Basic Physiology

Question 1

What are the major extracellular fluid ions?

Answer 1

Na+ and HCO3-

Question 2

What are the major intracellular fluid ions?

Answer 2

K+ and Mg2+

Question 3

What is the most common transporter in the body?

Answer 3

Na+/K+ ATPase (Na+ from ICF to ECF and K+ from ECF to ICF = both transported against gradients)

Question 4

What helps to maintain intracellular Ca2+ low?

Answer 4

Ca2+ ATPase transporter (pumps against gradient)

Question 5

What is amphipathic?

Answer 5

Has both hydrophilic and hydrophobic properties (ex: plasma membrane)

Question 6

What two ions establish the resting membrane potential?

Answer 6

K+ (established by N+/K+ ATPase) and Cl-

Both are highly permeable

Question 7

What is the basis for the absolute refractory period?

Answer 7

Closure of inactivation gates in Na+ channels in response to depolarization

Question 8

What is saltory conduction?

Answer 8

Jumping of action potential from nodes of Ranvier in myelinated nerves

Question 9

What is excitatory postsynaptic potentials?

Answer 9

Depolarizations that result in AP = Opening of Na+ and K+ channels
Caused by: Ach, Norepi, epi, dopamine, glutamine, and serotonin

Question 10

What is inhibitory postsynaptic potentials?

Answer 10

Hyperpolarization = NO action potential! = Opening of Cl- channels
Caused by: GABA and glycine

Question 11

What is different about smooth muclse excitation contraction coupling compared to skeletal muscle?

Answer 11

Actin and myosin controlled by binding of Ca2= to calmodulin (instead of troponin C) - which regulates myosin light chain kinase which regulates cross bridge cycling = tension

Question 12

What are purines?

Answer 12

Adenine and Guanine

Question 13

What are pyrimidines?

Answer 13

Thymine and Cytosine

Question 14

What are the 2 ways the RNA differs from DNA?

Answer 14

Ribose instead of deoxyribose

Uses uracil in place of thymine (U-A)