Phys 72 Flashcards

What is the recommended daily protein intake for a typical healthy adult?

A) 0.2 g/kg/day

B) 1.8 g/kg/day

C) 2.5 g/kg/day

D) 0.8 g/kg/day

What is the respiratory quotient for carbohydrate metabolism?

A) 0.7

B) 1.0

C) 0.8

D) 0.9

What is the respiratory quotient for fat metabolism?

A) 0.7

B) 0.8

C) 0.9

D) 1.0

What is the approximate respiratory quotient for protein metabolism?

A) 1.0

B) 0.7

C) 0.8

D) 1.2

Stimulation of which hypothalamic region classically produces intense hunger?

A) Ventromedial nucleus

B) Lateral hypothalamus

C) Dorsomedial nucleus

D) Paraventricular nucleus

Damage to the lateral hypothalamus classically produces which effect?

A) Increased appetite

B) Increased adiposity

C) Hyperphagia

D) Reduced feeding

Which hypothalamic region is classically considered the satiety center?

A) Arcuate nucleus

B) Ventromedial nucleus

C) Lateral hypothalamus

D) Suprachiasmatic nucleus

Destruction of the ventromedial hypothalamic region classically produces which effect?

A) Hyperphagia and obesity

B) Aphagia and weight loss

C) Reduced food motivation

D) Increased energy expenditure

Activation of hypothalamic POMC neurons produces which behavioral effect?

A) Reduced appetite

B) Increased hunger

C) Increased feeding

D) Enhanced food seeking

Which peptide is released by POMC neurons to suppress appetite?

A) Alpha-MSH

B) Ghrelin

C) Neuropeptide Y

D) AgRP

Alpha-MSH primarily suppresses feeding through activation of which receptor?

A) Insulin receptor

B) Ghrelin receptor

C) Leptin receptor

D) Melanocortin-4 receptor

Which hypothalamic nucleus contains important MC4R-expressing neurons that suppress feeding?

A) Suprachiasmatic nucleus

B) Arcuate nucleus

C) Paraventricular nucleus

D) Mammillary nucleus

Which hypothalamic neurons promote hunger and food intake?

A) POMC neurons

B) CART neurons

C) NPY/AgRP neurons

D) Oxytocin neurons

Which brainstem structure integrates signals involved in appetite and energy balance?

A) Inferior colliculus

B) Nucleus tractus solitarius

C) Substantia nigra

D) Red nucleus

Which hypothalamic nucleus contains neurons that release neuropeptide Y and AgRP?

A) Arcuate nucleus

B) Suprachiasmatic nucleus

C) Mammillary nucleus

D) Posterior hypothalamic nucleus

What is the main effect of neuropeptide Y on feeding behavior?

A) Inhibits appetite

B) Increases satiety

C) Reduces food motivation

D) Stimulates hunger

Damage to which limbic structure can alter feeding behavior and food preferences?

A) Hippocampus

B) Thalamus

C) Amygdala

D) Cerebellum

How does excessive gastric distention affect food intake?

A) Stimulates hunger

B) Inhibits feeding

C) Increases ghrelin secretion

D) Activates orexigenic neurons

Which intestinal nutrients primarily stimulate CCK secretion?

A) Fats and proteins

B) Water and sodium

C) Glucose and galactose

D) Calcium and magnesium

What is the primary effect of CCK on appetite?

A) Increases hunger

B) Stimulates NPY secretion

C) Suppresses satiety

D) Promotes satiety

Which gastrointestinal hormone increases after meals, particularly meals containing fat?

A) Ghrelin

B) Motilin

C) Peptide YY

D) Gastrin

What is the effect of peptide YY on food intake?

A) Increases food intake

B) Reduces food intake

C) Stimulates gastric hunger

D) Increases ghrelin secretion

Which intestinal hormone increases glucose-dependent insulin secretion after a meal?

A) GLP-1

B) Ghrelin

C) Motilin

D) Somatostatin

What is the primary effect of GLP-1 on pancreatic beta cells?

A) Inhibits insulin production

B) Increases glucagon secretion

C) Blocks glucose transport

D) Stimulates glucose-dependent insulin secretion

Which hormone is released primarily by gastric X/A-like cells to stimulate hunger?

A) Leptin

B) Peptide YY

C) Ghrelin

D) Secretin

What is the primary effect of ghrelin on feeding?

A) Suppresses appetite

B) Increases appetite

C) Inhibits food seeking

D) Promotes satiety

In classical hypothalamic models, increased glucose availability stimulates which satiety-associated region?

A) Ventromedial hypothalamus

B) Lateral hypothalamus

C) Posterior hypothalamus

D) Mammillary bodies

Which hypothalamic region classically shows reduced feeding-related activity when glucose availability increases?

A) Paraventricular nucleus

B) Ventromedial nucleus

C) Arcuate nucleus

D) Lateral hypothalamus

Which cells primarily secrete leptin?

A) Gastric chief cells

B) Pancreatic alpha cells

C) Adipocytes

D) Intestinal goblet cells

What physiological information does circulating leptin primarily signal to the brain?

A) Immediate blood oxygen concentration

B) Stored energy availability

C) Acute gastric acidity

D) Circulating calcium concentration

What effect does leptin have on hypothalamic NPY/AgRP neurons?

A) Inhibits their activity

B) Stimulates their activity

C) Increases ghrelin secretion

D) Promotes orexigenic signaling

Which combination describes leptin's effects on hypothalamic appetite pathways?

A) Increases NPY, decreases POMC

B) Increases AgRP, decreases alpha-MSH

C) Inhibits POMC, stimulates ghrelin

D) Inhibits NPY/AgRP, stimulates POMC

Which metabolic effects are generally promoted by leptin signaling?

