Lifestyle Health And Risk Flashcards
What are the 3 factors for diffusion?
-Size of organism
-Number and proximity to surface
-Activity level
Why is diffusion not used in large organisms?
-not fast enough for long distances
-won’t get enough oxygen
What’s the function of branching vessels?
Reach more places
What’s the function of unidirectional flow?
-More efficient
-keeps gradient
-stops blood mixing
What’s the function of the pressure gradient?
Faster rate of diffusion
What’s the function of the fluid medium?
Faster transportation
What happens in a single open circulatory system?
-Through heart once
-Goes to body cavity
-Organs bathe in transport fluid
What animals use this open system?
Bugs
What animals use this open system?
Bugs
What happens in a closed system?
-through heart once
-goes to fill capillaries and systemic circulation
-blood is deoxygenated throughout
What animals use this closed system?
Fish (bc they have lower activity levels)
What happens in a double closed system?
-goes to lungs before body (faster blood flow)
-blood sent low pressure to lungs to prevent tissue damage
Why is this double system used?
-can have separate pressures creating a better gradient
-no mixing of blood
-faster blood flow
Where are the bicuspid and tricuspid valves?
Bi- between LA/V
Tri- between RA/V
Where are the semilunar valves?
Between aorta/ pulmonary artery and atria
What are the adaptations of arteries
Thicker walls- cope with high BP
Small linen- maintain high BP
Collagen fibres- prevents overstretching
Elastic fibres for elastic recoil- steady BP & prevents vessel damage
Smooth endothelial layer- lowers resistance to blood flow
What are then adaptations of veins
Wider lumen- accommodates higher BV
Thinner muscular wall- less need for high BP
Valves- prevent back flow
Smooth lining of endothelial cells- reduce resistance to blood flow
What are the adaptations of capillaries
One cell thick- short diffusion distance
Branches out- large SA for diffusion
Space between cells- so WBCs can escape
No muscle- short diffusion distance
Small diameter
What are the adaptations of capillaries
One cell thick- short diffusion distance
Branches out- large SA for diffusion
Space between cells- so WBCs can escape
No muscle- short diffusion distance
Small diameter
Describe the 1st stage of the cardiac cycle
Atrial (&ventricular) diastol- blood enters atria from veins pushing on Atven
Slight higher pressure in atria then ventricles
Atven valves slightly open
SL valves closed
What’s the 2nd stage of the cardiac cycle
Atrial systole- vent muscles contract blood -> aorta
More pressure in vent then atria
Atvent valves closed
SL valves open
What’s the 3rd stage of the cardiac cycle
Vertical systole cont.- pressure difference in ventricles and arteries pushes blood into arteries
Higher pressure in ventricles
Atvent valves closed
SL valves open
What’s the final stage of the cardiac cycle
Atrial (&ventricular) diastol- vents relax drops pressure & cycle repeats
Atrial pressure= céntricas pressure
Atvent valves open slightly
SL valves closed
What’s a cohort study
2 groups of healthy people
Monitors disease development
What’s a case control study
Infected people
Common features to draw conclusions
What are the pros of cohort studies
More reliable
Large scale
What are the pros of cohort studies
More reliable
Large scale
What are the cons of cohort studies
Takes decades
Expensive
Hard to collaborate data
What are the pro of case control studies
Cheaper
Quicker
What are the cons of case control studies
High reliability on participant honesty
What’s the 1st step of atherosclerosis
Endothelium is damaged
What’s the 2nd step of atherosclerosis
Inflammatory response- WBCs and chemicals from blood (eg: cholesterol) accumulate
What’s the 3rd step of atherosclerosis
Ca salts released by collagen later forming fibrous cap (plaque)
What’s the 4th step of atherosclerosis
High blood pressure causes positive feedback loop
How is atherosclerosis a positive feedback loop
Results in high BP which increases risk for more atherosclerosis
What causes atherosclerosis?
-High BP
- toxins/ cigarette smoke
- high cholesterol/ blood sugar
What are the consequences of atherosclerosis
Build up of blood could cause aneurysm
Often fatal if bursts
Why are blood clots beneficial
-Prevent bleeding
-Stop pathogens entering
-Repair damaged tissues
How can blood clots form
-Lack of movement
-atherosclerosis bursting
- snake venom
What’s the 1st step in blood clots formation?
Platelets meet damaged endothelium
What’s the 2nd step in blood clot formation?
Platelets become sticky from contact with collagen layer and stick together- platelet plug
What’s the 3rd step in blood clot formation?
Thromboplastin released triggering Blood clotting cascade
What’s the 4th step of blood clot formation?
fibrin mesh catches RBCs forming a blood clot
What’s the blood clotting chemical cascade?
thromboplastin with Ca and vitamin k catalyse prothrombin —> thrombin
thrombin catalyses soluble fibrinogen —> insoluble fibrin
Name 3 monosaccharides
glucose, fructose, galactose
What are the properties of glucose?
