Test 1 clinical applications/Investigations

Question 1

MMP stands for what?

What is the normal function of MMP:

Answer 1

Matrix metalloproteinases

Tissue remodeling (embryonic development and cell migration of phagocytic cells and other WBCs)

Question 2

What stops matrix metalloproteinases from degrading intracellular proteins?

Answer 2

MMPs are activated extracellularly

Question 3

How can MMPs contribute to disease?

What exists to stop these?

Answer 3

MMPs can contribute to disease by helping tumors metastasize and invade different locations. They can also contribute to disease if activated inappropriately.
MMPs are inhibited by
TIMPs

Question 4

What are some generic examples of diseases that MMPs may be involved in?

Answer 4

Cancer migratino
Destruction of Cartilage protein in arthritis
Cardiovascular and neural disease (from an imbalance in TIMPs and MMPs)

Question 5

Hemodialysis:

Peritoneal dialysis:

Answer 5

Hemodialysis: Blood is channeled to an external filtering system
Peritoneal dialysis: a dialysate is introduced into the peritoneal cavity, where the peritoneal membrane serves as the semipermeable membrane.

Question 6

Dialysate:

Answer 6

Net diffusion of waste molecules from blood into the dialysate (the fluid it is diffused into)

Question 7

What necessitates dialysis?

Answer 7

Inability of the kidney to filter (kidney/renal failure)

Question 8

What are the symptoms of cystic fibrosis:

Answer 8

Excessively salty sweat, mucous build up in the pancreas and lung (promoting pancreatic and pulmonary disorders)

Question 9

What is the molecular cause of cystic fibrosis:

Answer 9

A genetic defect in a glycoprotein known as CFTR (cystic fibrosis transmembrane conductance regulator) causes it to not be placed in the golgi complex for processing, and is incorrectly inserted into the plasma membrane

Question 10

Are all cases of cystic fibrosis equally severe?

Is the disease curable/treateable?

Answer 10

Different mutations cause CFTR gene which can have cystic fibrosis of differing severity.
It is not curable but it is treatable.

Question 11

Why are plasma proteins concentrated in the bloodstream?

What results if there is an abnormally low level of plasma proteins?

Answer 11

They cannot exit through the capillary pores, they are therefore osmotically active
The osmotic pressure from plasma proteins draws fluid from the interstitial fluid into the blood. Without this osmotic pressure edema occurs.

Question 12

What underlying condition may cause there to be inadequate levels of protein in the blood and edema?

Answer 12

Cirrhosis of the liver can stop it from producing albumin. As albumin is osmotically active, it causes a drop in the osmolality of the blood and a flow of water into the interstitial fluid (edema)

Question 13

What is in Ringer’s lactate:

Answer 13

Lactate, and Na, Cl, K, and Ca

Question 14

Why is mannitol sometimes given intravenously to patients in the hospital?

Answer 14

Mannitol is osmotically active, and it will draw fluid out of other tissues. This can stop cerebral edema for example.

Question 15

Why does hyperglycemia (as seen in diabetes mellitus) cause glycosuria

Answer 15

Sugar normally enters the urine and is pumped out by Na+/Glucose symport pumps. In patients with hyperglycemia these pumps become saturated and cannot pump out all the glucose in the urine.
Their transport maximum (Tm) is exceeded.

Question 16

Why does hypoglycemia result in symptoms of the brain getting inadequate glucose?

Answer 16

Glucose transport into the brain, is a facilitated transport using GLUT1 and GLUT3 transporters, it relies on the concentration gradient.

Question 17

What can cause severe hypoglycemia?

What results from severe hypoglycemia

Answer 17

Insulin overdose

Failure of glucose to diffuse into the brain. Loss of consciousness or death can ensue.

Question 18

What are the resulting conditions from acute gastroenteritis:

Answer 18

Diarrhea produces loss of Na+ and water, malnutrition, and metabolic acidosis. Kills 1.5 - 2.5 million deaths.

Question 19

ORT: what does it stand for and what is it.

Answer 19

Oral rehydration therapy
Na+ and glucose symport into the intestine pulls water into the body through osmosis. A solution of 245 mOsm, Na+ and glucose should be in equal concentration for ideal cotransport conditions to occur.

Question 20

What is the normal plasma K+ concentration?
What concentration can stop the heartbeat?
Why?

Answer 20

3.5 to 5.0 mEq/L
> 8 mEq/L
Depolarization of cells (lower resting membrane)

Question 21

Hypokalemia effect on the body:

Answer 21

hyperpolarization of cells, cells are harder to activate resulting in slowing down of muscles and nervous system. Weakness and fatigue. Irregular large U wave, inverted T wave

Question 22

What two categories of demyelinating disease:

Answer 22

Targeting the CNS: Multiple sclerosis

Targeting the PNS: Guillain-Barre syndrome

Question 23

Guillain-Barre syndrome:

Answer 23

T cells attack the myelin sheaths of the PNS. Rapid onset of symptoms, such as muscle weakness (which can cause respiratory failure), autonomic axons also cause issues in blood pressure and cardiac regulation as they are demyelinated

Question 24

Multiple Sclerosis:

• Description:
• Target population:
• Treatment:

