Brainscapes- The haert

Question 1

Why do ventricles have thicker walls than the atria?

Answer 1

-Because they have to push blood out of the heart
-The atria push blood into the ventricles

Question 2

What does the atrioventricular valve prevent and what does it link?

Answer 2

-Prevents blood flowing from the ventricles (when they contract) back into the atria
-Links the atria and ventricles

Question 3

What does the semi-lunar valve do and what does it link?

Answer 3

-Stops blood flowing back into the heart when the ventricles contract
-Links ventricles, aorta and pulmonary artery

Question 4

What is the function of the cords?

Answer 4

-Attach the atrioventricular valves to the ventricles to stop them from being forced up into the atria when the ventricles contract

Question 5

Which sides pump oxygenated blood and deoxygenated blood?

Answer 5

Right= Deoxygenated
Left= oxygenated

Question 6

Where does _____ carry blood to and from
1.Pulmenary artery
2Pulmenory vein
3.Aorta
4.Vena Cava
5.Renal artery
6.Renal vein

Answer 6

1.heart - lungs
2. lungs - heart
3. Heart to body
4. Body to heart
5. body- kidney
6. Kidney to vena cava

Question 7

What does the blood transport?

Answer 7

-Respiratory gases
-Products of digestion
-Metabolic waste
-Hormones

Question 8

What is the heart’s blood supply?

Answer 8

-Right and left coronary arteries

Question 9

Relate the function to arteries

Answer 9

-Thick muscular walls to help the heart contract and maintain a high-pressure
-Muscular + elastcic to help stretch and recoil when the heart contracts
-The inner lining (endothelium) stretches

Question 10

What is the function of arterioles?

Answer 10

-Aetrioles contract/ relax to allow for restriction of blood flow or full flow

Question 11

What do arterioles branch into?

Answer 11

-Capaliries

Question 12

Relate the structure of capillaries to their function

Answer 12

-Substances such as glucose and oxygen are exchanged between cells
-Cepillaries are always found near cells in exchnage tissues as this gives them a shorter diffusion pathway (DP)
-They are only one cell thick so decrease DP
-Lots of capillaries to increase SA for exchnage

Question 13

What are capillary beds?

Answer 13

-Networks of capillaries throughout tissues

Question 14

What is the first step of the cardiac cycle (Systole)

Answer 14

-Ventricles relax
-Atria contact
-Pressure in chambers increases
-Volume in chambers increases
-Blood flows into ventricles

Question 15

What is the 2nd step of the cardiac cycle

Answer 15

-The atria relax
-Ventricles contract
-this increases pressure of the ventricles
-Forces AV to shut due to prevent backflow
-pressure higher in ventricles than pulmonary artery’s and aorta
-SL valves open
-Blood forced out of these artery’s

Question 16

What is the 3rd step of cardiac cycle?

Answer 16

-Atria relax
-ventricles relax
-PA and A relax
-Blood flows back to the heart
-SL valves close
-Atria begins to fill gain
-Pressure is increased in atria so AV valves open
-Pressure high in VC and PV so
-Pressure of ventricles is lower than aorta and PA so AV valves open
-Blood flows passively into ventricles

Question 17

What is stroke volume?

Answer 17

-Volume of blood pumped out with every beat (cm3)

Question 18

What is tissue fluid?

Answer 18

-Fluid surrounding the cells in tissues

Question 19

What does tissue fluid contain?

Answer 19

-Water
-Nuitrients
-O2
(small molecules leaving the blood plasma)

Question 20

Unlike blood, what does tissue fluid not contain?

Answer 20

-RBC/ large proteins as they are too large to go through the capillary wall

Question 21

What do cells take in from and release into tissue fluid?

Answer 21

Take in: O2 and nutrients
Release metabolic waste

Question 22

In a capillary bed, substances move out of capillaries and into tissue fluid by what process?

Answer 22

-Pressure filtration

Question 23

Explain how tissue fluid is formed.

Answer 23

-In the capillary bed, nearest the arteries, the hydrostatic pressure is greater inside the capillaries than the tissue fluid
-This means an overall force is exerted and the tissue fluid is pushed into the space surrounding cells #
-As fluid leaves the hydrostatic pressure is reduced so pressure much lower at the venule end

Question 24

Why is water potential lower at the venule end than the water potential of the tissue fluid?

Answer 24

-Fluid loss, increasing concentration of plasma proteins

Question 25

What happens due to water potential being lower at the venule end?

Answer 25

-Water reenters the caopilaries from tissue fluid via osmosis

Question 26

Where is excess tissue fluid drained to?

Answer 26

-Into the lymphatic system
-Transports excess fluid from the tissues and passes it back into the circulatory system

Question 27

What does high blood pressure lead to?

Answer 27

an accumulation of excess fluid in tissues

Question 28

Why is pressure highest nearest the arteries?

Answer 28

-pressure from the left ventricles contracting
-blood is sent out of the heart through the arteries +aerterioles

Question 29

Name some risk factors for cardiovascular disease

Answer 29

-High blood pressure
-High blood cholesterol
-Poor diet
-Smoking