Used in respiration
Soluble- easy transportation
How is fructose different to glucose?
Found in fruit- attracts animals
Sweeter than glucose
How is galactose different from these
OH H bonds are inverted compared to glucose
found in milk
What’s a glycosidic bond
Bond between monosaccharides using oxygen
Produces molecule
What’s a condensation reaction
Making new molecule
Produces water
What’s a hydrolysis reaction
Breaks molecule
Uses water
Name 3 disaccharides
sucrose, maltose, lactose
What’s sucrose made from
glucose + fructose
What’s maltose made from?
glucose + glucose
What’s lactose made from?
Glucose + galactose
Name 3 polysaccharides
Amylose, amylopectin , glycogen
What’s the structure of amylose
Only 1-4 carbon bonds
Helical
Part of starch
What’s the structure of amylopectin
1-4 and 1-6 carbon bonds
Branched (more compact that amylose)
Part of starch
What’s the structure of glycogen?
1-4 and 1-6 carbon bonds (more 1-6 than amylopectin)
More branched and compact
What are lipids made of?
fatty acids and glycerol
What are lipids?
Structural and nutrient substances (cell membrane component)
Source of vitamin A D E & K
Describe lipids solubility
Low in water
High in substances like ethanol and chloroform
What are the 3 parts of fatty acids?
Carboxylic acid group
Hydrocarbon chain
Methyl group
Describe the structure of glycerol
Hydrocarbon chain with one side of H ions and another OH ions
How are triglycerides formed?
condensation of 1 glycerol and 3 fatty acid molecules
What’s a saturated lipid?
All carbon bonds are single bonds
What are unsaturated lipids?
Has 1 or more double carbon bonds
What’s the difference between saturated and unsaturated lipids
Saturated- more dense - straighter chain
Unsaturated- less dense bent carbon chain l
What’s a phospholipid
A triglyceride where one of the fatty acids is replaced by a phosphate group
What are phospholipids used for
Make up cell membranes
What’s the phospholipid bilayer
Phosphate end = soluble in water
Fatty acids orientate away from water (water = polar)
Define metabolism
Sum of all chemical reactions in cells
Define metabolic rate
Speed of which the reactions occur
What is blood pressure?
Max pressure generated in ventricle/ min pressure when ventricles relax
Systolic pressure: diastolic pressure
What is blood pressure effected by
Blood volume
Cardiac output
Blood vessels’ peripheral resistance
What is peripheral resistance
Resistance due to friction between blood and vessel wall
What are factors of high blood pressure
Chronic stress
Age
High salt diet
How does chronic stress impact high blood pressure
releases hormones which constrict arteries
(smaller lumen for same blood volume)
How does age impact high blood pressure
reduces artery elasticity (can’t stretch as much)
How does high salt diet affect high blood pressure
kidneys retain more water increasing blood volume
What are three types of medication for CVD
Antihypertensives
Cholesterol lowering
Anticoagulants and platelet inhibitors
What’s an example of antihypertensive
calcium channel blockers, ACE inhibitors
What’s an example of cholesterol lowering drugs
Statins
What’s an example of anticoagulants and platelet inhibitors
Aspirin
What do anti hypertensives do
Reduce blood pressure
what are the side effects of antihypertensives
nausea and dizziness
What do cholesterol lowing drugs do
Inhibits enzyme that makes LDL cholesterol
What are the side effects of cholesterol lowering drugs
nausea
Muscle pain/ cramps
liver damage
What do anticoagulants and platelet inhibitors do?
Reduce risk of blood clots
What are the side effects of anticoagulants and platelet inhibitors
Nausea, uncontrolled bleeding, stomach ulcers
What is the role of cholesterol?
Stabilises fluidity if cell membranes
Makes up sex hormones
How is cholesterol transported?
as a lipoprotein due to being insoluble in water
How is cholesterol transported?
as a lipoprotein due to being insoluble in water
What are LDLs
low density lipoproteins
from saturated fats
What are LDLs
low density lipoproteins
from saturated fats
What are HDLs?
high density lipoproteins
from unsaturated fats
What do LDLs do?
bind to cell membrane receptors before entering cells
Carries cholesterol from liver to cells
What do HDLs do?
transports cholesterol to liver for breakdown
What should the ratio of LDLs and HDLs be?
Low LDLs
High HDLs
Why should the ratio of LDLs be this way
Excess LDLs increases blood cholesterol (due to blocking cell membrane receptors) risk of atheromas
Why should the ratio of HDLs be this way?
HDLs lower blood cholesterol and removes/ reduced fatty plaques from atherosclerosis
