Endo: Clinical Correlation Flashcards
Enzyme is lacking in humans that supposedly would metabolize uric acid further
Uricase
End product of purine catabolism in humans
Uric acid
Gout is generally a metabolic disorder of
Purine catabolism
Gout may be due to defects in _______ as: inc affinity for ribose-5-phosphate, defect in feedback inhibition and increased Vmax
PRPP synthetase
It is converted to inosine
Adenosine
In the pathway, what is the immediate precursor of uric acid
Xanthine
What is the underlying problem that brings about the symptom of acute gout
Renal mishandling of uric acid
Substance that is deposited in the tissues in acute gout
Monosodium urate
Characteristic of acute gouty arthritis
Monoarticular
In relation to acute gouty arthritis, serum uric acid levels are
May be normal or elevated
How does alcohol intake precipitate acute gouty arthritis
- alcohol produces lactic acid which inhibits uric acid excretion
- alcohol causes diuresis
- alcohol may alter pH affecting solubility of uric acid
Dietary component which may contribute to increased production of uric acid
Protein
Enzyme that is inhibited by the drug allopurinol
Xanthine oxidase
To facilitate excretion of uric acid, ______ drugs may be used.
Uricosuric
Mainstay of treatment for an attack of acute gouty arthritis
NSAIDS
Increase uric acid levels
Hyperuricemia
Crystals that are deposited in the tissues in acute gouty arthritis
Monosodium urate
Inflammation of tissue
Pain, Edema & Neutrophilic Infiltration “PEN”
More common in males. Middle age(40s). Sudden very painful involvement of single joint. Common history of recent alcohol intake. Serum uric acid may be normal to elevated.
Acute gout
Medical term for big toe
Podagra
Persistent hyperuricemia. May involve multiple joints/tissues. Chronic deposition of crystals resulting in tophi.
Chronic gout
Binds to microtubules; prevents migration of neutrophils.
Colchicine
Inhibits the enzyme xanthine oxidase; prevents formation of uric acid.
Allopurinol
To control inflammation
Steroids
Removal of tophi thru
Surgery
Types of arthritis
Osteoarthritis, rheumatoid arthritis and gouty arthritis
Inflammation of joint
Arthritis
Metabolic interrelationships of cells in the body: _____ & _____ must cooperate unselfishly for the common good of the body.
Cells & Organs
The physical sensation or the body’s way of signaling that is running short of food and needs to eat something is termed
Hunger
Region that has the greatest number of hungry people
Asia and the Pacific
The number of health risks worldwide include
Hunger & Malnutrition
Blood glucose and insulin levels are highest during
Immediately post-prandial
Sources of glucose in blood include
Liver glycogen, muscle glycogen & renal gluconeogenesis
Second messenger molecule of glucagon
Tyrosine kinase
Metabolic effects of glucagon on the liver include
Dec glycolysis & Inc gluconeogenesis
Glucogenic compounds that undergo gluconeogenesis include the ______. What product of glucose metabolism feeds this cycle to proceed to gluconeogenesis
Cori cycle. Lactate.
Most variable item in the energy budget of the body.
Muscle activity
Glycogenolysis in the muscle can
Inc blood glucose level
Adipocytes must undergo glycolysis before they can synthesize triglycerides because they need an intermediate of glycolysis known as
Dihydroxyacetone phosphate
The brain produces most of its energy by the oxidation of glucose; during long term fasting, however it can cover more than half of its energy needs from
Oxidation of ketone bodies
During long term fasting, the liver produces acetyl-CoA by the B-oxidation of fatty acids. What is the major metabolic fate of this acetyl-CoA
Ketogenesis
When you wake up in the morning, 12 hours after dinner, what is the main source of blood glucose
Liver glycogen
Why does net protein breakdown occur during prolonged fasting
To provide gluconeogenic substrates
What is the metabolic sequelae of low insulin levels and high levels of insulin antagonists
Enhanced lipolysis
Activates beta oxidation of fatty acids
Glucagon
The most aristocratic organ in the body by virtue of its comsumption of approximately 20% of the total energy in the resting body
Brain
Ketone bodies that are used to fuel metabolism in starvation
Acetoacetate & b-Hydroxybutyrate
A disorder with ff. manifestations: tired, fatigue, constipation, cold intolerance, dry skin, swelling sensation on neck and diminished reflexes.
