Flashcards in Principles Of Organisation Deck (108):
The building blocks of living things eg stem cell
A group of cells with similar structure and function eg muscle
Groups of different tissues working together eg heart
Groups of organs that perform a particular function eg circulatory system
A whole living thing eg a plant or an animal
What do large multicellular organisms develop?
Systems for exchanging materials
Big multicellular systems eg animals like mammals have several different organ systems for absorbing eg gut transporting eg blood system and exchanging materials eg lungs
What happens during the development of a multicellular organism?
The cells differentiate so that they can perform different functions
Specialised cells form tissues & 1 or more types of tissues are structured to form organs and two or more organs can work together in an organ system
What is a tissue?
Group of specialised cells with similar structure and carry out a particular function
Contract to bring about movement eg contraction and relaxation to move limbs
Produce and secrete substances such as enzymes to enable chemical reactions and hormones to control certain functional features of an organism
Covers some parts of the body including the inside of the gut and the skin
What are organs?
Different tissues acting together to perform some particular function
Muscular tissue in stomach?
Churn contents and break up the food into smaller chunks to aid digestion
Glandular tissue stomach?
Produce digestive juices containing enzymes to break food down at the molecular level
Epithelial tissue stomach?
Covers outside and inside of the stomach
What are organ systems?
Groups of organs that work together to perform a particular function
An epithelial cell size?
30 to 60 micrometers
0.5 - 1.6mm
Small intestine size?
6m or 20ft
Smooth muscle tissue stomach?
Contracts to churn food
Glandular tissue stomach organ?
Produced acids & enzymes
Nervous tissue stomach?
Controls activities in the stomach
Tissue made up of plasma, RBC, WBC, platelets etc
Goblet cells secrete mucus
protects stomach lining
Exchange of material is made easier by?
Increased surface area
Good blood supply and flow
Increased concentration gradient
SA TO V RATIO?
volume = side length3
surface area = 6x(side length)2
SA:V = (surface area/volume) : 1
Increasing the size...
Decreases the SA to v ratio
Why do large organisms need a transport system?
- the SA isn't big enough to supply needs of body
-mammals are large so need mass transport system to supply feels with materials
-specialised exchange surfaces are needed to absorb nutrients, respiratory gases and remove excretory products
-transport system needed to transport materials between exchange surfaces and cells
-the more active & bigger organism, the more need for a specialised transport system with pump
What are substances transported in and out of organisms?
O2, CO2, water, dissolved food molecules, mineral ions and urea
How are dissolved materials transported around the body?
small, red, disc shaped (biconcave disc)
slightly bigger, loped nucleus
has a large nucleus
straw coloured liquid
Components of blood?
minerals (iron, calcium)
urea (waste product formed in liver from breakdown of proteins)
fatty acids & glycerol
last 4 products of digestion
What are platelets?
Fragments involved in the clotting of blood
Amount of RBC?
5 million in 1mm3
Function of RBC?
pick up oxygen from lungs and carry to tissues and cells where needed
Adaptions of RBC?
biconcave discs (pushed in at both sided) give increased SA to V ratio over which oxygen can diffuse
contain pigment called haemoglobin (red) which can carry oxygen
no nucleus so more space to pack in molecules of haemoglobin
What is haemoglobin?
Large protein molecule folded around 4 iron atoms(purply/red the colour of blood in veins)
Formation of oxyhaemoglobin?
In high concentration of oxygen the haemoglobin reacts with oxygen to form it (scarlet in colour causing blood in most arteries to be bright red)
Reverse of oxyhaemoglobin?
In areas of low oxygen concentration the reaction reverses and it splits back to oxygen and haemoglobin & the oxygen diffuses to cells where it's needed
What happens if your diet lacks iron?
Not enough red blood cells are produced and you become anaemia
carry blood away from heart
bright red (oxygenated)
high pressure & no valves
small lumen, thick layer of muscle & elastic fibres, thick walls
carry blood toward the heart
deep purply-red (deoxygenated)
low pressure & valves to prevent back flow of blood
large lumen, thin walls & often have valves
blood flows through them, allows exchange of substances & connects veins to arteries
bright red (artery) to purply red (veins)
v low pressure & no valves
walls 1 cell thick
tiny vessel with narrow lumen
In the capillaries what happens?
Body cells are bathed in tissue fluid, dissolved food eg glucose, amino acids, fatty acids and glycerol, o2 and co2 and exchanged
What happens to blood coming from the heart?
Flows through arteries and branches into the smaller arterial and eventually into capillaries, which are thing walls so exchange of body cells and the blood of substances takes place here
How are waste products removed?
Travel via venules which join to form veins which return blood to heart
Made of cardiac muscle
pumps blood around the body beat 70 x per minute
coronary arteries supply heart with oxygen and glucose for respiration which releases energy for contraction of the heart
What does blood flowing towards the heart do to valves in veins?
Passes easily through the valves
What does blood flowing away from the heart dies to valves in veins?
Pushes valves closed and so blood is prevented from flowing any further in this direction
What does the pulmonary artery do?
Takes deoxygenated blood to lungs
What does the aorta do?
Carries oxygenated blood around the body
What is the trip of blood?
Semi lunar valve
All around the body
What is the double circulatory system?
