B2 Flashcards
What does anaerobic respiration mean
Without oxygen- incomplete breakdown of glucose making lactic acid
When does anaerobic respiration occur
When you do vigorous exercise and your body can’t supply enough oxygen to your muscles
In anaerobic respiration glucose isn’t…
Fully oxidised
Formula for glucose turning into lactic acid
C6H12O6→ 2C₃H₆O₃ + 2ATP
What is meant by the term oxygen debt
Oxygen has to be repayed
- needed to remove waste build up of lactic acid in cells when oxygen didn’t get to muscles in time
What is bronchus
Plural for bronchi - two tubes down from trachea
Define Bronchioles
Progressively smaller tubes from bronchus
What is metabolism
All chemical reactions in an organism
Explain how lungs are adapted for gaseous exchange. Do not refer your answer to alveoli
Lungs are ventilated so that a new supply of air is constantly bought in
Describe how alveoli are adapted for gaseous exchange ( 6 marks)
- folded- increases s.a. (75 m²) let’s a larger volume of gases to be diffused at once
- thin membrane (walls are one cell thick) speeds up rate of diffusion by decreasing distance over which it occurs- creating short diffusion pathway
- rich blood supply, surrounded by network of capillaries - takes things from and to exchange surface efficiently
MAXIMISES GAS EXCHANGE RATE
Define thorax
Top part of your body separated from lower half by the diaphragm
Word equation for aerobic respiration
Glucose + oxygen ===== carbon dioxide + water
- energy is released
What is the formula for aerobic respiration
C6H12O6+ 6O2→ 6CO2+ 6H2O
How are arteries designed for their function (5)
Direction of flow:
Oxygenated or deoxygenated:
Pressure:
Wall structure:
Lumen:
- blood flows away from heart
- Oxygenated blood except pulmonary artery
- high pressure
- thick, elastic, muscular connective tissue for strength
- narrow Lumen- channel inside vessel
How are veins adapted for their function (5)
Direction of flow:
Oxygenated or deoxygenated:
Pressure:
Wall structure:
Lumen:
- blood flows towards the heart
- dexygenated except pulmonary vein
- low (negative) pressure
- thin, less muscular, less connective tissue
- wide Lumen with valves
Describe the 3 types of blood vessels
Arteries= carry blood away from the heart
Veins= carry the blood to the heart
Capillaries= are involved in the exchange of materials at the tissue
Define cardiac output
A measure of the volume of blood pumped by the heart each minute
Define stroke volume
A measure of the volume of the blood pumped from the heart each contraction (heart beat)
What is the equation of cardiac output
Cardiac output = stroke volume × heart rate
Q = (cm³/mm)
SV= (cm³/beat)
HR= (bpm)
What does SAN stand for
sino- atrial node
What does AVN stand for
Atrio- ventricular node
Function of SAN
Located near right atrium and stimulates atria to contract
Function of AVN
Located between ventricles and stimulates them to contract
What are pacemakers
Small group of cells located in muscular walls of heart that produces electrical impulses which stimulate surrounding muscle to contract , squeezing chambres of heart and pumping blood
The rate of the heart beating is very carefully and automatically controlled by…
Pacemaker cells within wall of right atrium
Why does the left ventricle have a muscular wall
Muscular wall of left ventricle is much thicker so it can pump blood more forcefully out of the heart and around the entire body via aorta
Describe coronary heart disease
Coronary arteries that supply blood to muscles of the heart get blocked by layers of fatty material build up
Causes arteries to become narrow so blood flow is restricted and there’s a lack of oxygen to heart muscle- can result in heart attack
What is the role of vena cava
Transport blood to lower part of body and drain deoxygenated blood to heart
What do red blood cells do
Job of red blood cells is to transport/ carry oxygen from the lungs to the rest of the cells in the body
How are RBC adapted for function
- shape is biconcave disc- gives large surface area for absorption of oxygen and flexibility of fitting into tiny capillaries
- no nucleus gives them more area to fit haemoglobin in- which binds to oxygen in the lungs and reverse happens in body tissue- breaks up to give oxygen to cells
- ## contain red pigmented protien called haemoglobin
Formula for oxygen and haemoglobin
Oxygen + Haemoglobin=====Oxyhaemoglobin
4O2+ Hb===== Hb4O2
What are the main symptoms of coronary disease
Chest pain
Heart attack
Heart failure
- not everyone however suffers same symptoms
What increases chances of getting CHD
Lifestyle factors:
- diet
- stress
- smoking
How does diet increase chances of getting CHD
A high fat diet (containing a lot of saturated fat) can lead to higher cholesterol levels- these cholesterol form fatty deposits which damage + block arteries
How does stress increase chances of getting CHD
Stress- prolonged exposure to stress or stressful situations (such as high preassured jobs) can lead to higher blood pressure and an increased risk of heart disease
How does smoking lead to increase chances of getting CHD
Carbon monoxide reduces volume of oxygen which can be transported by red blood cells, nicotine causes increased heart rate
Lack of oxygen to the heart and increased pressure can lead to heart attacks
Define pulse
Number of beats the heart performs each minute ( also called heart rate)
What does pulse rate indicate
Lower resting pulse rate indicates greater level of physical fitness
During exercise+ some time after pulse rate increases while heart is working to provide more oxygen to the muscles
Advantages of pacemaker
Mimics natural actions- will regulate the heart if beating too slow or too fast
Biventicular pacemaker- works to ensure ventricles +atria are working together
- improves heart pumping efficiency in patients who have had lower heart damage from heart failure
Disadvantage of pacemaker
Although minor surgical procedure there is risk of infection at surgery location
- you will have a battery operated metal device in your chest that is sensitive to electrical impulses internally and externally- any medical procedures using electromagnetic field can interfere with pacemaker
The hearts works as a double pump for…
2 circulatory systems: systematic circulation, pulmonary circulation
What is pulmonary circulation
Serves the 🫁 and brings deoxygenated blood to exchange waste C0² gas for O² at alveoli
What is systematic circulation
Serves rest of body- transports oxygen + nutrients from digestion to cells of body whilst carrying waste C0² away from cells
- blood flows through whole body meanning blood is flowing at a much higher pressure than in pulmonary circuit
Pulmonary and systematic circulations are both..
