P1- Organisation Flashcards
Give examples of some organ systems
Respiratory, digestive, nervous, circulatory, reproductive, excretory
What is the order of the principles in organisation?
Cell, Tissue, Organ, Organ system, Organism
What is the function of the digestive system?
To break down food by mechanical and enzyme action
Define mechanical digestion
Physically (grinding by teeth) making food into smaller pieces
Define egestion
Removal of food from the body that cannot be digested
Define excretion
Separation and removal of metabolic waste from the body (e.g urea, carbon dioxide)
Define ingestion
Taking food into the alimentary canal (eating)
Define digestion
The process of breaking down food by mechanical and enzyme action
What is the mouth’s role in digestion?
Teeth= Chew/grind food (mechanical digestion)
Saliva= Contain amylase enzyme to break down big carbohydrate molecules (chemical digestion)
What is the oesophagus’ role in digestion?
Long tube carrying food from throat to stomach
What is the stomach’s role in digestion?
Churns food and mixes it by contracting muscles walls (mechanical digestion) and containing hydrochloride acid which kills bacteria that may be in the food we eat
What is the small intestine’s (microvilli) role in digestion?
-Absorb digested food molecules through walls into blood
-Villi increases surface area for greater rate of diffusion
-Thin walls for shorter diffusion pathway
-Large capillary network to maintain concentration gradient
What is the function of bile in the small intestine?
Neutralise small amounts of acid still on food from stomach and emulsify fats so they can be mixed with water
What is the large intestine’s role in digestion?
Receive water and water after absorption of useful molecules in small intestine. Water absorbed back into body, waste left goes to rectum where it’s stored ready to be removed from anus
What is the liver and pancreas’ role in digestion?
Pancreas releases enzymes which are required for small intestine. Liver filters poisons and toxins from the blood and stores glucose
What does amylase break down and where is it found?
Starch to simple sugars, salivary glands, pancreas and small intestine
What does lipase break down and where is it found?
Lipids(fats) into fatty acids and glycerol, pancreas and small intestine
What does protease break down and where is it found?
Large proteins into amino acids, stomach, pancreas and small intestine
Define enzymes
Biological catalysts that speed up the rate of (metabolic) reactions
Explain lock and key theory
Enzymes function like locks while substrate (the thing getting broken down) is the key. Each enzyme is a specific shape and will only act on one particular type of substrate. Substrate can fit into active site of enzyme. Products are released from active sit of enzyme and enzyme is ready to be reused
Explain food test for starch
Use iodine solution, positive test goes black or blue
Explain food test for lipids
Use alcohol (water after) and filter paper, positive test goes cloudy
Explain food test for protein
Use biuret reagent, positive test goes purple
Explain food test for sugars
Use benedict’s reagent, if positive it goes orange/brick red
Define active site
Site on enzyme surface where substrate fits
Define activation energy
The minimum amount of energy needed for a collision between two particles to result in a reaction
What factors affect enzyme action?
Temperature and pH
What is the maximum/optimum pH for enzyme activity?
8
Define optimum temperature
The temperature at which the enzyme is working at the fastest rate possible
Optimum temperature = most collisions
What happens when the pH reaches 9 and above?
It becomes denatured and the rate of enzyme activity decreases
What is the function of the heart?
The muscular organ that pumps blood around the body and is part of the circulatory system
What is the function of the pulmonary artery?
Carries deoxygenated blood to the lungs
What is the function of the vena cava?
Brings deoxygenated blood from the body
What is the function of the pulmonary vein?
Brings oxygenated blood from the lungs
What is the function of the aorta?
Carries oxygenated blood to the body
Acronym for pulmonary artery and vein?
A rtery- A way from heart
veIN- IN to the heart
What is the role of the valves?
Stop blood flowing backwards
How is the heart a double pump?
1st pump- Blood is pumped to the lungs and returns to the heart
2nd pump- Blood is pumped to respiring muscles and back to heart again which means that the blood enters the heart twice for every cycle
What are the roles of the coronary arteries?
Deliver oxygen to the heart’s own muscles, blockage causes them to become constricted which reduces blood flow and can cause a heart attack
How is the alveoli adapted in the lungs?
