Clinical Applications for Exam 1 Flashcards
Insulin Shock is a severe form of what? And what happens in this condition?
Insulin shock is a severe form of hypoglycemia. Hypoglycemia is an abnormally low concentration of glucose in blood plasma.
The brain gets insufficient glucose because glucose from blood plasma to tissue cells occurs through facilitated diffusion. And even though this diffusion is mediated by carrier proteins the concentration gradient effects the rate…and with hypoglycemia there is less of a concentration so the rate is lower. Insulin shock causes this, overdose of insulin.
Results in loss of consciousness, coma, or sometimes even death. Exercise can produce a less severe reaction because of the increased presence of Glut 4 proteins.
Endometriosis–what is it?
what did Linda’s doctor’s think the patient had that most likely caused her symptoms and fibroids?
Endometriosis- the growth of uterine tissue outside of the uterus.
-Doctor put pt. on birth control pills and gave her a shot. She had painful periods and wanted to get pregnant so the pt. then went off of the BC pills and an ultrasound showed fibroids when she had a hard time conceiving.
Dr’s believed she had polycystic ovarian syndrome.
Treatment: See a nutritionist and exercise. 1 year later she was able to conceive
MMP’s- what does it stand for?
What regulates their activity? and what do they do?
Matrix Matalloproteinases
-TIMPS inhibit MMPs when they are activated or produced improperly.
Job: enzymes that breakdown extracellular matrix. They are required for tissue remodeling and play a role in tumor expansion when they (MMPs) aren’t functioning properly, as well as the metastasis of cancers. This can happen if the MMPs breakdown extracellular matrix that allows the tumors to spread through basement membranes and into the lymphatic or cardiovascular system.
What is Dialysis?
Dialysis is the net diffusion of waste molecules from blood across a semi-permeable membrane into a fluid called dialysate.
Give examples of two types of Dialysis
Hemodialysis: Blood is channeled into an external filter system to be cleared of waste molecules.
Peritoneal Dialysis: The dialysate is introduced into the pt’s abdominal cavity and their own peritoneal cavity serves as the semi-permeable membrane.
What is Cystic Fibrosis?
Defect in what channels?
What gene causes the defect?
Side Effects?
Cystic fibrosis is a genetic condition caused by a mutation in the Cystic Fibrosis Transmembrane Conductor Regulator (CFTR) gene (over 2000 different mutations). This mutation causes formation of Cl- channels in apical membranes of epithelial cells. CFTR is formed in the endoplasmic reticulum, transported via the golgi complex to the plasma membrane and a Cl- channel is inserted into the membrane.
The side effects of those Cl- channels is abnormal NaCl and water movement across membranes of sweat glands (causes excessively salty sweat), pancreatic ductules, and small respiratory airways (formation of dense viscous mucus in the lungs and pancreas which promotes pulmonary, respiratory and pancreatic disorders).
What causes Edema?
Edema is caused when a person has a low concentration of plasma solutes. This makes it harder for H2O to return to the blood plasma from the interstitial tissues, leads to an excessive accumulation of fluid in tissues.
What disease can lead to Edema and why?
Cirrhosis (liver disease) can lead to edema because the liver usually produces albumin, the major protein in blood plasma, and in cirrhosis there is a reduced production of albumin leading to a plasma with lower solute concentrations.
Isotonic IV fluids- Name the three most commonly used IV fluids and their chemical make up.
Normal Saline: .85g of NaCl per 100ml of water = 300mOsm. When it ionizes you get 150 mOsm of Na+ and 150mOsm of Cl-.
5% Dextrose Solution (D5W): 5g of glucose per 100ml of water = 300mOsm.
Ringers Lactate: Lactate, Na+, Cl-, K+, Ca2+ ions form a 300 mOsm solution.
Name an osmotically active IV fluid and when you would use it.
Mannitol: a hypertonic, osmotically active solution. Given to treat cerebral edema because it has osmotically active solutes with higher osmolality and osmotic pressure than plasma. That causes the cells to crenate and reduces swelling by drawing H20 out from the cells/tissues and into the plasma.
–mannitol is derived from sugar mannose
Acute Gastroenteritis
What disease can cause it? What is the biggest risk from that disease? and what is the solution?
Cholera can cause acute gastroenteritis.
The main problem from this is diarrhea. Diarrhea causes an excessive loss of Na+ and water. It also leads to malnutrition and metabolic acidosis.
Solution: Oral Rehydration Therapy. A Na+/glucose solution that has specific concentrations of electrolytes and glucose to form a 245 mOsm solution. Na+ and glucose are added in the same molarity for optimum co-transport in the intestines. 2 Na+ move in bringing 1 glucose along and water follows via osmosis.
Vital Signs Story: Hypokalemic Periodic Paralysis
- What were the pt’s complaints?
- Test ordered?
- What was weird about the test?
- Clinical characteristics of the disease and what causes it?
- Pt. complained his muscles would get weak and that it comes and goes. He had it for 2-3 years.
- Electrocardiogram
- Sinus tachycardia showed, QRS complex looked normal but the ST segment was flattened, an abnormal squiggle appeared after the T wave and there was an abnormally large U wave.
Big U wave is a sign of hypokalemia. - It is a genetic disease caused by a mutation in a gene coding for Calcium channels in skeletal muscles.
