Physiology Exam 2 - Dr. Thomason Lectures

Endocrine, throid, adrenals, calcium reabsorption, growth hormone, and water regulation

What does the endocrine system regulate?

metabolism, growth/development, and mood

What is the system of glands that release hormones into circulation and has systemic effects?

endocrine system

What are the chemical messengers that are secreted from cglands and emptied into circulation?

hormones

T/F hormones are found in large concnetrations

FALSE

T/F Hormones alter the function of a target organ

TRUE

What are the endocrine focued glands?

hypothalamus, pituitary glands, thyroid gland, parathyroid gland, adrenal glands, and pancreas

What do endocrinopathies cause?

loss of control in multiple body systems

What is part of the diencephalon and forms the floor of the thrid ventricle in the brain?

hypothalamus

What part of the pituitary gland is glandular is separated into pas distalis/tuberalis/intermida?

anterior

Whar part of the pituitary gland is neural tissue?

posterior pituitary

What controls the release of pituitary hormones?

hypothalamus

What does the hypothalamus secretes both releasing hormones and inhibitor proteins to go to?

anterior pituitary

What kind of control is the posterior pituitary under?

neuronal control

What in the brain is a break in the BBB?

Hypothalamus

What type of capillaries does the hypoyhalamus have?

fenestrated

 

How do hormones get to the pituitary glands from the hypothalamus?

Median eminence

What connected the pituitary stalk to the hypothalamus?

Median eminence

What hormones are released by the hypothamus?

TRH, CRH, GHRH, GHIH. Somatostatin, GnRH, PIH

What hormones are released by the anterior pituitary?

ACTH, TSH, GH, prolactin, FSH, and LH

What type of hormones does the anterior pituitary release the most of?

Somatotropes

What hormones does the posterior pituitary release?

ADH and oxytocin

Where do axons terminate in the pituitary gland?

posterior

What hormone regulates free water excretion for the kidneys and blood pressure?

ADH/vasopressin

What hormone helps with milk expression and birth?

oxytocin

What thyroid hormone is most abundant?

T4 (thyroxine)

What are the two thyroid hormones?

T3 and t4

What is t3?

triiodothyronine

What is t4?

thyroxine

How many iodine molecules does thyroxine have?

4

How many iodine molecules does triiodothyronine have?

3

What are the functions of thryoid hormones?

increase metabolic rate

What is the large bi-lobed gland in the cervical neck?

thyroid

What are the glands on the thyroid that have something to do with calcium metabolism?

Parathyroid glands

How many parathyroid glands are there in the body?

4

What gland is responsible for calcium regulation?

parathryoid glands

What are the two types of cells in the thryoid?

follicular and parafollicular cells (thyrocytes and C cells)

What cells in the thyroid is a single layer of cuboidal/columnar cells that surround a lumen filled with colloid?

Follicular cells or thyrocytes

What cells in the thyroid secrete calcitonin thus regulating calcium?

Parafollicular cells (C cells)

What is the process of making T3/T4?

Thyroglobulin synthesis

What is organification of thryoglobin synthesis?

adding I to tyrosine

What must you have to make T3/T4?

Thyroglobulin and iodine

What organ in the body uses iodine?

thyroid

Where is thyroglobulin synthesized?

follicular cells in the thyroid

Where is thryogloblin stored?

colloid (follciluar lumen)

T/F thyroglobulin are huge` molecules

TRUE

Where is iodine absorbed?

GI tract

Where does iodine uptake occur?

Thryoid gland

What type of transport is used for uptake of iodine in the thyroid?

TSH-depened active transport

What process binds iodine to thyroglobulin?

organification

What molecule results when thyroglobulin binds to 1 iodine molecules?

Monoiodotyrosine (MIT)

What molecule results when thyroglobulin binds to 2 iodine molecules?

Diiodotyrosine

What is the resulting molecules with DIT couples to DIT?

T4

What is the resulting molecules with DIT couples to MIT?

T3

What does thyroid peroxidase do (TP)?

iodine oxidation, organification, coupling

Where does the process of t3/t4 synthesis occur?

in colloid

What thyroid hormone is most active, potent and fast?

T3

Where is the majority of t3 made?

tissues via de-iodination

What are the binding proteins that allow for T3 and T4 transport?

thyroxine-binding globulin and albumin

What determines the half-life of T3 and T4?

binding affinity

What is the active form of T3 and T4?

free

How is the majority of T3 and T4 found in the body?

protein-bound

Do drugs that alter protein binding effect FREE T4 concentration?

NO

What happens to protein-bound T4 when drugs that bind to proteins are given?

decrease

What happens to protein-bound T4 when drugs that increase binding proteins are given?

increase

What are examples of drugs that bind to proteins?

Glucocorticoids and androgens

What are examples of drugs that increase binding proteins?

estrogen-containing products

What type of drugs increase TBG?

estrogen-containting products

What type of drugs decreases the protein-bound fraction?

glucocorticoids and androgens

What thyroid hormones has no biological activity?

reverse T3

Are thyroid hormones lipophilic or hydrophilic?

lipophilic

What issues are NOT affected by thyroid hormones?

Lungs, sex organs, retinas, lymph nodes, and spleen

What do thyroid hormones regulate cia gene expression?

enzymes and proteins

What do thyroid hormones do to the metabolic rate?

increase it

What type of effects do thyroid hormones have?

catabolic

What in the plasma does the catabolic effects of thyroid hormones reduce?

plasma cholesterol levels

What do thryorid hormones do to gastrointestinal motility?

increased

What are the cardiovascular effects of thyroid hormones?

simulation of beta-adreergic receptors, increase glomerular filtration rate, and stimulates erythropoiesis

What are the neuromuscular effects of thyroid hormones?

increase mental alertness and increase response to GH

What is released from the hypothalamus to eventually stimulate thyroid hormone production?

thyrotropin releasing hormone

What does thyrotropin releasing hormone from the hypothalamus cause the release of?

TSH

What releases thyrotropin releasing hormone?

hypothalamus

What releases TSH?

pituitary gland

What does the release of TSH from the pituitary cause the release of?

T3 and T4

What does TSH promote?

Iodide trapping, colloid endocytosis, and thyroid cell hypertrophy

An increase in what hormones causes a negative feedback loop on the thyroid axis?

FREE T3 and T4

What does an increase of FREE T2 and T4 cause?

a decrease in TSH

An animal is presented with lethargy, decreased appetite, extreme weight gain, and has severe hypercholesterolemia. What could this animal have?

hypothyroidism

T/F Thyroid hormone stimulate cholesterol metabolism

TRUE

An animal is presented with weight loss, decreases sleep, voracious appetite, vomiting, hyperactive, irritable, decreased muscle mass, moderate erythrocytosis, and mild increase in ALT. What is a possible cause?

hyperthyroidism

What is the treatment for hypothyroidism?

levothyroxine BID

What is the treatment for hyperthyroisim?

methimazole

What drug is a thyroid peroxidase inhibitor and inhibits organification coupling and can be used to treat hyperthyroidism?

methimazole

What is it called when one has a greatly enlarged thyroid (hypertrophy)?

goiter

Where does steroid hormone synthesis occur?

adrenal cortex

What axis regulates steroid hormone sysntheis?

HPA Axis

What are the two hormones produced by either the RAAS and the HPA axis via the adrenal cortex?

cortisol and aldosterone

What hormone stimulates gluconeogenesis and is an anti-inflammatory?

cortisol

What hormone regulates blood volume as well as potassium and sodium?

aldosterone

What pathway produces aldosterone from the adrenal cortex?

aldosterone

What nervous system does the adrenal medulla regulate?

sympathetic nervous system