Circulatory system

Question 1

What are the functions of blood?

Answer 1

-transport O2 and nutrients to cells
-remove CO2 and wastes from cells
-transport chemical messages to cells (like hormones)
-maintain the pH of body fluids
-distribute heat and maintain body temperature
-maintain water content and ion concentration in fluids
-protect against microbes that cause disease

Question 2

What membrane covers the heart?

Answer 2

Pericardium
-holds heart in place
allows movement (beats)

Question 3

What are the chambers of the heart and their functions?

Answer 3

-Right atrium:
-receives blood from the body and passes it to the right ventricle
-through the tricuspid valve which stops it from flowing back into the right atrium

-Right ventricle:
-pumps blood to the lungs
-through pulmonary artery where the pulmonary valve stops blood flow back into the ventricle

-Left atrium:
-receives blood from the lung
-passes to the left ventricle through the mitral valve
-stops the backflow of blood into left atrium

-Left ventricle:
-pumps blood out of the heart
-to the rest of the body through the aorta, which house the aortic valve
-who’s function is to stop the blood from flowing back into the left ventricle

Question 4

Why is the left wall of the heart thicker?

Answer 4

It needs to be stronger and have that extra muscle to pump blood through the blood vessels to supply the oxygenated blood to the whole of the body.

Question 5

The Valves and their flaps?

Answer 5

Semilunar:
Valve preventing back flow of blood into the ventricles
E.g. pulmonary (3) and aortic

Atrioventricular:
Ensure blood flows though the heart in one direction only
E.g. tricuspid (3) and mitral (2)

Question 6

What is circulation?

Answer 6

The movement of blood through the heart and blood vessels.

Question 7

Phases of the cardiac cycle:

Answer 7

Pumping phase: (systole)
-heart contracts

Filling phase: (Diastole)
-heart relaxes

Question 8

What is the cardiac output equation?

Answer 8

cardiac output (mL/minute)=stroke volume (mL) x heart rate (beats/minute)

Question 9

What occurs in diastole?

Answer 9

-Heart relaxes
-For a short, both the atria and ventricles are in this phase
-Atria fill with blood and the ventricles receive blood as the valves between them open

Question 10

What occurs in atrial systole?

Answer 10

-the contraction of the atria following diastole
-blood is forced to flow in the ventricles
-atria then relax and refill

Question 11

What occur in ventricular systole?

Answer 11

-ventricles received blood forced out form atria
-contract
-force blood into the arteries

Question 12

What are the components of blood?

Answer 12

Plasma (55%)
Non formed element (45%)
e.g. erythrocytes, leukocytes, thrombocytes

Question 13

What is plasma’s function?

Answer 13

Transport components of blood, including cells, wastes, nutrients, hormones, proteins and antibodies, throughout the body

Question 14

What are erythrocytes and their function?

Answer 14

-red blood cells
-Transport oxygen from the lungs to the cells throughout the body

Question 15

What are thrombocytes and their function?

Answer 15

-platelets
-adhere to lining of damaged blood vessels and forms a scaffold for coagulation

Question 16

What are leukocytes and their function?

Answer 16

-White blood cells
-Protect the body from infection
Have five different types:
.neutrophils
.basophils
.monocytes
.eosinophils
.lymphocytes

Question 17

What are eosinophils?

Answer 17

Inflammatory response to protect against parasites

Question 18

What are monocytes?

Answer 18

Form other cells
e.g. macrophages that kill pathogens

Question 19

What are basophils?

Answer 19

Responsible for allergic reactions

Question 20

What are lymphocytes?

Answer 20

Involved in immune responses

Question 21

What is haematocrit?

Answer 21

Ratio of red blood cells to total volume of blood

Question 22

Why are red blood cells suited to their function?

Answer 22

-contain haemoglobin (combines with oxygen)
-no nucleus which allows for extra room for haemoglobin and can fit in vessels
-biconcave disk which increase SA of oxygen exchange and more space in edges for haemoglobin molecules

Question 23

What is haemoglobin?

Answer 23

-Pigment in RBC’s
-involved in the t5ransport of oxygen
-and carbon dioxide out of cell

Question 24

What is oxyhaemoglobin?

Answer 24

-formed from combo of oxygen and haemoglobin
-bright red in colour

Question 25

What is carbaminohaemoglobin?

Answer 25

-combo of carbon dioxide and haemoglobin

Question 26

What are the capillaries?

Answer 26

-link between veins and arteries
-suited to function due to one layer cells walls
-allow substances to pass through easily

Question 27

What are veins?

Answer 27

-carry blood to the heart
-constant low blood pressure
-thin, inelastic, little muscle walls
-will often have valves

Question 28

What are arteries?

Answer 28

-carry blood from heart to the body
-higher blood pressure as ventricles contract, lower if relaxed
-thick, elastic, muscular walls
-no valves

Question 29

What is the aorta?

Answer 29

Main artery that takes blood to all parts of the body (except lungs)

Question 30

What are the ways that carbon dioxide is carried in the blood?

Answer 30

-7-8% in the plasma
-20% combines w/ globin of haemoglobin which forms carbaminohaemoglobin
-70% carried in plasma as bicarbonate

Question 31

How are most nutrients and wastes transported in the body?

Answer 31

Dissolved and transported in the plasma

Question 32

Best way that oxygen is transported in the body?

Answer 32

Oxyhaemoglobin