Diffusion/Osmosis
Define osmosis
The movement of water across a membrane
Most homeostatic mechanisms in the body are what type of feedback loop?
Negative feedback loop
The presynaptic neuron
Cardiac Output = ? x ?
CO = HR x SV
Define antagonist
A substance that blocks the action or effects of another substance
Define osmolarity
The number of solute particles within a water solution
TRH stimulates TSH secretion, and TSH stimulates TH release; this is a negative feedback loop. Therefor, decreased TH would have what effect on TRH and TSH?
TRH and TSH would increase
What would be the effect of a neurotransmitter agonist?
An agonist would increase neurotransmitter production
Blood Pressure = ? x ?
BP = CO x Resistance
What does a sloping line on a graph indicate about the X- and Y- variables?
The X-variable affects the Y-variable
A hypotonic solution would have what effect on a cell?
Increased osmolarity stimulates increased ADH production (causes water retention) and inhibits Aldosterone secretion (promotes sodium retention), which decreases osmolarity as part of a negative feedback loop. Therefore, what would be the effect of decreased osmolarity on ADH and Aldosterone?
Decreased ADH and
increased Aldosterone
How are excess neurotransmitters removed from the synapse?
Diffuse away, reuptake by presynaptic cell, broken down by enzymes
A decrease in pH (high H+) would have what effect on respiration?
Hyperventilation
The cerebellum uses visual, vestibular, & proprioceptive info to maintain balance. It can do so with just two of these sense, but not only one. A positive Romberg sign is swaying upon closing the eyes. An individual has a positive Romberg sign and feels like the world is spinning, even with their eyes open. What is the most likely cause?
A vestibular deficit
In fresh water, skin will become "wrinkled" due to osmosis. Does water move in or out of the skin to cause this effect?
Water moves into the skin, increasing the surface area and causing a wrinkled appearance
TRH stimulates TSH secretion, and TSH stimulates TH release; TH increases metabolic rate. This system is a negative feedback loop. What would be the effect of decreased TSH on TRH, TH, and metabolism?
TH would decrease, metabolism would decrease,
TRH would increase
CN V conveys tactile sensory info from the cornea. Like most cranial nerves, CN V does not decussate. Therefor, damage to the right CN V will cause an inability to perceive sensory info in which cornea?
The right cornea
Blood pressure is proportionate to cardiac output and resistance. A decrease in BP will increase renin production. What effect will reduced resistance have on renin production?
Renin will increase
The pupillary reflex is a consensual response, where shining a light into the right eye causes the right CN II to convey the sensory info to the brain, and then CN III on both sides sends a motor signal to each pupil, causing them to constrict. If CN II was damaged, what would effect would shining on a light on the right eye have?
No effect - a damaged CN II can not convey sensory info to the brain to initiate a motor signal in CN III
Tubular osmolarity will increase
Consider the following negative feedback mechanism: Blood pressure is proportionate to cardiac output and resistance, and a decrease in BP will increase renin production which will help raise BP. If an individual's BP drops due to blood loss, what will happen to renin and resistance?
Renin will increase &
resistance will increase
Organophosphate flea products are often used to kill fleas on pets. They work by inhibiting acetylcholinesterase (an enzyme that breaks down excess acetylcholine in the synapse). But, these products can be toxic - what could be administered as an antidote?
An acetylcholine antagonist
Consider that low pH, high CO2, and low O2 will increase ventilation; increased CO2 will decrease pH. Given this, if a defiant child decides they are going to hold their breath in protest to not being able to do what they want to do, what will be the effect on blood CO2 levels and pH?
CO2 will increase, which
will decrease pH
Normally, glucose is reabsorbed in the renal tubules (a process which relies on carrier proteins) and not excreted in urine. In diabetes, blood glucose levels are abnormally high and glucose is excreted in the urine. Explain the role of carrier proteins in the abnormal excretion of glucose.
Glucose carrier proteins reach their threshold and are unable to facilitate reabsorption of all the glucose