Hormones Flashcards
What is aldosterone, where is it made and what does it do?
A principle mineralocorticoid produced by the adrenal glands. Controls renal reabsorption of sodium and secretion of potassium.
Where in the nephron does aldosterone act on?
DCT, primarily acts on the cortical collecting ducts
Where is the thyroid gland located?
On the trachea
What effect does the thyroid have on the body?
Calorigenic effect, which influences the metabolic rate and helps maintain internal temperature and increase heat
What are the 2 catecholamines?
Epinephrine and norepinephrine
Are catecholamines hydrophobic or hydrophilic?
Hydrophilic
Are thyroid hormones hydrophobic or hydrophilic?
Hydrophobic and require transport proteins
What are 5 steroid hormones?
Androgens, Estrogens, Gluccocorticoids, Mineralocortiocoids, Progestins
What are peptide hormones?
Hydrophilic chains of a few to 200 amino acids
List the peptide hormones
ACTH, ADH, FSH, GH, LH, Calcitonin, Erythropoietin, Insulin, Glucagon, MSH, PTH, TSH, Gastrin, Cholecystokinin, prolactin, relaxin, secretin, melatonin, oxytocin
What are steroid hormones?
Hydrophobic lipids that are synthesized from cholesterol
What is a bound or unbound hormone?
A bound hormone is attached to a protein to travel in the plasma. An unbound hormone isn’t attached, and can leave the bloodstream to reach the target cell.
Which system is a ductless system?
Endocrine system
How are hormone levels regulated?
Through a negative feedback system, where activity is decreased by rising levels of hormone
What is a positive feedback system?
If the activity is increased due to falling hormone levels
Which organs produces TSH
Anterior pituitary gland
What 7 hormones are secreted by the anterior pituitary gland?
GH, prolactin, TSH, ACTH, FSH, LH, MSH
What is another name for the posterior pituitary gland?
Neurohypophosis
What 2 hormones are produced by the hypothalamus and is stored in the posterior pituitary gland?
ADH and oxytocin
Where is the pituitary located?
In a small pocket of the sphenoid bone called the pituitary fossa
The hypothalamus is attached to which other hormone secreting organ?
Pituitary
What is the name of the blood vessels that link the hypothalamus to the pituitary?
Portal system
What does prolactin help do?
Triggers and maintains lactation as long the mammary gland is stimulated
What does GH help do?
Promote growth in young animals, by encouraging anabolism of proteins and catabolism of fat, and discouraging glucose use, causing transient hyperglycemia mitigated by insulin
Lack or excess of GH causes what?
Lack causes dwarfism while excess causes gigantism.
What does TSH do?
aka thyrotropic hormone, stimulates growth of thyroid gland
What do ACTH do?
Stimulates growth of adrenal gland cortex
What does FSH do?
Stimulates the growth follicles in the ovaries and lining cells of the follicles to produce and secrete estrogens
What are follicles in the female repro system for?
Each follicle is a fluid filled structure for a single oocyte, which develops and matures as the follicle enlarges, called oogenesis.
Which hormones are responsible for female behavior?
Estrogens
What happens to hormones as follicles continue to grow?
FSH gradually decreases and LH increases. When LH peaks, ovulation occurs.
What is thyroid hormone’s effect on protein, carbs and lipids?
Encourages anabolism if proteins if there’s enough nutritionally, and catabolism on carbs and lipids. If there’s not enough proteins, then protein catabolism can occur.
Thyroid hormone has what effect besides metabolism?
Influences development of CNS, muscles and bones
What are 2 hormones produced by the thyroid gland?
Thyroid gland hormone and calcitonin
What cells produce calcitonin?
C cells in between thyroid follicles
What 2 hormones maintain blood calcium levels?
Calcitonin and parathyroid hormone
What does calcitonin do?
Helps prevent hypercalcemia by decreasing blood Ca levels by depositing excess in bone
What does parathyroid hormone (PTH) do?
Prevents hypocalcemia by causing kidneys to retain calcium, intestines to absorb calcium from food and withdraws it from bones
What happens in hyperthyroidism?
Thyroid gland is secreting too much TH, causing hyperactivity, increased metabolism, weight loss, PUPD, V/D, polyphagia and tachycardia.
What happens in hypothyroidism?
Thyroid gland isn’t secreting enough TH, causing decreased metabolism, weight loss, fur loss, cold intolerance, bradycardia, and lethargy
What happens in thyroid gland atrophy?
Normal thyroid tissue is replaced by fat
What happens in lymphocytic thyroiditis?
Immune system attacks thyroid cells
What are the 2 thyroid hormones?
T3 ( triiodothyronine) and T4 (thyroxine)
What is goiter?
Nonneoplastic noninflammatory enlargement of the thyroid gland caused by iodine deficiency. Caused by anterior pituitary producing more TSH which causes hyperplasia.
Which thyroid hormone is the active form?
T3
Where are the adrenal glands located?
Near the cranial ends of the kidneys
What are the inner and outer portions of the adrenal glands called?
The outer is the cortex and the inner is the medulla
The adrenal cortex develops from what tissue? What does is produce?
Glandular
Steroid hormones and sex hormones
What are the 3 glucocorticoid hormones? What do they influence?
Cortisol, cortisone, corticosterone
Influences hyperglycemia by influencing liver to convert proteins/lipids to glucose via gluconeogenesis, helps maintain BP and resist effects of stress.
Too much or too little glucocorticoid production is called what?
Cushing’s disease
Addison’s disease
Glucocorticoid drugs cause what adverse effects?
Immune suppression, delayed wound healing, catabolic effect, premature parturition, hyperglycemia, suppression of adrenal cortex, hyperadrenocorticism
What do mineralocorticoids do? What is the main hormone?
Regulate electrolyte level
Aldosterone
What is aldosterone’s target? What does it do?
Kidney.
Causes sodium ions to be reabsorbed into bloodstream in exchange for potassium and hydrogen to pass out in urine, maintaining a higher sodium to potassium ratio in blood.
The adrenal medulla develops from what tissue? What does it produce?
Nervous tissue
Epinephrine and norepinephrine
What controls hormone secretion of the adrenal medulla?
Nervous system
Most of the mass of the pancreas is made of which glandular tissue?
Exocrine
Pancreatic islets, or islets of Langerhans, make up which portion of the pancreas?
Endocrine
What are the 3 main pancreatic endocrine cells? What do they produce?
Alpha cells which produce glucagon
Beta cells which produce insulin
Delta cells which produce somatosin
What does somatosin do?
Inhibits insulin and glucagon, GH, and activity of GI tract
What does insulin do?
Causes glucose, amino acids and lipids in blood to be absorbed into body cells for energy. Lowers blood glucose.
What does glucagon do?
Causes hyperglycemia by stimulating liver cells to convert glycogen to glucose, and perform gluconeogenesis
What 2 hormones beside glucagon increases blood glucose?
GH and glucocorticoid hormone
