Chapter 6 Application Flashcards
1
Q
Harvey showed that:
A
- Blood flow is unidirectional
- Valves prevent backflow
- Blood is NOT consumed in body
- Arteries pump blood out, veins in
- Predicted presence of fine vessels that linked arteries to veins
2
Q
Dialysis Tubing
A
- models absorption by the epithelium of the intestine
- distilled water used
- cola drink contains mix of substances used to model digested + undigested food in intestine
- water outside bag is tested to see if substances in the cola have diffused through dialysis tubing
- glucose & phosphoric acid should diffuse through the tubing but caramel which has larger polymers of sugar should not
3
Q
Coronary arteries
A
- provide the heart muscle tissue w/ oxygen & nutrients
- branch from aorta
4
Q
Coronary thrombosis (Occlusion)
A
formation of a clot that occludes coronary artery & causes heart attack
- coronary arteries blocked w/ calcified fatty substance called plaque
- if deposits of plaque in coronary arteries rupture, blood clots form
- plaque is composed of fatty acids + cholesterol
- artery wall begins to occlude
- reduces width of lumen of artery
- surface of arterial wall = roughened
- causes platelets to break, initiating formation of clot called thrombosis
- leads to heart attack (uncoordinated contraction called fibrillation)
5
Q
Atherosclerosis
A
- hardening of arterial blood vessels
- artery wall thickens / formation of plaque within arteries
- accumulation of fatty materials like cholesterol, triglycerides, some calcium
- reduces elasticity of artery walls
- increases blood pressure
- inflammatory response in walls of arteries caused by accumulation of macrophages & white blood cells
6
Q
Causes of coronary artery disease
A
- high blood cholesterol levels
- smoking
- high blood pressure
- high blood sugar levels, usually due to diabetes
- genetic factors
7
Q
Florey & Chain + Penicillin testing
A
- their first test was on 8 mice infected with a bacterium that causes a fatal pneumonia
- all 4 treated mice recovered, but untreated mice died
- tested on man close to death
- began to recover but supplies ran out
he died
8
Q
Causes of emphysema
A
- emphysema is a chronic disease of the lungs where the alveoli of the lungs are damaged & enlarged, causing breathlessness
- cilia that line the airways & expel mucus are damaged & cease to function
- mucus builds up in lungs & causes infections
- toxins in cigarette smoke & polluted air cause inflammation & damage to white blood cells that fight infections in lungs
- a protease (trypsin) is released from inflamed cell & damaged white blood cells
- this enzyme digests elastic fibers in the lungs & eventually causes complete breakdown of alveolus walls
9
Q
Consequences of emphysema
A
- SA for gas exchange reduces so oxygen saturation of blood falls and exercise is more difficult
- lungs lose their elasticity, making it difficult to exhale (Shortness of breath)
- mucus in lungs causes coughing and wheezing
10
Q
Causes of lung cancer
A
- smoking –> tobacco contains mutagens
- passive smoking –> passing on carcinogens
- air pollution –> diesel exhaust fumes, nitrogen oxides from vehicles, smoke
- radon gas –> leaks out of rocks esp. granite
- asbestos & silica –> dust from these materials causes cancer if deposited on lungs
11
Q
Consequences of lung cancer
A
- difficulties breathing
- persistent coughing
- coughing up blood
- general fatigue
- chest pain
- loss of appetite
- weight loss
12
Q
Harvey & Sexual Reproduction
A
- was taught the “seed & soil” theory of Artistotle
- male produces a seed, which forms an egg when it mixes w/ menstrual blood - the egg develops into a fetus inside the mother
- tested this theory using a natural experiment
- deer only become sexually active during the autumn
- examined the uterus of female deer during mating season by slaughtering & dissecting them
- expected to find eggs developing in the uterus immediately after mating (copulation) but only found signs of something developing in females 2 or 3 months after start of mating season
- thought this falsified Artistotle’s theory
- he concluded that offspring CANNOT be the result of mating - which was false
- the issue was that he didnt have the technology (microscopes) to see gametes
13
Q
Cholinergic synapses
A
- synapses that use ACh are called cholineric synpases
- pre-synaptic neuron secretes ACh into synaptic cleft
- diffuses across synapse
- binds to receptors in post-synaptic membrane
- ACh broken down in synaptic cleft
- by enzyme cholinesterase
- produces acetyl groups and choline
- choline reabsorbed by pre-synaptic neuron
14
Q
Neonicotinoid pesticides
A
- bind to ACh receptors in post-synaptic membranes of cholinergic synapses in insects
- cholinesterase does not break down these pesticides so they remain bound to receptors
- prevents ACh from binding (inhibitor)
- block synaptic transmission, killing insect
sadly honey bees are also killed :(
15
Q
Jet lag
A
- experienced when travelling rapidly b/w time zones
- caused by SCN & pineal gland continuing to set a circadian rhythm to suit the timing of day & night at point of departure
- time impulses sent by ganglion cells to SCN when they detect light helps to adjust to new regime
- melatonin pills can be taken
