Integrated Physiology Review – Endocrine, Metabolism, Digestion, Renal & Acid-Base

These flashcards cover key definitions, hormone functions, metabolic pathways, digestive anatomy, renal physiology, and acid-base balance concepts likely to appear on the upcoming exam.

What is acidosis?

A buildup of acid in the bloodstream that lowers blood pH below the normal range.

What is alkalosis?

A condition in which body fluids contain too much base (alkali), raising blood pH above the normal range.

Define anabolism.

Metabolic pathways that construct larger molecules from smaller units using energy.

Define catabolism.

Metabolic processes that break down molecules into smaller units to release energy.

Define metabolism.

The sum of all chemical reactions in living organisms that maintain life, growth, and reproduction.

What is a monomer?

A small molecule that can chemically bind to other molecules to form polymers.

What is a polymer?

A large molecule composed of repeating structural units (monomers).

What are accessory digestive organs? Give two examples.

Organs that aid digestion but are not part of the main tract; e.g., liver and pancreas (others: salivary glands, gallbladder, teeth, tongue, appendix).

Which gland secretes Growth Hormone (GH) and what is its primary role?

Anterior pituitary; it stimulates growth of tissues and overall body growth.

Which hormone from the anterior pituitary stimulates the thyroid gland?

Thyroid-stimulating hormone (TSH).

What is the function of Adrenocorticotropic Hormone (ACTH)?

Regulates activity of the adrenal cortex.

Which anterior-pituitary hormone regulates gamete production?

Follicle-stimulating hormone (FSH).

Which hormone triggers estrogen or testosterone production?

Luteinizing hormone (LH) from the anterior pituitary.

What does prolactin do?

Stimulates mammary gland development and milk production.

Why is the posterior pituitary unique among endocrine glands?

It stores and releases hormones (ADH, oxytocin) made in the hypothalamus but does not synthesize them.

Which hormone increases water reabsorption in the kidneys?

Antidiuretic hormone (ADH).

Which hormone induces uterine contractions during labor?

Oxytocin.

What hormone does the pineal gland secrete and what is its effect?

Melatonin; it promotes sleep and regulates circadian rhythms.

Name the two active thyroid hormones and their broad effect.

Thyroxine (T4) and Tri-iodothyronine (T3); they raise metabolic rate in almost all body cells.

What is the role of calcitonin?

Lowers blood calcium by stimulating calcium deposition in bone.

Which hormone raises blood calcium levels and from which gland is it released?

Parathyroid hormone (PTH) from the parathyroid glands.

What does aldosterone do and from where is it secreted?

Regulates water and electrolyte balance; secreted by the adrenal cortex (mineralocorticoid).

What is the main glucocorticoid and its effect on blood glucose?

Cortisone (and cortisol); it increases blood glucose levels.

Which hormones are produced by the adrenal medulla?

Epinephrine and norepinephrine.

What is insulin’s primary action?

Decreases blood glucose by promoting glucose uptake into cells.

What is glucagon’s primary action?

Raises blood glucose by stimulating glycogen breakdown (glycogenolysis) in liver and muscle.

Which hormone produces female secondary sex characteristics?

Estrogen from the ovaries.

What role does progesterone play?

Regulates the menstrual cycle and maintains the uterus during pregnancy.

Which hormone produces male secondary sex characteristics?

Testosterone from the testes.

Briefly, how do hormones exert their effects on target cells?

Via signal-transduction pathways: the hormone binds to a receptor, triggering intracellular signaling that alters cell activity (gene expression, enzyme activity, etc.).

What are tropic hormones?

Hormones that target other endocrine glands, stimulating or inhibiting their hormone release (e.g., TSH, ACTH, FSH, LH).

How do feedback loops regulate hormone release?

Changes in hormone levels or their effects are sensed by the hypothalamus/pituitary, which adjust secretion to maintain homeostasis (negative feedback predominates).

Which pituitary part is derived from epithelium and which from nervous tissue?

Anterior pituitary—epithelial origin; posterior pituitary—nervous tissue, extension of the brain.