SPECIFICALLY DIHYDROPYRIDINE RECEPTORS
Abnormalities in Ca2+ movement is associated with problems with K+ concentrations. Muscle cell function becomes inhibited, leading to the weakness. Can last 3 hours to 2 days. Usually this happens after meals high in carbs and salts or after strenuous exercise.
What does an electrocardiogram show?
Reflects the electrical activity of the heart
Hyperkalemia
Normal Range?
Lethal Range?
Reaction with resting membrane potential?
abnormal increase in plasma K+, causes the intracellular concentration of K+ to increase.
Normal Range: 3.5 to 5.0 mEq/L
Lethal Range: 8 mEq/L and higher. (KCl lethal injection)
-brings membrane potential closer to 0, which reduces potential.
-interferes with normal heart function, shows EKG abnormalities.
Hypokalemia
Reaction with resting membrane potential?
Abnormally low plasma K+ concentrations.
Can result from diuretics, may also cause EKG abnormalities.
The resting membrane potential depends upon the K+ concentration extracellularly and affects electrical activity of the heart.
Diabetes Mellitus
-Normal sugar and urine process vs. What happens with diabetes mellitus
Diabetes Mellitus is caused by the inadequate secretion and/or action of insulin.
Normal: glucose gets filtered out by kidneys when forming urine, but it is reabsorped into the blood by transmembrane proteins (glut 2) and so there should be little or no glucose in the urine.
In Diabetes Mellitus: hyperglycemia leads to transmembrane carriers becoming saturated and the transport maximum is exceeded. This leads to untransported glucose continuing through the renal tubules and appearing in the urine = glycosuria.
The Brain:
What is the main problem with trying to get medications into the brain?
The Blood Brain Barrier. It protects the brain and so a lot of medications that could help it can’t even get into it. The key is figuring out how to get things into the brain that can help it and easily cross the blood brain barrier.
How was the blood brain barrier discovered?
In the 1800s biologists found they could see the microscopic structure of the body more clearly if they injected tissues with special dyes. A german biologist Paul Ehrlich discovered if he injected a dye into the abdomen of animals he could color all their organs except for the brain. He followed that up by injecting the dye directly into the nervous system and that time only the brain turned blue. He concluded that there had to be a type of barrier separating the brain from the rest of the body.
What molecules were taken advantage of to try to “trojan horse” an antibody welded to erythropoietin into the brain?
Insulin and Transferrin because they both have “free passage” across the blood brain barrier.
What does Erythropoietin do?
It helps heal injured cells.
Instead of attaching a drug to an antibody and getting it past the BBB, scientists made the antibody a drug by taking advantage of what physical feature antibodies have? And what example is given in the Brain article?
They took advantage of the fact that antibodies are shaped roughly like the letter Y with two arms able to latch onto proteins. So they made one arm appear to be like a transferrin so it could attach to that specific receptor. Then when it was through the blood brain barrier the other arm swung into action.
Ex given: the other arm was engineered to grab and black beta-secretase which helps produce plaques implicated in Alzheimers disease.
Demyelinating Disease attack what specifically? What cells would that be in the PNS? in the CNS?
Demyelinating diseases attack the myelin sheath specifically. In the PNS that means Schwann cells would be attacked, and in the CNS, Oligodendrocytes would be attacked.
The immune system attacks only one or the other type of myelin.
In what disease do T cells of the immune system attack myelin sheaths of the PNS?
What are the effects?
Guillain-Barre Syndrome.
This produces rapid onset of symptoms that include muscle weakness (even muscles of breathing) due to dysfunction of somatic motor axons, and cardiac and blood pressure problems due to dysfunction of autonomic axons.
What autoimmune disease is caused by T-lymphocytes causing lymphocytes and monocyte-derived macrophages to enter the brain and target the myelin sheaths?
Multiple Sclerosis.
The inflammation produced by the macrophages causes demyelination, partial restoration due to neuroglia scarring, and axon degeneration.
What are some of the symptoms of multiple sclerosis?
Chronic remitting and relapsing disease with highly variable symptoms including sensory impairments, motor dysfunction and spasticity, bladder and intestinal problems, fatigue, and others.
What is the treatment for MS?
Treatment includes drugs that reduce autoimmune activity and inflammation, and drugs that interfere with the entry of auto-reactive T cells into the CNS. There is no cure however for this disease and no way to restore myelin sheaths.
What drugs reversibly bind to Na+ channels in the axon membrane, preventing them from opening to produce a depolarization, in this way blocking the ability of sensory axons to produce action potentials?
Local Anesthetics
What was the first local anesthetic used?
Cocaine, but its ability to be abused and unwanted side effects prompted the search for alternatives.
Procaine and then lidocaine were invented, these drugs produce what that limits the duration of their action?
They produce vasodilation, for that reason local anesthetics often also contain epinephrine or other vasopressors (cause vasoconstriction).
What are Tetanus toxin and Botulinum Toxin?
Potentially deadly bacterial products that block the release of neurotransmitters.
What type of neurotoxins are tetanus and botulinum toxins?
They are proteases that destroy specific proteins of the SNARE complex, thereby inhibiting exocytosis of neurotransmitters.
Tetanus Toxin reduces what neurotransmitters?
Neurotransmitters released from inhibitory synapses, like glycine or GABA, by attacking synaptobrevin-2.
