PHYL 142 Exam 1: Endocrinology

endocrine

"endo-" inside; inner secretion into bloodstream

exocrine

"exo-": outside; outer secretion into epithelium

triglycerides

3 fatty acid + 1 glycerol molecule major for of fatty acid and energy stored primarily stored in adipose tissue

negative feedback controls hormone levels

Hormone A accumulates Hormone B increases Increased B slows production of A Production of A drops off Degradation and clearance takes over and lowers A Lack of A leads to drop in B lack of B eases up on inhabitation if A Hormone A can accumulate again

Nervous, endocrine, and anatomical relation to the hypothalamus

Hypothalamus contains both brain centers and endocrine tissue, and found inferior to the thalamus Hypothalamus is superior to the pituitary gland, and is connected to it by the slender, funnel-shaped structure called the infundibulum Acts as an endocrine organ, secretes regulatory hormones, contains autonomic center

HPT axis

TRH. TSH, T3, and T4 TRH - from the hypothalamus promotes the pituitary's secretion of TSH TSH - regulate both the synthesis and release of thyroid hormone T3 - Triiodothyronine contains 3 iodine atoms T4 - Thyroxine contains 4 iodine atoms

anterior lobe hormones produced

TSH, ACTH, FSH, luteinizing hormones, growth hormone, prolactin

hormone

a chemical messenger that is secreted by one cell and travels through the bloodstream to affect the activities of cells in other parts of the body

negative feedback definition

a creative mechanism that opposes or negates a variation from normal limits

positive feedback definition

a mechanism that increases a deviation from normal limits after an initial stimulus hormone leads to more release of the same molecule

pars intermedia

a narrow band bordering the posterior lobe

glucagon (catabolic) is released by

alpha cells stimulates breakdown of glycogen in skeletal muscle and liver cells stimulates breakdown of triglycerides in adipose tissue

amines

amines catecholamines tryptamine thyroid monoamines

posterior lobe hormones produced

antidiuretic hormone/vasopressin, oxytocin

random glucose test

blood glucose without fasting

lipolysis

catabolism of lipids as a source of energy lipids are broken down into pieces that can be converted into pyruvate or channeled into the citric and acid cycle

hormone that stimulates gluconeogenesis

cortisol effects: glucose metabolism and blood glucose fat metabolism suppresses immune function catabolic steroid

circadian rhythm

daily changes in physiological processes that follow a regular day-night pattern

hypoglycemia

deficiency of glucose in the bloodstream

monoamines

derived from single amino acids thyroid hormone is not a monoamine

ligand receptor interactions

determines if a cell can respond to a hormone determine how cells responds to a horomone

catecholamines

dopamine norepinephrine epinephrine

hyperglycemia

excess of glucose in bloodstream, often associated with diabetes mellitus

fasting for blood glucose testing

fasting - no eating/drinking for > 8 hours, water is okay

growth hormone

growth protein synthesis, lipid mobilization and catabolism

secondary endocrine organs

heart thymus adipose tissue digestive tract kidneys gonads

negative feedback occurs in these axis and affect what horomone

hormone 2 is responsible for negative feedback negative feedback from these target organ hormones controls the rate at which the hypothalamus secretes regulatory hormones

negative feedback

hormone A leads to production of B B inhibits Hormone A production much more common that positive feedback

endocrine system

hormones produced by endocrine cells reach almost every cell in the body effects of hormones on their target may be slow to appear, but they typically last for days

peptide

hydrophilic peptide bond link amino acids carboxyl and amino group chains of amino acids stored in vesicles for later secretion the largest group of hormones includes all hormones from pituitary

anterior lobe

hypophyseal portal system-network of vessels that carries blood from capillaries in the hypothalamus to capillaries in the anterior lobe of the pituitary gland

primary endocrine organs

hypothalamus pituitary gland thyroid gland adrenal gland pancreas pineal parathyroid

acute stress response: sympathetic vs endocrine control

hypothalamus contains autonomic centers that exert direct neural control over the endocrine cells of the adrenal medulla sympathetic division is activated, the adrenal medulla releases the hormones epinephrine

hypothalamic-pituitary-adrenal axis

hypothalamus>corticotropin release hormone>pituitary adrenocorticotropic hormone>adrenal glands

hypothalamic-pituitary-gonadal axis

hypothalamus>gonadotropin releasing hormone>pituitary>follicle-stimulating hormone and luteinizing hormone>gonads

HPT axis organs/tissues

hypothalamus>pituitary>thyroid

hypothalamic-pituitary-thyroid axis

hypothalamus>thyrotropin releasing hormone>pituitary>thyroid stimulating hormone>thyroid

hypoxia

insufficient oxygen in blood or tissue

Type 1 Diabetes

insulin dependent pancreatic beta cells don't produce enough insulin T effector cells start to attack beta cells

