at Systole?

Answer 13

Pumping phase of the cycle, when the cardiac muscle contracts.

Question 14

What happens at Diastole?

Answer 14

Filling phase as the cardiac muscle relaxes, during this phase the atria fill with blood and the ventricles so receive blood dad the valves between them open.

Question 15

What happens at Arial Systole?

Answer 15

The contraction of the atria, then follows and forces the remaining blood into the ventricles.

Question 16

What happens at Ventricular Systole?

Answer 16

The Atria relax and refill while the ventricles contract which forces the blood into the arteries.

Question 17

Define Stroke Volume.

Answer 17

Volume of blood forced from a ventricle of the heart with each contraction.

Question 18

Define Cardiac Output.

Answer 18

The amount of blood leaving one of the ventricles every minute.

Question 19

Cardiac Output Formula:

Answer 19

Cardiac Output = Stroke Volume x Heart Rate

mL = mL x beats/minute

Question 20

Characteristics of Arteries:

Answer 20

• Blood away from the ❤️
• Walls are made up of smooth and elastic fibers
• Stretch to accommodate extra blood

Question 21

Define Vasoconstriction.

Answer 21

Muscle contracts to reduce the diameter of the artery and thus reduce blood flow to an organ.

Question 22

Define Vaslolidation.

Answer 22

The muscle may relax to increase blood flow to an organ.

Question 23

Characteristics of Arterioles.

Answer 23

• Very small arteries
• Supply blood to the capillaries
• Smooth muscle in their walls

Question 24

Function of Veins.

Answer 24

• Carry blood towards the ❤️
• Do not have muscular walls
• Cannot change their diameter

Question 25

Function of Venules.

Answer 25

• Tiny Veins
• Carry blood away from the capillaries
• Cannot change their diameter

Question 26

What is a Sinoatrial Node?

Answer 26

The SA node is a collection of nerve cells located in the right atrium. It acts as a pacemaker for the ❤️.

Question 27

How does the SA node work?

Answer 27

It begins each Cardiac cycle with nerve impulses that spread out over the atria causing them to contract.

It’s activities are influenced by the nervous system.

Question 28

Factors influencing the Arteriole diameter:

Answer 28

• Cardiovascular regarding centre in the brain.

* Various hormones; Adrenaline

Question 29

What’s the function of the Adrenaline?

Answer 29

It causes Vasoconstriction of most arteriole but in the skeletal muscles and the ❤️ muscle it causes Vasolidation.

Question 30

Tissues are able to regulate their own blood supply.

True or False.

Answer 30

True.

Question 31

What happens when the skeletal or ❤️ muscle has an inadequate blood flow?

Answer 31

It’s waste products will accumulate, which will stimulate Vasolidation. This will increase oxygen supply and removal of the waste products.

Question 32

What happens to the blood flow during exercise?

Answer 32

To ensure that blood supply to the muscles is increased, the nervous system and the hormone adrenaline cause constriction of the blood vessels in internal organs such as the stomach and intestine. That is accompanied by a dilation of blood vessels in the muscles.