BIOLOGY - B2, Organisation, The heart Flashcards
What is ventilation?
The movement of air in and out of the lungs and enables large volumes of gas to be exchanged.
What are some adaptions of the alveoli?
Large surface area - More oxygen and carbon dioxide can be exchanged.
Thin walls - One cell thick providing gases with a short diffusion distance.
Moist walls - Gases dissolve in the moisture helping them to pass across the gas exchange surface.
Permeable walls - Allow gases to pass through
Good blood supply - Ensures oxygen rich blood is taken away from the lungs.
Learn the diagram of the respiratory system.
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What happens to the body when inspiration occurs?
- Ribs and sternum move up and out
- Diaphragm muscles contract and move downwards
- Thorax volume increases
- Gas pressure in the thorax decreases
What happens to the body when expiration occurs?
- External intercostal muscles contract
- Ribs and sternum moves down and in
- Diaphragm muscles relax and move upwards
- Thorax volume decreases
- Gas pressure in the thorax increases
Learn the diagram of the heart with the named valves.
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What is the pacemaker?
A group of cells located in the right atrium that regulates your heartbeat.
Arteries:
Takes blood where?
What is blood pressure like?
What adaptions does it have?
- Takes blood away from the heart.
- Carries blood under a high pressure.
- Thick walls allow the blood to travel at a high pressure.
Connective tissue provides strength.
The lumen is small which allows the artery to maintain the pressure of blood moving through the system.
Veins.
Takes blood where?
What is blood pressure like?
What adaptions does it have?
- Takes blood towards the heart.
- Low blood pressure.
- Lumen is large which allows a large volumes of blood to be stored.
- Thin walls allow more blood to flow with less resistance
What do these different blood components do?
- Red blood cells
- White blood cells
- Plasma
- Platelets
Red blood cells - carry oxygen around the body
White blood cells - Protects against infection by destroying microorganisms
Plasma - Carries dissolved substances
Platelets - Helps blood to clot
What are the adaptions of red, white blood cells and platelets?
Red blood cells
- They contain haemogoblin
- They have no nucleus
White blood cells
- Some can produce antitoxins and antibodies
Platelets
- Fragments of cells can form a ‘net’ to make clots form.
What is the equation for magnification?
Size of image/ Size of object
What is the thorax?
The space between the ribs and the diaphragm.
Learn the blood components diagram.
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What is coronary heart disease?
When plaque builds up in an artery due to a high level of cholesterol being consumed, blood flow is restricted as a result of this.
What does the coronary artery do?
Takes oxygenated blood to the heart muscle.
What are some of the risk factors of coronary heart disease?
- Poor diet
- Stress
- Smoking
- High cholesterol levels
- High blood pressure
- Genetic factors
- Lack of exercise
What are the pros and cons of statin tablets?
Pros:
- Can reduce the risk of a heart attack
- Reduces high cholesterol levels
- Can have beneficial effects on other conditions
Cons:
- Not suitable for people with liver diseases
- Must be taken for life
- Preventative only
What are some of the pros and cons of stents?
Pros:
- Short recovery time
- Local anesthetic
- Can be used if the artery hasn’t responded to drug treatment
Cons:
- Sometimes further treatment is required
- Risk of bleeding, heart attack or stroke
What do stents do?
Widens the coronary artery by inserting a metal balloon into it and inflating it widening the artery.
What is the process of ventilation?
Inhaling in breathing in and exhaling is breathing out.
When inhaling, the diaphragm muscle contacts and moves downwards.
The intercostal muscles contract and move the ribs upwards and outwards.
This increases the volume of the lungs, which reduces the pressure and so air moves into the lungs to equalise it.
When exhaling, the diaphragm muscle relaxes and moves upwards.
The intercostal muscles relax and move downwards and inwards.
This reduces the volume of the lungs, which forces air outwards.