Type 2 Diabetes

insulin resistant insulin still produced negative feedback due to constant high insulin signaling is one possible cause of insulin resistance

oxytocin

labor contractions, milk ejection

pars distalis

largest and most anterior portion of the pituitary gland

pituitary gland location

lies nestled within the sella turica, a depression in the sphenoid bone

general class bind to intracellular receptors effects inside the cell differ from extracellular receptors

lipid-soluble hormones freely diffuse across the plasma membrane steroid receptors are located inside the cell hormone-receptor interactions regulate genes

hydrophobic hormones are transported into blood

lipids are hydrophobic 92% of your body is water colloid - solution of very large organic molecules blood is colloid

thyroid hormone

made from two tyrosine amino acids iodination

luteinizing hormone

male-secretion of testosterone female-ovulation, formaton of corpus luteum, secretion of progesterone

follicle-stimulating hormone

male-stimuation of sperm maturation female-secretion of estrogen, follicle development

adrenal cortex hormones produced

mineralocorticoids, primarily aldosterone glucocorticoids (cortisol, corticosterone, and cortisone)

ligand

molecule that minds to a protein

general class of hormones

monoamines, peptides, and lipid derivatives

pineal gland

nervous tissue in the posterior portion of the roof of the diencephalon

autonomic nervous system

neurons use action potentials and neurotransmitters to control specific cells or group of cells allows synaptic communication to provide crisis management in situations requiring split-second responses; commands are very specific and relatively short-live

posterior lobe hormone production

neurosecretion, neurons directly secrete hormones into bloodstream

posterior lobe

no portal system, inferior hypophyseal artery delivers blood to it, and the hypophyseal veins carry the blood and hormones away

hemoglobin A1c

normal A1c red blood cells contain hemoglobin glucose can attach to hemoglobin RBSc live about 3 months in the body

insulin (anabolic) is released by

pancreatic beta cells stimulates glucose to support growth and build carbohydrates and lipid reserves

general class of hormones that bind to extracellular receptor

peptide and monoamine hormones are typically hydrophilic peptide and monoamine receptors are typically on the plasma membrane's outer surface

erythropoietin

peptide hormone released by the kidneys response to low oxygen levels in kidney tissues\stimulates red bone marrow to produce RBCs, increase in the number of RBCs elevate blood volume

prolactin

production of milk

receptor

protein that binds to a ligand

antidiuretic hormone/vasopressin

reabsorption of water, elevation of blood volume and pressure

similarities between autonomic and endocrine

release of chemicals that bind to specific receptors on their target cells regulated mainly by negative feedback control mechanisms preserve homeostasis by coordinating and regulating the activities of other cells, tissues, organs, and systems

anterior lobe hormone production

releasing hormones, inhibiting hormones, or some combination of the two may control an endocrine cell in the anterior lobe

adrenal gland hormones produced

secrete epinephrine and NE in response to sympathetic activity

melatonin

secreted by the pineal gland important for circadian rhythm

adrencorticotropic hormone

secretion of glucocorticoids

tryptamine

serotonin melatonin

higher GI

sharp increase in blood glucose

lower GI

smaller increase in blood glucose

glucagon

stimulates production of glucose in liver

thyroid stimulating hormone

stimulates secretion of thyroid hormones affects almost every cell in the body important for metabolism and cell function

melanocyte stimulating hormone

stimulates the melanocytes of the skin, increasing their production of melanin, a brown, black, or yellow-brown pigment

adrenal gland anatomy

superficial to deep capsule>cortex>medulla

gluconeogenisis

synthesis of glucose from noncarbohydrate precursors creating new glucose

acute stress response: organ and tissues

the amygdala sends signals to the hypothalamus

endocrine communication (hormone transport)

transmission through the bloodstream chemical mediator is the hormones target cells are primary in other tissues and organs and must have appropriate receptors

trophic hormone

turn on endocrine glands or support the function of other organs

pars intermedia

virtually non function, and the circulating blood usually does not contain melanocyte-stimulating hormone

pars tuberalis

wraps around the adjacent portion of the infundibulum

adrenal gland cortex

zona glomerulosa - aldosterone production zone fasciculata-glucocorticoid/cortisol production zona reticularis-androgen production (once in bloodstreem, some of the androgens from the zona reticularis are converted to estrogens androgens>aromatase>estrogens

effects of blood sugar/glucose

↑ glucose use and ATP production ↑ glycogen formation ↑ amino acid absorption and protein synthesis ↑ triglyceride formation in adipose tissue

hypothyroidism

↓ ATP production ↓ heat Weight gain Bradycardia - slow heart rate Depression

normal fasting range

70-110 mg/dL

hyperthyroidism

Grave's Disease Goiter - enlarged thyroid Tachycardia - rapid heart beat Weight loss Thinning hair Proptosis - bulging eyes