B4 - Organising animals Flashcards
1
Q
What is a single circulatory system?
A
- Blood only passes once through the heart for each complete circuit in the body
2
Q
What is the heart?
A
The heart is an organ that pumps blood around the body in a double circulatory pump
3
Q
Why is the heart known as a double pump?
A
- Blood enters the heart twice for one circuit around the body
- Heart –> lungs —> heart –> body–> heart
4
Q
What is the heart made out of and what is it supplied with?
A
- Cardiac muscle tissue
- Supplied with oxygen by coronary artery
5
Q
How many chambers does the heart have?
A
- 4 chambers
- 2 atriums
- 2 ventricles
- blood goes from atrium to ventricles
6
Q
What is the function of the vena cava?
A
- Brings deoxygenated blood from body into the heart
7
Q
What is the function of the right ventricle?
A
- Pump blood to lungs(gas exchange)
8
Q
What is the function of the pulmonary artery?
A
- Transport deoxygenated blood from heart to lungs
9
Q
What is the function of the pulmonary vein?
A
- Transport oxygenated blood from lungs into heart
10
Q
What is the function of the left ventricle?
A
- Pumps blood around the body
11
Q
What is the function of the aorta
A
- Trasport oxygenated blood away from left ventricle into body
12
Q
What is the route of a blood cell through the heart? (9 steps)
A
- Vena cava with deoxygenated blood
- Pushed into right atrium which contracts
- Blood pumped into right ventricle which contracts
- Pumped into pulmonary artery
- Lungs where blood becomes oxygenated
- Blood leaves lungs through pulmonary vein
- Into left atrium with contracts
- Blood pumped into left ventricle which contracts
- Pumps blood into aorta which transports blood around the body
13
Q
What arteries give the heart its own oxygenated blood supply and what do they do?
A
- Coronary arteries : encircle the heart, makes sure all muscle tissue gets all nutrients and oxygen to keep contracting
14
Q
Why does the heart have atrioventicular valves?
A
- Prevent back flow of blood into previous chamber when they contract
15
Q
Why is the left side of the heart thicker?
A
- Has to pump blood all around the body at a high pressure so muscle is thicker there
16
Q
How is the resting heart rate controlled?
A
- Group of cells known as a pacemaker
17
Q
Where is this natural pacemaker found?
A
- Right atrium
18
Q
What are artifical pacemakers?
A
- Electrical devices used to correct irregularities in heart rate
19
Q
What is the function of arteries?
A
- Carry blood away from the heart
- At high pressure
20
Q
How are arteries adapted for their function?
A
- Thick elastic walls for high pressure
- Narrow lumen - maintain pressure
21
Q
What is the function of the veins?
A
- Carry blood to the heart
- At low pressure
22
Q
How are veins adapted for their function?
A
- Valves to stop back flow of blood
- Thin walls as blood at low pressure
- Large lumen - help blood flow
23
Q
What is the function of capillaries?
A
- Carry blood to tissues and cells
- Connects arteries and veins
24
Q
How is a capillary adapted for its function?
A
- One cell thick - short diffusion distance
- Permeable walls - substances can diffuse in and out
- Supply food and oxygen
25
Rate of blood flow equation?
Volume of blood/number of minutes
26
What do red blood cells do?
- Bind to oxygen and carry it around the body
27
How are red blood cells adapted?
- Biconcave shape for large surface area, fit through capillaries
- No nucleus for oxygen
- Haemoglobin to bind to oxygen
28
What does plasma do?
- Transports substances and blood cells around the body
29
What do platelets do?
- Small fragments of cells which form blood clots at wounds for a barrier to infection
30
What do white blood cells do?
- Defend the body against pathogens
- Change shape to ingest microbes
- Produce antibodies to fight microbes
- Produce antitoxins to neutralise toxins
31
What leads to coronary heart disease?
- A build up of fatty material in the coronary arteries
32
What does this disease do?
- Causes arteries to narrow, restricting blood flow and lack of oxygen to the heart
- Can lead to heart attack
33
What are stents and what are they used for?
- Tubes inside arteries
- To keep coronary artery open
34
What are 2 advantages of using stents?
- Lower the risk of having a heart attack
- Effective for a long time
35
What are 2 disadvantages of using stents?
- Risk of infection from surgery
- Patient can develop blood clot - thrombosis
36
What are statins used for?
- Lower cholesterol levels which slows down deposit of fatty material
37
What are 2 advantages of statins?
- Reduce risk of heart attack, strokes and coronary heart disease
- Increase good cholesterol
38
What are 2 disadvantages of statins?
- Long term drug
- Negative side effects like kidney failure
39
What are 3 advantages of mechnical valves?
- made of lightweight materials
- will last 20-30 years
- cheaper
40
What are 2 disadvantages of mechanical valves?
- likely that blood clots will form
- take thinning drugs
41
What are 2 advantages of biological valves?
- can last 10-20 years (save NHS money)
- no long-term use of medication
42
What is a disadvantage of biological valves?
- created from animal valves
43
What are artificial hearts used for?
- Temporary to allow someone's heart to rest and heal
- Less likely to be rejected by immune system because metal/plastic
- Surgical procedure can cause infection
44
Describe the journey of air into the lungs
- air goes down trachea
- trachea into two smaller tubes called bronchi
- bronchi split up into bronchioles
- bronchioles end in air sacks called alveoli
45
What is the function of alveoli?
- Gases diffuse in and out of blood stream
- Site of gas exchange
46
How are alveoli adapted?
- Thin walls - gases diffuse easily
- Many alveoli - huge surface area
- Moist lining - gases can dissolve