Answer 24

• Description:
  Attack mediated by T cells on the myelin sheaths of the CNS. Leading to areas of hardening (sclerosis) followed by degeneration. Chronic relapsing disease with variable symptoms, such as sensory impairments, motor disfunction, and difficulty with bladder and fatigue
• Target population:
  Manifests ages 20 - 40 twice as prevalent in females
• Treatment:
  Drugs which decrease autoimmune activity and drugs which interfere with the entry of T cells in the CNS. Help with symptoms but do not restore myelin sheaths or cure disease

Question 25

What mechanism do local anesthetics utilize:

Answer 25

They reversibly bind voltage gated Na+ channels and prevent action potentials

Question 26

What was the first local anesthetic:

What else was used as alternative anesthetics:

Answer 26

Cocaine

Procaine, Lidocaine

Question 27

Procaine, lidocaine and others like them often have what other type of drug with them? Why?

Answer 27

A vasopressor such as epinephrine

Procaine and lidocaine cause vasodilation which limit their usefulness, epinephrine reverses this

Question 28

What is the mechanism of action of Botulinum toxin:

Answer 28

Digests (botulinum toxin is a protease) SNAP-25 in excitatory synapses which release Acetylcholine.

Question 29

What is the result of botulinum toxins actions:

Answer 29

flaccid paralysis, muscles are unable to react. small amounts of this toxin in botox treatments smooth wrinkles.

Question 30

What is the mechanism of action of tetanus toxin:

Answer 30

Targets inhibitory synapses, such as glycine and GABA by digesting synaptobrevin-2.

Question 31

What is the result of tetanus toxin actions:

Answer 31

muscle rigidity, and spastic paralysis

Question 32

Myasthenia gravis:

• What is it:
• Symptoms:
• How is it treated:

Answer 32

• What is it:
  autoimmune disease which inactivates Ach receptors in the motor end plate
• Symptoms:
  Muscle weakness, particularly in the eyes, eyelids and face
• How is it treated:
  Neostigmine and other drugs which block acetylcholinesterase treats symptoms

Question 33

Neostigmine treats what disorder:

Answer 33

Myasthenia gravis

Question 34

Saxitoxin:

• Mechanism of action:
• Source:
• Cause of death:

Answer 34

• mechanism of action:
  Binds to and inactivates voltage gated Na+ channels
• Source:
  dinoflagellates which become concentrated in filter-feeding clams and mussels
• Cause of death:
  Diaphragm paralysis

Question 35

Tetrodoxin:

• Mechanism of action:
• Source:
• Cause of death:

Answer 35

- Mechanism of action:
Binds to and inactivates voltage gated Na+ channels
- Source:
Puffer fish
- Cause of death:
Diaphragm paralysis

Question 36

Cholinesterase inhibitors:

• Mechanism:
• Medicinal application:
• War and agricultural use:

Answer 36

• Mechanism:
  Inhibit cholinesterase (acetylcholinesterase)
• Medicinal application:
  Neostigmine and other medicines use this to combat low AcH levels for disorders like myasthenia gravis
• War and agricultural use:
  Nerve gas kills by inhibiting AChE and therefore overstimulating cholinergic synapses
  Organophosphate pesticides also kill by inhibiting AChE and therefore overstimulating cholinergic synapses

Question 37

Monoamine oxidase define:

Answer 37

This is a enzyme in presynaptic cells which breaks down monoamines (dopamine, norepinephrine, serotonin)
There is a transporter which transports monoamines back into the presynaptic cell for destruction

Question 38

Monamine oxidase inhibitors:

• What they do:
• Result:
• Disorders treated:

Answer 38

• What they do:
  deactivate monoamine oxidases
• Result:
  Rise in monoamines at the synapse (dopamine, melatonin, serotnin, norepinephrine being an example)
• Disorders treated:
  Depression, anxiety, panic disorder, and Parkinson’s disease.

Question 39

What can go wrong as a result of treatment with MAOIs?

Answer 39

The body cannot break down certain amino acids high in monoamines such as tyramine (derived from tyrosine, the source of catecholamines such as dopamine, norepinephrine, and epinephrine) and Tryptophan (the molecule from which serotonin is derived).
Consumption of these foods results in increased norepinephrine released by sympathetic axons increasing heart rate and driving up blood pressure (hypertensive crisis: extremely high blood pressure).

Question 40

Mesolimbic dopamine system is currently associated with what?

Answer 40

Reward and behavior

Question 41

Cocaine:

- Mechanisms of action:

Answer 41

• Mechanisms of action:
  Blocks reuptake of dopamine, serotonin and norepinephrine.
  Blocks membrane Na+ channels

Question 42

What does stimulus by cocaine activate?

Answer 42

Mesolymbic dopaminic pathway (mesolymbic reward pathway) this results in increased dopamine in the reward pathway, and happy people.

Question 43

What are the negative side-effects of cocaine?

What would the ideal cocaine be like?

Answer 43

Restricts coronary arteries, raises cardiac rate and blood pressure (norepinephrine sympathetic innervation?), promotes heart disease, stroke, seizures and ulcers.

It would block reuptake of only dopamine, and only in the mesolymbic dopamine pathway.