Important in warm blooded animals
The right ventricle pumps blood to the lungs where gas exchange takes place, this causes a drop in blood pressure so it is returned to the heart, fully oxygenated and the left ventricle then pumps it with a greater force to difference parts of the body
More areas of the body receive fully oxygenated blood quickly
The natural resting heart rate is controlled by a group of cells located in the wall of the right atrium that act as a pacemaker. Artificial pacemakers are electrical devices used to correct irregularities in the heart rate.
The cardiac cycle?
- the heart beat begins when the heart muscles relax and blood flows into the atria
-the atria then contract and the valves open to allow blood into the ventricles
-the ventricles contract forcing the blood to leave the heart through the arteries. At the same time, the atria are relaxing and once again filling with blood
-the cycle then repeats
What are the coronary arteries?
The coronary arteries branch over the wall of the heart from the outside and supply the heart muscle itself with oxygen and glucose, there are normally 4 or 5 branches
What is CHD?
When layers of fatty material build up inside the coronary arteries, narrowing them
Order of organisation?
Consequences of CHD?
Reduces blood or no blood flow to area of heart muscle, the heart may beat out of rhythm and it may cause a heart attack or a cardiac arrest
Treatment of CHD?
CABG, blood vessels are seen into the coronary artery to bypass blockage. A balloon can be inserted to open up the blockage and stents are metal mesh tubes that may be places in the artery and inserted with a tiny balloon to push open the artery.
What are faulty valves?
When valves might not open fully or the heart valve might develop a leak
What are consequences of faulty valves?
Person affected can become breathless of in severe cases die if problem is not solved
Treatment of faulty valves?
They can be replaced. Mechanical valves last a long time but you have to take mediation to prevent blood clotting. Biological valves are from animals such as pigs or cattle and last without medication but only for around 15 years. Also people may be ethically or religiously against use of animals.
For donar heart you have to wait for tissue match and artificial hearts can be used to keep patients alive whilst waiting for a donar or as an aid to recovery
Pros and cons of artificial heart?
-keep patient alive
-no waiting for donar
-live relatively normal life
-drugs needed to prevent
-noisy & heavy
Pros and cons of transplant?
-need anti reaction medicine
-body may reject
Reduce blood cholesterol levels which slow down rate of fatty material deposit, reduces risk of CHD
Reducing risks of CHD?
healthy & balanced die
physically active & regular excessive
take correct medication
keep blood pressure & diabetes controlled
Nose and mouth
air sack (walls are 2 cell thick)
Factors affecting rate of diffusion?
Thickness of diffusion pathway
What are the lungs two main functions?
Mechanical ventilation (breathing)
When we inhale?
Muscle in ribs contract
Ribs move up and out
Diaphragm contracts and flattens
Volume increases, pressure decreases
Air rushes in to equalise pressure
When we exhale?
Muscles in ribs relax
Ribs move down and in
Diaphragm domes and relaxes
Decreases volume, increases pressure
Air is forced out of lungs
The lungs are efficient because?
Folded so larger surface area
Walls of alveoli 1 cell thick - shortens diffusion distance
Alveolus surrounded by blood capillaries so there is good blood supply and blood is constantly taking oxygen away and adding co2 which helps maintain a maximum concentration gradient between blood & air in alveoli
Alveolus is ventilated, removing waste carbon dioxide and replenishing oxygen levels to help maintain maximum concentration gradient between the blood and air in the alveoli
Muscular wall churns food. Produced HCl (kills bacteria) and provides optimum conditions for pepsin (protease enzyme)
Produces trypsin (protease enzyme) carbohydrase and lipase enzymes
Faeces stored here
Produced carbohydrase, protease, lipase enzymes. Walls have villi and microvilli to increase SA for absorption. Absorption of soluble food occurs.
Water reabsorbed from undigested food, producing faeces
long, muscular tube that squeezes good down to the stomach (peristalsis)
Secrete the digestive juice amylase (a carbohydrase)
What are enzymes?
Enzymes are biological catalysts and they speed up the rate of a chemical reaction but are not used up and they are proteins. Long chains of amino acids are folded to produce a molecule with a specific shape
What does this specific shape allow?
It allows other molecules (substrates) to fit into the enzyme protein. We call this the active site. This means the shape of the enzyme is vital for how it works
Enzymes are involved in...
Building large molecules from lots of small ones
Changing one molecule info another
Breaking down large molecules into smaller ones o
What is the enzyme reaction equation?
Substrates --------> product(s)
How do enzymes work?
Substrate (reactant) fits into shape of the enzyme like lock and key and they bind together (enzyme-substrate complex). Reaction take place rapidly and products are released and the substrate splits into products and leave the active site.
Why do enzymes work best under specific conditions of temperature and pH?
Because anything which affects the shape of the active site also affects the ability of the enzyme to speed up a reaction
The special site in the structure of an enzyme where the substrate binds
The energy needed for a chemical reaction to take place
A biological catalyst
A substance which changes the rate of a chemical reaction without being changed itself
Go to sugar via carbohydrase
eg amylase found in saliva breaks down starch to glucose
To amino acids via protease
eg pepsin in the stomach, breaks down protein to amino acids
To fatty acids and glycerol via lipase
Lipase pH decrease?
lipase digests fat to produce fatty ACIDS
Enzymes best temp?
What happens in body?
lipase likes alkali (small intestine)
stomach is acidic (HCL acid)
bile squirted (alkali)