L11- Endocrine Flashcards
Endocrine
“Enter”
Go into the blood
Exocrine
“Exit”
Secrete outside
What organ/ structure has Both exocrine and endocrine
Pancreas
Hormone
Chemical made by endocrine glands
- released into the blood
- acts as messenger molecule
Target cell
Distant cell upon which hormones act
- contain receptors (specificity)
Receptor
Protein molecules on/ in target cells
- binds hormones w/ specificity
- produces response in target cell
Similarities of the Nervous system and endocrine system
- Function = communication systems ➡️ control body processes
- NS = hard wired
- ES = wireless
- Use chemical messenger molecules
- NS = neurotransmitters
- ES = hormones
- Require receptors
- NS = synapse
- ES = target cells
- Require mechanisms to turn off
- NS = degrades ➡️ reuptake
- ES = removed by target organ or liver
Nervous system vs endocrine system differences
- Messenger molecule released
- NS = axon release Nt ➡️ synaptic cleft
- ES = endocrine cells release hormones into blood
- Distance to target cells
-NS = target cell adjacent to axon terminal- ES = target cell far away from glands
- Speed
- NS = fast, short acting
- ES = slow, longer acting
- Pathways
- NS = hard wired (don’t fuse)
- ES = diffuse
What organs are solely endocrine organs?
Pituitary, thyroid, parathyroid, adrenal gland
How is the endocrine system regulated?
- Control amount of hormone secreted
- Regulate number of receptors in the membrane
Humoral control
Direct feedback by chemicals in the blood
Hormonal control
Stimulates or inhibits hormone secretion
- hormones regulating themselves
Downstream regulation __________ and upstream regulation ____________
Stimulates (+), inhibits (-)
Neural control
Neuroendocrine reflex
- contractions to push baby out during birth
How can you regulate the number of receptors on a membrane?
Up regulation = low hormone levels ➡️ synthesize more receptors
Down regulation = high hormone levels ➡️ remove/ recycle receptors
What are the three chemical classifications of hormones?
Steroids, protein, amine
Steroid hormone
Made from cholesterol
Protein hormone
Made from amino acids
Amine hormone
Made from tyrosine
What hormones are steroids?
Aldosterone, cortisol = adrenal cortex
Estrogen, progesterone, testosterone = gonads
What hormones are protein hormones? And where are they secreted
Pancreas = insulin & glucagon
Pituitary gland = all (growth, oxytocin, anti diuretic)
Hypothalamus = all hormones
What hormones are amine hormones? And where are they found
Thyroid gland = thyroid hormone (thyroxine)
- acts as steroid
Adrenal medulla = epinephrine
- acts as protein
Where polar hormone receptors found?
Receptor on plasma membrane
Where are Nonpolar hormone receptors located?
Receptor in cytoplasm or nucleus
Mechanism of Nonpolar hormones
- Bound to carrier protein in blood; released and defuses across membrane
- Bind to receptors in cytoplasm or nucleus
- Binds to and turns on gene
- DNA transcription
- Protein synthesis
- Protein product produces hormone response in cell
Mechanism of thyroid hormone
- T4 (inactive form) carried in blood bound to carrier protein; acts as hormone reservoir
- Converted to T3 (active form) in cytoplasm
- Cell response ➡️ increase cell metabolism
Mechanism for polar hormones
- REQUIRE Signal Transduction ➡️ can’t cross membrane (receptor on membrane)
- need 2nd messenger
1. Adenylate cyclase = cAMP
2. Phospholipase = ca2+
3. tyrosine kinase = varies
Axis
Series of glands that use hormones to signal each other in sequence
Tropic
Influencing the activity of another gland
What organs are part of the hypothalamic pituitary adrenal axis?
Hypothalamus, anterior pituitary, adrenal cortex
What a hormones are involved in the hypothalamic pituitary adrenal axis
CRH - Corticotropin releasing hormone
ACTH - Adrenocorticotropic hormone
Cortisol
Anterior pituitary
Separate endocrine gland
Posterior pituitary
Neural extension of hypothalamus; cells = neuroendocrine or neurosecretory
What is the hypothalamus control on the posterior pituitary
Neuroendocrine cells in hypothalamus make hormones which get stored in the axon terminals in the posterior pituitary
What are the hormones released from the posterior pituitary?