One cell thick/thin walls, large surface area, moist and permeable walls (allowing gases to pass through), extensive blood supply, large diffusion gradient
Why does the left ventricle have a thicker wall than the right ventricle?
It pumps the high pressure blood around the whole body
What is the function of the red blood cells?
Have haemoglobin which helps transport oxygen around the body
What are the components of blood?
Red blood cells, white blood cells, platelets and plasma
What are the adaptations of the red blood cells?
Biconcave disc and no nucleas, meaning a large surface area to volume ratio
What percentage composition of the blood do red blood cells make up?
45%
What is the function of the white blood cells?
Engulf and destroy pathogens, produce antibodies to fight infection, produce antitoxins to neutralise toxins produced by bacteria
What are the adaptations of the white blood cells?
Have a nucleas, have an irregular shape which can change to engulf pathogens
What percentage composition of the blood do white blood cells make up?
<1%
What is the function of plasma?
Transports water products (urea and carbon dioxide), hormones, antibodies and nutrients
What is the adaptation of plasma?
Pale, yellow coloured liquid everything else is suspended in
What percentage composition of the blood does plasma make?
55%
What is the function of the platelets?
Helps blood to clot at a wound
What is the adaptation of the platelets?
Small fragments of cells, no nucleas, change shape
What percentage composition of the blood do platelets make?
<1%
What is blood?
A tissue made up of specialised cells
Explain the characteristics of an artery
Thick walls, small lumen, thick layer of muscles and elastic fibres, no valves, under higher pressure (blood) than veins, carry blood away from the heart
Explain the characteristics of a vein
Relatively thin walls, large lumen, often have valves, transport blood to heart, lower pressure
Explain the characteristics of a capillary
Walls are a single cell thick, tiny vessel with narrow lumen, permeable, forms network connecting arteries and veins
How do you calculate the rate of blood flow?
Volume of blood in artery divided by the number of minutes
If the coronary arteries narrow or become blocked- build up of plaque, what can happen?
A thrombosis which is the clotting of blood in a blood vessel and could cause a heart attack
What happens in a coronary heart disease?
Layers of fatty material build up inside coronary arteries, narrowing them. This reduces flow of blood through coronary arteries resulting in a lack of oxygen for heart muscles
What two things can be done to treat a cardiovascular disease?
Statins or stents
Explain what a stent is
A stent is a wire mesh tube or balloon to widen the artery allowing blood flow to increase. This results in more oxygen supplied and removal of carbon dioxide
Disadvantages of stents
A risk of infection from the surgery, complications
Advantages of stents
Usually effective, no medicine/ everyday expenditure
Explain what statins are
Drugs that are used to reduce blood cholesterol level to slow done the rate of fatty material deposit in the coronary arteries
Disadvantages of statins
Could be allergic, could be side effects (liver/kidney damage), easily forget to take, not instantly effective, don’t dissolve the existing plaque
Advantages of statins
No surgery or risk of infection, simple task to take medicine
What happens if you have faulty heart valves?
They can be replaced with either biological or mechanical valves
What do artificial valves do?
Mimic the heart valves, made of materials like plastic that don’t corrode
Why might a patient choose a mechanical valve over a biological valve?
No need for another replacements after 5 years but biological you would, durable, doesn’t break, no ethical issues, no risk of injection
Why might a patient choose a biological valve over a mechanical valve?
There is no risk of blood clotting around the valve but mechanical can cause blood to clot
What is the role of an artificial pacemaker?
Electrical devices used to correct irregularities in the heart rate. Implanted under the skin with a wire which connects it through a vein to the right atrium
Advantages of artificial pacemakers
Fixes irregular heartbeat, works automatically
Disadvantages of artificial pacemakers
Requires operation, must be replaced every 10 years, a donor must be found that matches
Define non communicable diseases
Not transferred between people or other organisms and not infectious. Affect people due to genetics, lifestyle and factors in their environment not pathogens
Define health
A state of complete physical, mental and social wellbeing
Define disease
A disorder that affects an organism’s body, organ, tissues or cells
Define risk factor
Something that contributes to increased chances of diseases developing
What can diet, smoking and expertise lead to?