Which hypothalamic nucleus projects to the posterior pituitary?

Supraoptic nucleus (long axons).

Which hypothalamic nucleus releases tropic hormones to the anterior pituitary?

Arcuate nucleus (short axons to portal circulation).

What is the relationship between glucose and glycogen?

Glucose monomers polymerize into glycogen for storage; glycogen is broken down to glucose during fasting.

How are fatty acids related to triglycerides?

Three fatty acids esterify to glycerol to form a triglyceride (energy-storage fat); lipolysis reverses this.

How are amino acids related to proteins?

Proteins are polymers of amino-acid monomers linked by peptide bonds; proteolysis releases amino acids.

Provide the reactants and products of lipolysis.

Triglyceride (TAG) → glycerol + free fatty acids (FA).

Name two metabolic processes that occur during the fasted state.

Glycogenolysis in liver; lipolysis in adipose tissue (also gluconeogenesis, ketogenesis).

Which hormone dominates the fed state and what does it stimulate?

Insulin; it stimulates glycogenesis, lipogenesis, protein synthesis and inhibits gluconeogenesis.

Which hormone dominates the fasted state and what does it stimulate?

Glucagon; it stimulates glycogenolysis, gluconeogenesis, and lipolysis.

Differentiate Type-1 and Type-2 diabetes mellitus.

Type-1: autoimmune destruction of β-cells, absolute insulin deficiency. Type-2: insulin is produced but target cells become resistant after chronic high sugar exposure.

List three major energy-storage molecules.

Glycogen, triglycerides (fat), and, to a lesser extent, proteins.

Why is fat an efficient energy storage form?

High energy density (9 kcal/g) and hydrophobic nature allows compact, water-free storage.

List the major organs of the digestive tract in order from mouth to anus.

Mouth → pharynx → esophagus → stomach → small intestine (duodenum, jejunum, ileum) → large intestine → rectum → anus.

Which enzyme in saliva begins carbohydrate digestion and what does it produce?

Salivary amylase; converts starch into simple sugars (maltose, glucose).

Identify the major anatomical regions of the kidney.

Renal cortex, renal medulla

Trace urine flow from collecting duct to outside the body.

Collecting duct → minor calyx → major calyx → renal pelvis → ureter → urinary bladder → urethra → external urethral orifice.

Trace blood flow in the kidney from renal artery to peritubular capillaries.

Renal artery → segmental → interlobar → arcuate → cortical radiate → afferent arteriole → glomerulus → efferent arteriole → peritubular capillaries/vasa recta.

Name two solutes normally present in glomerular filtrate.

Water, glucose, electrolytes, amino acids, urea (any two).

How is glucose reabsorbed in the proximal convoluted tubule (PCT)?

Via secondary active transport with Na⁺ (SGLT symport) followed by facilitated diffusion into blood.

How is filtrate concentrated in the loop of Henle?

Countercurrent multiplier: descending limb loses water, ascending limb actively pumps out Na⁺/Cl⁻, creating an osmotic gradient in the medulla.

What is the normal arterial blood pH range?

7.35 – 7.45

Write the bicarbonate buffer system equation.

CO₂ + H₂O ⇌ H₂CO₃ ⇌ H⁺ + HCO₃⁻

How do the lungs regulate blood pH?

By altering CO₂ exhalation; increased ventilation removes CO₂ (raises pH), decreased ventilation retains CO₂ (lowers pH).

How do the kidneys regulate blood pH?

By reabsorbing or excreting HCO₃⁻ and secreting H⁺ in the distal nephron, adjusting plasma bicarbonate levels.

Name and classify the four main acid-base disorders.

Respiratory acidosis, respiratory alkalosis, metabolic acidosis, metabolic alkalosis.

How are H⁺ and H₂O handled in the distal convoluted tubule & collecting duct?

H⁺ secreted by proton pumps; water reabsorbed through ADH-regulated aquaporins.

What are the primary functions of renin?

Renin is an enzyme secreted by the kidneys that increases blood volume, blood pressure, and sodium reabsorption