3. How do organisms sustain themselves Flashcards
What happens during inhalation?
1) Intercostal muscles and diaphragm contracts and moves down
2) Volume of thorax increases, which decreases the pressure.
What happens during exhalation?
Intercostal muscles relax, moving the ribs down and in
The diaphragm relaxes and moves up (into a dome shape)
The volume of the thorax decreases, and so the pressure increases, thus, air is released.
Explain large surface area of lungs adaptation
Lungs have alveoli which have a lot of surface area due to their shape which aid in gas exchange to occur between the respiratory surface and the bloodstream.
What is ventilation?
It ensures there is always a difference in the oxygen concentration between the alveoli and the blood.
Explain concentration gradient in respiration adaptation
Oxygen moves from alveoli to blood stream where particle pressure is lower and carbon dioxide moves from blood to alveoli where particle pressure is higher.
Explain small diffusion distance in respiration adaptation
There is very less space between the walls of alveoli and capillaries surrounding them, which allows for faster rate of diffusion. This thin barrier ensures rapid and efficient exchange of gases.
What is the function of carbohydrates (sugars)?
For energy
What is the function of proteins?
Help your body repair cells and create new ones
What is the function of fats/ lipids?
Store energy, insulation
What is the function of Iron?
To make hemoglobin in blood
What is hemoglobin?
Facilitates the transport of oxygen in red blood cell
What is the function of Calcium?
To make bone
What is the function of vitamins?
Chemicals that ensure cells function properly
What is the function of fibre?
Helps transit of food through the gut (soluble fibre lowers cholesterol)
Macromolecule of carbohydrate
Starch
Macromolecule of proteins
Amino Acids
Test for carbohydrates/ stach
Put substance in beaker, add few drops of iodine, if substance turns blue/black there is starch in the solution
Macromolecule of lipids
Fatty Acids/ Glycerol
Test for glucose
Heat the beaker containing the substance and add blue benedicts reagent. If the substance turns orange/brown that means glucose is present.
Test for protein
Add NaOH and CuSO4 to the solution in the beaker, if colour becomes purple protein is present.
Biruret
Test for lipids
A small quantity of alcohol is added to the test solution - the mixture is shaken vigorously. A milky-white emulsion is formed if fats are present.
What is the function of liver?
Produces bile
What is the function of gal bladder?
Stores bile
What is the function of stomach?
Stores and churns food, HCl activates enzymes and kills germs
What is the function of pancreas?
Secretes insulin and glucagon hormones and makes pancreatic juices which regulate blood sugar levels. Bicarbonates are released to neutralise stomach acid.
What is the function of large interstine?
Reabsorbs water and ions, forms and stores faeces.
What is the function of small interstine?
Completes digestion, absorbs nutrients
What digests lipids in small interstine?
Lipases
What digests starch to maltose?
Amylase
What is the function of bile?
1) Emulsification of fat globules
2) Makes the pH of interstine to Alkaline since digestion of carbohydrates and proteins happens in an alkaline medium
Maltose digests what to glucose?
Starch
What are the four steps of digestion?
- Ingestion
- Digestion
- Absorption
- Elimination
What is the pathway of food called?
Alimentary Canal
Mouth- Esophagus- Stomach- Small Interstine- Large Interstine- Anus
What are arteries?
Carry oxygen rich blood away from the heart
What are veins?
Blood vessels that carry blood back to the heart
What is the function of capillaries?
Site of exchange between blood and tissues
How are arteries adapted to their function?
- They have thick layers of muscle to make them strong enough to withstand the high pressure at which they carry blood
- They have strong elastic fibres to allow them to stretch and spring back
How are capillaries adapted to their function?
- They have permeable walls so that substances can diffuse in and out
- Their walls are only one cells thick which increases the rate of diffusion by decreasing the distance over which it occurs
How are veins adapted to their function?
- The walls are not thick as blood is not carried at a low pressure
- They have a big lumen to help blood flow
- They have valves to keep blood flowing in the right direction
Anatomy of the heart
TBC
Positive feedback loops
Allows your body to control its internal environment by responding with a increase in function
Order of events of heart pumping blood (8 steps)
- Superior and inferior vena cava bring in dexoygenated blood from the body
- Goes into right atrium
- Through the tricuspid valve goes into right ventricle
- Through the pulmonary valve goes into pulmonary artery
- Goes into the lungs ( gets oxygenated)
- Goes into Left atrium
- Left ventricle pumps the blood into the Aorta
- Goes into the rest of the body
Negative feedback loops
Allows your body to control its internal environment by responding with a decrease in function