Cardiovascular disease
What can obesity lead to?
Type 2 diabetes
What can carcinogens lead to?
Cancer
What can smoking lead to?
Lung disease/cancer
What can an alcohol addiction lead to?
Liver and brain function problems
What is cancer?
Changes in cells that leads to uncontrollable growth and division. A group of cancerous cells produces a growth called a tumour
Define benign
Non cancerous tumour cells that grow only locally and cannot spread by invasion or metastasis
Define malignant
Cancerous cells invade neighbouring tissues e enter blood vessels and metastatasize to different sites
Define carcinogens
A substance, organism or agent capable of causing cancer
Give examples of carcinogens
Tanning beds, cigarette smoke, x-rays, coming into contact with ionising radiation, UV rays and certain viruses
What are treatments of cancer?
Radiotherapy and chemotherapy
What is radiotherapy?
Using radiation to kill cancerous cells
What is chemotherapy?
Using chemicals to kill cancerous cells
What are human costs of Non communicable diseases?
Lower quality of life, shorter lifespan, families of sufferer affected
What are financial costs of Non- communicable disease?
Cost of healthcare, research into disease reduced due to inability to work, personal care costs
What are two examples of Chronic Obstructive Pulmonary disease (COPD)?
Bronchitis and Emphysema
What is bronchitis?
The bronchi and bronchioles are inflamed are excess mucus is produced
What is emphysema?
Affects the alveoli; walls are broken down and then they trap excess air
What are short term effects of alcohol on the brain?
Slows reaction time, difficulty walking, impair memory, slurred speech, change in sleep patterns and mood
What are long term effects of alcohol on the brain?
Brain shrinkage, memory problems, physchiatric problems
What is the function of the xylem and phloem?
Transport tissues in plants
What are the functions of the xylem tissue?
Carries water and dissolved minerals from roots to leaves by a process called transpiration, physical or passive process, walls thickened with lignin, composed of hollow tubes providing strength and support to plant, direction is UP
What are the functions of the phloem tissue?
Carries dissolved foods (sugars)- cell sap from the leaves around the plant by a process called translocation, requires energy (active process), composed of tubes of elongated cells (sieve and companion cells), direction is UP and DOWN
Explain what meristems are
Unspecialised stem cells in plants, meristem tissue can differentiate into any tissue plant needs, found at shoot and roots of plant
What are stomata and guard cells?
Control gas exchange and water loss
What happens when stoma is open and when it is closed?
Open- increased turgor pressure
Closed- decreased turgor pressure
What are the roots of a plant?
Thick, divided tubes with large surface area, adapted to take water and mineral ions from the soil. Root hair cells on the root tip are tiny projections and increase surface acrea
How does water get into a plant?
Absorbed from soil through root hairs, transported up the stem to the leaves, evaporated through the leaves (transpiration)
What is transpiration?
Evaporation of water from the leaves or aerial parts of a plant
What is a transpiration stream?
Continuous movement of water through the xylem from the roots to the leaves
What does transpiration provide plants with water for?
Cooling, photosynthesis, support (turgor pressure and prevents wilting), movement of minerals
What factors affect transpiration?
Light, temperature, humidity, wind
How does light affect transpiration?
More light= Increased transpiration, photosynthesis increases, stomata opens to allow more CO2 into leaf and water to exit
How does temperature affect transpiration?
Higher temperature= Increased transpiration, evaporation and diffusion are faster at higher temperatures
How does humidity affect the rate of transpiration?
Higher humidity= decrease transpiration
How does the wind affect the rate of transpiration?
Windy conditions= increased transpiration, water vapour is removed quickly by air movement, speeding up diffusion of more water vapour out of the leaf
What is translocation?
The movement of sugar produced in photosynthesis to all other parts of the plant for respiration, occurring in phloem cells
Explain sieve cells
Specialised for transport and have no nuclei. Each has a perforated end so it’s cytoplasm connects one cell to the next
Explain companion cells
Transport of substances in the phloem requires energy. One or more of these cells attached to each sieve tube provide thus energy