Oxytocin and ADH (anti diuretic hormone)
What is oxytocin’s function
Stimulates smooth muscle in the uterus and Brest to contract
What is the function of Antidieretic (ADH)?
Stimulates water reabsorption in kidneys; vasoconstriction
Hypothalamus control on the anterior pituitary
Hormones released into capillary bed then it travels down to anterior pituitary
What hormones are released from the anterior pituitary?
- prolactin (PRL)
- Growth hormone (GH)
- thyroid stimulating hormone (TSH)
- Adrenocorticotropic Hormone (ACTH)
- Leutinizing hormone (LH) & Follicle stimulating hormone (FSH)
What anterior pituitary hormones go to their final effector?
PRL - Prolaction ➡️ mammary glands
GH - Growth hormone ➡️ bones, muscle, fat
What anterior pituitary hormones go to a target tissue and release another hormone?
TSH - Thyroid stimulating hormone
ACTH - Adrenocorticotropic Hormone
LH- Leutinizing hormone & FSH - Follicle stimulating hormone
NFL of thyroid gland
Thyroid gland negatively feedbacks on hypothalamus and anterior pituitary when thyroid hormone is high within the blood
What is the consequence of surgically removing the thyroid gland?
- no negative feedback
- increase thyroid stimulating hormone (TSH) & Thyroid releasing hormone (TRH)
What is the thyroid hormones function
Increase metabolic rate in target cells
NFL of cortisol
Cortisol negatively feedbacks on the hypothalamus & anterior pituitary when cortisol levels high in the blood
What is the consequence of damage to the adrenal gland?
- decrease of negative feedback
- increase in cortotropic releasing hormone (CRH) & Adrenocorticotropic hormone (ACTH)
Cortisols function.
Promote release of fuels (glucose, lipids) in target cells
What hormones are released from the adrenal gland?
Epinephrine, cortisol and aldosterone
Acute stress (sudden emergencies) releases what hormone from the adrenal gland
Epinephrine - activating fight/flight
- releases from adrenal medulla
Chronic stress (prolonged exercise, cold, illness) releases what hormones
Cortisol - breaks down stored fuels (increasing blood fuel levels)
Aldosterone - sodium retention in kidneys
Regulation of the thyroid gland
Hormonal = negative feedback
What are the two forms being secreted into the blood by thyroid gland?
T4 - thyroxine
T3- triiodothyronine (active form)
What hormones are released from the thyroid gland?
Thyroid hormone & calcitonin
Calcitonin function, regulation stimulus?
Function: Decreases blood ca2+
Regulation: humoral
Stimulus: elevated ca2+ in blood
Parathyroid releases what hormones
Parathyroid hormone
Parathyroid hormone function
Increase blood ca2+
What are the two hormones that regulate calcium in the blood?
Calcitonin - decreases ca2+
Parathyroid hormone - increases ca2+
What are the three general disorder causes?
- Hyposecretion of hormones
- below or low amount - Hypersecretion of hormones
- above or too much - Lack of functional hormone receptor
Iodine deficiency goiter cause
Insufficient amount of dietary iodine
Effect of iodine deficiency goiter
- decreases TH causing decrease of NFL ➡️ high TRH & TSH
- ELEVATED TSH = ABNORMAL GROWTH OF THYROID GLAND
What are the symptoms of an iodine deficiency goiter
- low metabolic rate
- weight gain
- cold sensitivity
- lethargy (tired)
Hashimoto disease is caused by
Autoimmunity to thyroid gland - breaks down the thyroid gland
What is the effect of Hashimoto disease
Damaged thyroid gland = decrease TH
- decreased TH = decrease NFL= High TSH & TRH
What is the treatment for Hashimoto disease?
Give thyroid hormone
Graved disease cause
Autoimmunity to TSH receptor of thyroid gland
What is the effect of Graves’ disease
Thyroid gland always on = increase TH = increase in NFL = decrease in TRH & TSH
What are the symptoms of Graves’ disease? And how is it treated?
Symptoms :
- high metabolic rate
- weight loss
- heat sensitivity
Anxious
Insomnia
- Bulging eyes
Treatment :
Drug to decrease thyroid hormone production
Sensory transduction occurs in __________
Sensory receptors
Sensory transduction function
Converts sensation into action potentials
Synaptic transmission occurs _________
At synapses
Synaptic transmission function
Communication b/w two cells
Signal transduction occurs in _______
Target cells
Signal transduction function
Convert a ligand binding event into a cell response