Circuits
What is the word that is plural for atrium
Atria
Describe function of human heart
● Large muscular organ which pumps blood carrying oxygen/ waste products around body- mostly made up of muscle tissue
Describe how human heart pumps blood around body
● blood flows into the two atria from the vena cava and pulmonary vein
● atria contract pushing blood into ventricles
● ventricles contract forcing blood into pulmonary artery and the aorta and out of the heart
● atria fill again and cycle repeats
Why does the heart have valves
Make sure blood flows in the right direction and prevent it from flowing backwards
Why might valves need replacing
♡ Damaged- May cause valve tissue to stiffen (won’t open properly)
♡ Weakened by heart attacks
♡Infection
♡ Old age
♡ may become leaky- blood flows in both directions- meanning it doesn’t circulate as effectively as normal
How can severe valve damage be treated
By replacing valve, can be taken from humans, other mammals or mechanical
Risks of replacing valve
Much less drastic than whole heart transplant- however it is still a major surgery and can still cause problems with blood clots
What is a stent
Mechanical device (tube) inserted inside arteries used to stretch narrow or blocked arteries restoring blood flow- makes sure blood can pass through to the heart muscles- keeps heart beating, patient stays alive
Advantages of stent
Lowers risk of heart attack in people with CHD
- used for patients where drugs are less effective
- offers long term benefits and quick recovery time
- made from metal alloys so will not be rejected by patients body
- improved quality of life
What are disadvantages of stents
-Requires surgery under general anaesthetic- carries risk of infection
- risks of complications during heart operation e.g heart attack
- risk of patient developing blood clot near stent- thrombosis
Define plasma
Pale straw coloured liquid that carries everything in the blood
What does plasma carry
- RBC, WBC, platelets
- nutrients like glucose and amino acids- soluble product of digestion absorbed from gut taken to cells of body
-Carbon dioxide from organs to blood - urea from liver to kidneys
- hormones
- proteins
- anti bodies and anti toxins produced by WBC
What is blood
Tissue consisting of plasma in which RBC, WBC and platelets are suspended
What are artificial pacemakers
Electrical device used to correct irregularities in heart rate
How is the natural resting heart rate controlled
By a group of cells located in the right atrium wall that act as a pacemaker
What do statins do
Reduce cholesterol in blood
What is cholesterol
Essential lipid your body produces and needs to function properly
However too much of LDL cholesterol (bad cholesterol) can result in health problems
What does LDL cholesterol do
Too much in blood stream can cause fatty deposits to form inside arteries- which can lead to CHD
What is CHD an abbreviation of
Coronary heart disease
What is the function of statins
Drugs which can reduce amount of bad cholesterol present in blood stream- slows down rate of fatty deposits forming
What is a heart transplant
Entire organ replaced by one from organ donor
Who is an organ donor
A person who has died and previously expressed a wish for their organ to be used in a particular way
Advantages of heart transplant
- Can treat complete heart failure in person
- Extended life
- Improved quality of life
What can be used temporarily until heart donor is found
Artificial plastic hearts
Disadvantage of heart transplant
- requires major surgery under general anesthetic which carries risks
- lack of donours available
- risk of infection from transplant
- risk of transplant rejection
- long recovery time
Why is salline a good substitute of blood
When someone loses a lot of blood, heart can still pump remaining blood around body (to get oxygen to organ) - as long as volume of blood can be topped up
- salline can keep patient alive even if ⅔of blood cells are lost
- May give patient enough time to produce new blood cells
Disadvantage of salline
- air bubbles may get in salline- dangerous
- patient may not be able to produce enough RBC so will need blood transfusion
What do plants and yeast cells produce instead of lactic acid
Ethanol (alcohol)
C02
Word equation for anaeobic respiration in plants and yeast cells
Glucose === ethanol +carbon dioxide + energy atp
- known as fermentation
Formula for anaeobic respiration in plants and yeast cells
C⁶H¹²O⁶⟶2C²H⁵OH + 2CO²+ 2ATP.
Why is fermentation of yeast of great value
Used to make bread and wine
How does fermentation help in bread and wine
-CO² from fermentation that makes bread rise
- In beer and wine making its the fermentation process that produces alcohol
What is the equation to calculate breathing rate in breaths per minute
Number of breaths= number of breaths÷ number of minutes
What are coronary arteries
Arteries that branch off aorta and supply heart with its own blood supply of Oxygenated blood
How heart responds to exercise
- breathing rate increases
-breath volume increases - to get more oxygen into blood
- heart rate increases
- to get Oxygenated blood around body faster
- removes c02 quickly
Better to have more blood cells or not
More blood cells= more oxygen can get to body cells
- high altitudes= less oxygen so people who live there produce more RBC to compensate
How to calculate rate of blood flow
Volume of blood ÷number of minutes
What is respiration needed for
-allow muscles to contract- move around
- mammals+birds= energy used to keep body temperature steady in colder surroundings
Capillaries desgined for function
One cell thick- increasing rate of diffusion by decreasing distance over which it occurs
Permeable walls
How to platelets help blood clot
- small fragments of cells- have no nucleus
-help body to clot at wound to stop all your blood pouring out and to stop microorganisms getting In - lack of platelets can cause excessive bleeding and bruising
