bio Flashcards
Explain why blood pressure must decrease in the arterioles
before entering the capillaries
-to prevent damage, allow efficient exchange, and regulate blood flow. -they have thin walls, that could rupture under high pressure
-lower pressure slows blood flow, maximizing time for oxygen and nutrient exchange.
Why is there less blood flow when your leg is still?
- Muscle contractions help push blood back towards the heart
-when the leg is still, muscles dont contract, so this process doesn’t happen (lack of movement). - this reduces venous return (amount of blood returning to the heart).
-without muscle movement, blood flow slows down.
How do phagocytes defend the body?
- by engulfing, destroying pathogens through phagocytosis
-they detect, surround, and ingest pathogens, then use enzymes to break them down and eliminate them
-helps prevent infections from spreading
-are an important part of the immune system’s first line of defense.
Explain how the structure of an artery is related to its function?
- they have thick, muscular walls to withstand high blood pressure and maintain blood flow
-their elastic fibers allow them to stretch and push blood forward - a narrow lumen keeps pressure high so theres efficient transport of blood from the heart to the body
CORMS QUESTION: to investigate the effect of exercise on heart rate
- IV: level of exercise performed (walking, jogging, sprinting), also amount of time.
- human participants (similar age, gender, fitness level) reduce extraneous variables affecting heart rate.
- repeat for each exercise level 3 times per pers to calculate average heart rate and ensure reliability.
m1: heart rate (DV), measured in bpm using a heart rate monitor.
m2: time scale for measuring heart rate will be before, after exercise (immediately after and then at intervals for 5 mins after).
-keep the same: duration and intensity of the exercise.
First Image: Oil and Water Investigation
Bile → A. Bile and Lipase → C. Boiled Lipase → B Bile and Protease → A
diagram
I) X is the right side of the heart because it is connected to the pulmonary artery, which carries deoxygenated blood to the lungs while the left side pumps oxygenated blood to the rest of the body.
ii) left ventricle
iiv) chamber a (left ventricle) has a thicker wall because it pumps blood to the whole body, requiring more force.
Chamber B (Right Ventricle) has a thinner wall because it pumps blood to the lungs, requiring less force.
vitamins
vitamin A: beneficial for eye especially the retina
vitamin c: helps the cells stick together, prevents wounds
iron: part of haemoglobin, carry oxygen
dietary fibre: prevents constipation, helps peristalsis
describe a test to show that a meal contains glucose
-in a sample of a food, add Benedicts solution and place it in a water bath that is boiling.
-the color will change from blue to orange
three chemical elements found in lipids and also found in proteins
carbon, hydrogen, oxygen
emulsion test (fat)
- add 2-3 cm³ of ethanol with the food sample.
- gently shake the test tube to dissolve any fat.
-add an equal amount of water and shake again.
Milky or cloudy (fat present).
Clear solution (no fat present).
test for lactose or sugar
- add 2-3 cm³ of benedicts solution to the food solution.
-place the test tube in a boiling water bath for 3-5 minutes.
Color change from blue to green, yellow, orange, or brick-red (lactose present).
No color change, stays blue (no lactose).
