Endocrine System Flashcards
How does the endocrine system work with the nervous system?
coordinates and integrates activity of body cells: release of chemicals, share chemical messengers (Epi and NE), and preserve homeostasis
What are the basics of the endocrine system?
deals with: hormones, transmission via circulatory system, long-term effect, and slow to respond
What are the basics of the nervous system?
deals with: neurotransmitters, transmission vis synaptic cleft, short-term, quick response
What is the difference between exocrine and endocrine systems
Exocrine: non-hormonal substances, ducts, substance to membrane surface
Endocrine: hormones, no ducts, released into tissue
What are the major types of endocrine glands?
pituitary, thyroid, PTH, adrenal, pineal, hypo, pancreas, gonads
What are hormones?
chemicals released by cell, organ, glands –> activates target cells with specific receptors
What are the mechanisms of hormone action?
upon binding –> plasma membrane permeability change by opening/closing, stimulates enzyme synthesis + activate/deactivation, induces secretion + stimulates mitosis
What are the two classes of hormones?
amino acid based: most hormones and include T4 and ACTH
Steroids - created from lipids (cholesterol): test (androgen), estrogen, progesterone, cortisol (glucocorticoid) and aldosterone (mineralcorticoids)
What is the difference between amino acid and lipid based hormones?
- Amino acid + water soluble
o All amino acid except thyroid
o Act on plasma membrane receptors of
target
o Involves G protein - Lipid soluble + hydrophobic
o Steroids and thyroid
o Act on intracellular (carrier proteins)
o Directly activate genes
What controls hormone release?
- Negative feedback
o Hormone rise + causes on target
organ inhibit hormone release - Nervous system can override to maintain homeostasis by overriding normal endocrine controls
- Humoral Stimulus – caused by
alteration of ion/nutrient levels
o Ions and nutrients in blood (
parathyroid and thyroid)
o Certain tissues have certain receptors - Neural Stimulus – neural input
o Action potentials signal adrenal medulla to release adrenaline and NE - Hormonal Stimulus – caused by another hormone
o Hypothalamus –>Anterior pituitary secretes hormones that stimulates thyroid –>adrenal cortex –> gonads
What makes up the Pituitary gland?
- Anterior + posterior
- Connected to hypothalamus through infundibulum
What does the ant pituitary gland do?
- “master endocrine gland” – synthesizes and releases 6 hormones
- Four tropic – regulate secretory activity
o Thyroid stimulating (TSH)yyfc
o Adrenocorticotropic (ACTH)
o Follicle-stimulating (FSH)
o Luteinizing (LH) - Non-tropic
o Growth hormone (GH)
o Prolactin (PRL)
What is the Hypothalamic Pituitary Relationship: Posterior Pituitary?
- Neural connection with hypo via hypothalamic-hypophyseal tract
- Hypo secretes two hormones that are stored and released here
o Oxytocin
Stimulates muscles for childbirth
Milk reflex
Social bonding
o Antidiuretic hormone (ADH)
Prevents dehydration with water
balance
Targets kidney tubules which respond
from water from urine back into
bloodstream
Inhibited by Alc
What’s the difference between Thyroid Stimulating Hormone and Adrenocorticotropic hormone?
TSH: HPT axis – hypo –>anterior pit–>thyroid–> target cells
Adrenocorticotropic: HPA axis – hypo –> ant pit –> adrenal cortex –> target cells
What happens with an ADH homeostatic imbalance?
- Diabetes insipidus – ADH deficiency and kidneys can respond to ADH
o Intense thirst and dilated urine - Syndrome of inappropriate ADH secretion – hypersecretion of ADH
o Retention of fluid, brain edema
What is the Hypothalamic Pituitary relationship: anterior pituitary?
- Anterior – vascular vis hypophyseal portal system
o GnRH
o GHRH
o GHIH (inhibiting hormone)
What do Gonadotropins (FSH and LH) do?
- Follicle stimulation and luteinizing
- Stimulates sperm/egg production (FSH)
- Stimulates production of gonadal hormones (LH)
- HPG axis – hyp ant pit Gonads produce gonadal hormones + gametes
What is prolactin?
stims milk, estrogen + nursing = stim, dopamine is inhibited
What are the 6 hormones of the ant pit?
FLAT PIG - FSH + LH + ACTH + TSH - Prolactin and GH
Water-soluble hormones usually involve what?
G proteins and a second messenger system
ADH and oxytocin are produced in the _____ and released from ____
hypo and posterior pituitary
What hormones are released by the anterior pituitary?
Prolactin, ACTH, LH, GH, TSH, FSH
Which hormone stimulates thyroid to release T4 and T3?
TSH
What is associated with hypothyroidism in infants?
cretinism
When BP is low, what hormone is released?
Aldosterone
What is one of the functions of cortisol?
promote gluconeogenesis if blood glucose is low
