General Physiology Review Flashcards
You order a blood test. When you receive the lab report there is a note that the blood was lysed when it was drawn. Which of the following readings could be erroneously (incorrectly) elevated?
Potassium because you have high potassium inside the cells, and if the RBCs are all lysed, then you will have a high potassium level just floating around
Which of the following would require energy? A) Na into cell B) glucose into cell C) K into cell D) chloride into cell
Potassium into cell (c)
Sodium, chloride, and bicarb are where primarily?
ECF
Would lysing RBCs have an affect on the extracellular concentration of:
1) sodium
2) potassium
3) chloride
4) bicarb
1) no
2) yes!
3) no
4) no
If we open up a sodium channel on the cell membrane, which way does it flow?
Into the cell
How often do cells need glucose?
All the time. They are pretty much starved for it at all times. Therefore, it won’t really need energy to get into the cells
Where is there a lot of chloride?
ECF (outside the cell)
What would cause the membrane potential to become more negative?
Closure of sodium leak channel
What would closing of a potassium leak channel do to the cell?
Trapping positive charge (potassium) inside cell, making it more positive
What would closing of a chloride leak channel do to the cell?
Chloride wants to move into cell, adding negative charges, making membrane potential more negative if it is open; if it is closed, it will be less negative b/c we are stopping the addition of negative charges
What would closing of an aquaporin channel do to the cell?
Won’t move water..who cares?
What would closing of a sodium leak channel do to the cell?
Sodium moves into the cell, adding positive charges into the cell, making it more positive; if this is closed, it would make it more negative
Closure of what channel is very important in phototransduction?
Sodium channel
Which junction is the most restsrictive celllular junction?
Tight junction
What makes up gap junctions?
6 connexins
Where are gap junctions found?
Smooth muscle
(Where you have to have very coordinated movement)
Vascular muscle (bladder, gut)
Are gap junctions chemical or electrical junctions?
Electrical
Structural spot-welds for support
Anchoring junctions
Cell-to-cell anchoring junctions
Desmosomes
Cell to ECM anchoring junctions
Hemidesmosomes
Areas where tight junctions are found
Eye, brain, testes
Junction where cell membranes touch, and are super restrictive, where most movement is transcellular
Zonula occluden
Where are zonula occludens found?
Blood-brain barrier
Junction where the space between cellular membranes varies and filtration can occur
Zonula adherens
Where are zonula adherens found?
Kidney, blood vessels
During aqueous humor production, sodium is actively pumped into the anterior chamber. What occurs due to this?
-Water follows through aquaporins
(Na was pumped through tight junctions)
-Potassium moves in opposite direction
-Chloride follows through ion channels if it can
-Bicarbonate follows through ion channels
During urine production, glucose is actively pumped into the cell. What occurs due to this?
Create concentration difference of a molecule that cannot cross a membrane, generating osmotic pressure, pulling water with it
Administration of a(n) _____ will increase aqueous humor production
Beta 2 agonist
Role of alpha 1 receptors
Pupil dilation
Are alpha receptors sympathetics or parasympathetics?
Sympathetics
Role of alpha 2 receptors
Reduce aqueous humor formation by reducing B2 release
What can you give pt’s who have some open angle glaucoma in order to reduce production of aqueous humor
Beta blockers
Role of beta 2 receptors
- Ciliary relaxation for distance
- Increase aqueous humor production
Are beta 2 receptors in the eye sympathetics or parasympathetics?
Sympathetics