Hypothyroidism
Treatment of choice for hypothyroidism
Levothyroxine
Hormone that inc protein synthesis, stimulate oxygen consumption, upregulates Na-K pump and aids in conversion of food into energy or heat
Thyroid hormone
Sequence in the synthesis of tyrosine
- Oxidation of I- to 12
- Organification of I2 into MIT & DIT
- Coupling reaction of MIT and DIT into T3 and T4
- Hydrolysis of T3 & T4
- Deiodination of residual MIT & DIT and recycling of I- and tyrosinase
Block the action of thyroid hormones, so the dose of thyroid hormone must be increased
Estrogen
Stimulatory factors for thyroid hormone secretion
TSH, Thyroid-stimulating immunoglobulins & pregnancy
Leading cause of hypothyroidism in DEVELOPED countries
Autoimmune thyroiditis
TSH levels are elevated and directly stimulate growth of the thyroid gland to a very large size
Individuals with iodide deficiency
True in patient with chronic autoimmune destruction of the thyroid gland
Inc TSH, Low BMR & Low T3 resin uptake
Thyroid hormone receptors exert their effect by binding to ___ and regulate transcription of ____ from target genes.
DNA. mRNA.
Causes the regulatory subunits of the protein kinase to dissociate from the catalytic subunits
G protein
The phosphatidylinositol cycle begins with activation of _________; this initiates a sequence of events.
Phospholipase C
Elevated TSH, Low thyroxine
Hypothyroidism
Sheehan sydrome/ anterior pituitary hemorrhagic necrosis after postpartum hemorrhage. She feels light headed, dizzy and weak. What hormone is responsible
ACTH
Thyroglobulin is derived from what AA
Tyrosine
A functional bowel disorder. Symptoms are abdominal pain, or discomfort and altered bowel habits in absence of detectable structural abnormalities.
Irritable Bowel Syndrome
Rome II Criteria: recurrent abdominal pain or discomfort of atleast _____ per month in the last ______ associated with __ or more of the ff: improvement w/ defecation, onset associated with a change in frequency or in appearance of stool
3 rays. 3 months. 2.
Extrinsic innervation of Digestive system
Para and sympathetic
Intrinsic innervation of Digestive system
Meissner’s plexus & Auerbach’s plexus
Contraction and relaxation of the walls and sphincters of the GIT. Grinds, mixes and fragments ingested food and propel it slong digestive tract.
Motility
Grinds and mixes food
Segmentation
Propels food
Peristalsis
Periodic contractions followed by relaxation. For mixing and propulsion. Threshold depolarization.
Phasic contraction
Maintained level of contraction or tone without regular periods of relaxation. Subthreshold depolarization.
Tonic contraction
Are not action potential but rather oscillating depolarization and repolarization of the membrane potential of the smooth muscle cells
Slow waves
Origin of slow waves. Pacemaker. Found in myenteric plexus.
Interstitial cells of Cajal
Frequency of slow waves
3 waves per minute
12 waves per min in the duodenum
Slow waves depolarizing phase
Opening of Ca channels
Slow waves repolarizing phase
Opening of K channels
As the rectum fills with feces, the smooth muscle wall of the rectum contracts and the internal anal sphincter relaxes in the
Rectosphincteric reflex
The chemical breakdown of ingested foods into absorbable molecules
Digestion
Movement of nutrients, water and electrolytes from the GIT to the blood
Absorption
Carbohydrate absorption: product and site
Monosaccharides. Small intestine.
Products of protein digestion
AA, dipeptides, tripeptides
Site of absorption of protein
Small intestine
Products of lipid digestion
FA, monoglycerol & cholesterol
Site of absorption of lipids
Small intestine
In lipid digestion, Bile salts form ______ in the small intestine. ________ in the cell to triglycerides and phospholipids.
Micelles. Reesterification.
In lipid digestion, ________ form in the cell (requiring ______) and are transferred to lymph.
Chylomicrons. Apoproteins.