Endocrine
These types of hormones, which include peptides, travel freely in the blood and bind to cell-surface receptors rather than intracellular receptors.
What are water-soluble (or hydrophilic) hormones?
These specialized endocrine cells, located within the thyroid gland, are responsible for producing calcitonin to help regulate calcium levels.
What are Parafollicular cells (or C cells)?
This cup-shaped structure surrounds the glomerulus and collects the initial filtered blood plasma to form the glomerular filtrate.
What is Bowman's capsule?
A urine specific gravity (USG) consistently measuring between 1.007 and 1.013, indicating the urine osmolality is exactly the same as plasma osmolality, is known by this term.
What is isosthenuria?
It is the largest gland in the animal body and is responsible for metabolic regulation, detoxification, and the production of bile.
What is the liver?
Secreted by chromaffin cells, this specific hormone accounts for 80% of the catecholamines released by the adrenal medulla during a "fight or flight" response.
What is epinephrine (or adrenaline)?
This biologically active peptide is cleaved from the insulin precursor, co-secreted with insulin in equimolar amounts, and is used diagnostically as a marker for insulin secretion.
What is C-Peptide?
These specialized epithelial cells form part of the glomerular filtration barrier using their foot-like projections to wrap around the capillaries.
What are podocytes?
Severe dehydration or hypovolemic shock causing decreased renal blood flow leads to this specific classification of azotemia.
What is prerenal azotemia?
The rhythmic contractions of the circular smooth muscle in the intestines that are specifically designed to mix ingesta.
What is segmentation?
Produced in the hypothalamus and stored in the posterior pituitary, this hormone acts on V2 receptors in the kidney to promote the reabsorption of facultative water.
What is Anti-Diuretic Hormone (ADH / Vasopressin)?
This specific laboratory analyte is the first-line screening test used to diagnose hyperthyroidism, a condition frequently seen in older cats.
What is Total T4 (TT4)?
Known for performing "bulk reabsorption," this segment of the nephron recovers 100% of filtered glucose and amino acids, and roughly 65-70% of filtered water and sodium.
What is the proximal convoluted tubule (PCT)?
The hormone aldosterone regulates blood volume by stimulating the reabsorption of sodium and the secretion of this major intracellular cation into the urine.
What is potassium (K+)?
In cattle and sheep, the hepatic production of these metabolic byproducts (such as beta-hydroxybutyrate) spikes during a negative energy balance, leading to a condition common in early lactation or late pregnancy.
What are ketone bodies? (Acceptable: What is ketosis?)
The excessive production of this glucocorticoid hormone causes the "5 P's," which include polyuria, polydipsia, polyphagia, panting, and a pendulous abdomen.
What is cortisol?
Glucosuria and osmotic diuresis occur in Diabetes Mellitus because the blood glucose level exceeds this specific absorption limit in the kidneys.
What is the renal threshold?
In the loop of Henle, the thick ascending limb is highly permeable to these, but completely impermeable to water.
What are solutes (or electrolytes / NaCl / sodium and chloride)?
An increase in this calculated amount (Sodium minus [Chloride + Bicarbonate]) is often seen in metabolic acidosis due to the accumulation of unmeasured anions like ketones, lactate, or uremic acids.
What is the Anion Gap?
During the intestinal phase of digestion, this hormone is released from duodenal endocrine cells when the pH of chyme drops below 4.5, stimulating the pancreas to secrete bicarbonate.
What is secretin?
In the male hypothalamic-pituitary-gonadal axis, this substance is produced by Sertoli cells to selectively inhibit the release of Follicle Stimulating Hormone (FSH).
What is Inhibin?
The synthesis of the thyroid hormones T3 and T4 requires the integration of these two specific building blocks.
What are iodine and tyrosine?
These specialized cells in the distal tubule sense sodium chloride concentrations in the filtrate to regulate the Glomerular Filtration Rate (GFR) via tubuloglomerular feedback.
What is the macula densa?
Produced by all nucleated cells at a constant rate, this specific biomarker is considered more sensitive than serum creatinine for detecting an early decline in GFR in dogs and cats.
What is Symmetric dimethylarginine (SDMA)?
When evaluating a chemistry panel, these two specific "leakage enzymes" are commonly used to detect hepatocellular damage or necrosis, differentiating it from cholestasis.
What are ALT (Alanine aminotransferase) and AST (Aspartate aminotransferase)?