A) Increased appetite and energy storage

B) Decreased sympathetic activity

C) Reduced appetite and increased energy expenditure

D) Increased NPY and AgRP release

Which additional hypothalamic peptide can increase in response to leptin signaling?

A) Ghrelin

B) Corticotropin-releasing hormone

C) Neuropeptide Y

D) Agouti-related peptide

Defective leptin receptor signaling can cause which clinical condition?

A) Severe early-onset obesity

B) Primary adrenal insufficiency

C) Central diabetes insipidus

D) Hyperthyroidism

What is the mechanism of action of phentermine?

A) Serotonin receptor blockade

B) Sympathomimetic activity

C) Lipase inhibition

D) Histamine receptor antagonism

How does phentermine affect feeding and energy use?

A) Decreases intake and expenditure

B) Increases intake and expenditure

C) Increases intake and decreases expenditure

D) Decreases intake and increases expenditure

Which drug used with phentermine is an anticonvulsant?

A) Demeclocycline

B) Orlistat

C) Topiramate

D) Lorcaserin

Which drug class best describes lorcaserin?

A) Lipase inhibitor

B) Dopamine receptor antagonist

C) Adrenergic receptor blocker

D) Serotonin receptor agonist

Lorcaserin increases expression of which hypothalamic precursor?

A) AgRP

B) Ghrelin

C) NPY

D) POMC

What is the mechanism of action of orlistat?

A) Protease inhibition

B) Lipase inhibition

C) Lactase inhibition

D) Amylase inhibition

Night blindness and corneal keratinization indicate deficiency of which vitamin?

A) Vitamin E

B) Vitamin D

C) Vitamin A

D) Vitamin K

Thiamine acts as a cofactor for which enzymes?

A) Decarboxylases

B) Kinases

C) Phosphatases

D) Ligases

Which vitamin deficiency causes beriberi, polyneuritis, and heart failure?

A) Vitamin B3

B) Vitamin B5

C) Vitamin B2

D) Vitamin B1

Riboflavin is needed to produce which coenzymes?

A) THF and DHF

B) CoA and ACP

C) FMN and FAD

D) NAD and NADP

Which vitamin deficiency can cause dermatitis, muscle spasticity, and severe vomiting?

A) Vitamin B6

B) Vitamin B1

C) Vitamin B2

D) Vitamin B3

Niacin serves as a precursor for which coenzyme?

A) NAD

B) FAD

C) Biotin

D) CoA

Which vitamin deficiency causes pellagra and cracked, scaly skin?

A) Vitamin B6

B) Vitamin B3

C) Vitamin B5

D) Vitamin B2

Pantothenic acid is required to form which coenzyme?

A) Coenzyme A

B) Coenzyme Q

C) NAD D) FAD

Which vitamin deficiency can cause poor growth, hair graying, and adrenocortical necrosis?

A) Vitamin B12

B) Vitamin B1

C) Vitamin B5

D) Vitamin B6

Pyridoxine functions as a coenzyme for which enzymes?

A) Transaminases

B) Amylases

C) Lipases

D) Nucleases

Which vitamin deficiency can cause sideroblastic anemia, dermatitis, and decreased growth?

A) Vitamin B2

B) Vitamin B6

C) Vitamin B9

D) Vitamin B12

Which vitamin deficiency causes dorsal column degeneration and megaloblastic anemia?

A) Vitamin B1

B) Vitamin B6

C) Vitamin B9

D) Vitamin B12

Deficiency of intrinsic factor impairs absorption of which vitamin?

A) Vitamin C

B) Vitamin B12

C) Vitamin B6

D) Vitamin B9

Folic acid supports synthesis of which compounds?

A) Collagen and elastin

B) Triglycerides and cholesterol

C) Heme and bile acids

D) Purines and thymine

Which vitamin is necessary for prolyl hydroxylase activity in collagen synthesis?

A) Vitamin C

B) Vitamin D

C) Vitamin A

D) Vitamin E

What is a principal action of vitamin D?

A) Increases intestinal calcium absorption

B) Decreases intestinal calcium absorption

C) Blocks renal calcium reabsorption

D) Inhibits bone mineralization

Which vitamin deficiency can cause germinal epithelial degeneration and sterility?

A) Vitamin K

B) Vitamin A

C) Vitamin E

D) Vitamin D

Which vitamin helps prevent oxidation of unsaturated fats?

A) Vitamin B2

B) Vitamin D

C) Vitamin C

D) Vitamin E

Which central nervous system effect can occur with excess magnesium?

A) Increased arousal

B) CNS depression

C) CNS excitation

D) Increased alertness

According to these notes, excess magnesium can cause which skeletal muscle effect?

A) Skeletal muscle contraction

B) Skeletal muscle atrophy

C) Skeletal muscle hypertrophy

D) Skeletal muscle regeneration

Which mineral is used to reverse magnesium toxicity?

A) Sodium

B) Iron

C) Calcium

D) Potassium

Low magnesium after acute myocardial infarction can precipitate what?

A) Corneal keratinization

B) Megaloblastic anemia

C) Pigment gallstones

D) Cardiac arrhythmias

Which neuromuscular manifestation is characteristic of hypocalcemia?

A) Tetany

B) Muscle atrophy

C) Areflexia

D) Flaccid paralysis

Severe hypercalcemia can cause cardiac arrest in which phase?

A) Diastole

B) Early filling

C) Systole

D) Atrial relaxation

Which mental effect can occur with elevated calcium?

A) Increased concentration

B) Mental depression

C) Heightened alertness

D) Accelerated thinking

Zinc is a component of which enzyme pair?

A) Amylase and pancreatic lipase

B) Carbonic anhydrase and lactate dehydrogenase

C) Pepsin and trypsin

D) Hexokinase and phosphofructokinase