Endocrine system Flashcards
4 mechanisms by which cells communicate
Neurotransmitters (nervous system) Hormones (released into blood stream or other fluids) Gap junctions (direct communication between cells) Paracrines/Local hormones (into tissue, dont last long in blood)
Mediator Molecules- Nervous system V Endocrine system
N: Neurotransmitters E:Hormones
Speed and persistence of response: Nervous system V Endocrine system
N: Quick response, dont last long E: Slower response, last longer
Site of mediator action: Nervous system V Endocrine system
N:Localized, directly into cell E: Wide spread effect
Types of Target cells: Nervous system V Endocrine system
N:nerve & muscle cells E: all body cells
Components of endocrine system
endocrine glands, hormones, target cells
Endocrine system includes
endocrine glands, hormone producing cells in organs such as brain, heart and small intestine
Exocrine Glands (4) things
1) secretes into ducts 2)local effect 3)extracellular effect 4) includes salivary and sweat glands
Endocrine Glands (4) things
1) ductless 2)secrete into capillaries 3) wide spread effect 4)intracellular effect
Strictly endo glands
thyroid, parathyroid, adrenal, pineal, pituitary
endo and exo glands
pancrease, ovary and testes, hypothalmus
Tropic Hormone
When one hormone triggers another cell to make other hormones.
When hormones bind with receptor cells (5)
1)Alteration of plasma membrane permeability/potential (open or close ion channels) 2)stimulates synthesis of proteins or enzymes within target cells 3) activates/deactivates enzymes 4)induces secretory activity 5)stimualtes mitosis
chemistry of hormone determines
how it travels through the bloodstream and ho wit interacts with target cells.
Steroid
Fat soluble: sex steroids, adrenocortical hormones
different types of hormones
Steroids, peptides and glycoproteins, monoamines
Fat soluble hormones
Steroids
Water soluble hormones
Peptides, glycoproteins, monoamines
Water soluble hormones must
bind or travel through a receptor on the surface of the cell- fat soluble cells can pass through
Types of receptor binding mechanisms
1) plasma membrane receptors 2)intracellular receptors
Plasma membrane receptors are for
water soluble hormones (usually work through 2nd messenger receptor)
Intracellular Receptors are for
lipid soluble hormones
Lipid soluble requires…..to get through blood stream
transport protein
water soluble hormones must ……to get into cell
bind to receptors on the exterior surface of the target cell..activating a motor protein (G protein)
How a target cell responds to a hormone is based on 3
1)hormones concentration in blood 2)# of hormone receptors on target cell 3)influences exerted by other hormones - synergistic or antagonistic effect
Synergistic effect
When certain hormones work more effectively when a second hormone is around to assist them
Antagonistic effect
When certain hormones oppose the action of others
Up-regulation
increasing the # of receptors on the surface of a cell
Down-regulation
Decrease # of receptors to decrease response. Ex: building up a tolerance ex:insulin resistance.
Hormone clearance
1) hormone signals must be turned off
MCR of hormone
Metabolic Clearance Rate
Half-life
time required to clear 50% of hormone
How are hormones cleared 3 steps
1)hormone signals are turned off 2)taken up and degraded by liver and kidney 3)excreted in bile or urine
Humoral stimulus
Refers to fluids- endocrine gland responds directly to blood chemistry: EX:hypocalcimia
Neural Stimulus
neuron sends action potential to endocrine cell to secret hormone EX:sympathetic neurosystem to adrenal medula
Hormonal Stimulus
One hormone get secreted to trigger other endocrine organs to secret other hormones
3 ways endocrine glands can be stimulated to secrete hormones
1) Humoral stiumulus 2) neural stimulus 3)hormonal stiumulus
Most hormone regulation is achieved via
negative feedback
Pituitary Gland is also known as the
Hypophysis
Pituitary gland is attached to the hypothalmus by
a stalk called infudibulum
The pituitary gland sits in the
Sella turcica of the sphenoid bone
The pituitary gland is seperated into two glands
1) Anterior pituitary/adenohypophysis 2)Posterior pituitary//Neurohypophysis
The Neurohypophysis is made of
neurons
The posterior/neurohypophysis originates from
Ectoderm
The anterior/adenohypophysis orginates from
endoderm
The hypothalamus stimulates the AP using
Hormones
the hypothalamus stimulates the PP using
nerve impulses/action potentials
AP has a ….. system
hypophyseal portal system
PP has a ………tract- axon of neurons
hypothalamo-hypophyseal
the AP secrets which hormones (7)
FSH, LH, TSH, ACTH, GH, PRL
the PP secrets which hormones (2)
Anti-Diuretic Hormone/Oxytocin
Nuclei that trigger the posterior pituatary
1)paraventricular nucleus 2)supraoptic nucleus
Neurosecretory cells
Cell sproduced in hypothalamus transported down axons in the secretory vesicles. secrete neurotransmitter into the blood
ADH responds to
osmotic pressure (dehydration)
ADH/vasopressin
Anti-Diuretic Hormone: conserves body water by decreasing urine volume and water loss through prespiration. Raises blood pressure by constricting arterioles.
Oxytocin stimulation
Responds to baby pressing against uterus and baby suckling - milk release
Anti-Diuretic Hormone Stimulation
elevated blood osmotic pressure, dehydration,
Words releasing or inhibiting trigger that it is being released from the EX:Thyrotropin-releasing hormone
hypothalamus
Thyrotropin-releasing hormone stimulates the release of
Thyroid stimulating hormone/thyrotropin
What hormone does the thyroid hormone make
T3 and T4
3 Tropic hormones
Gonadotropins (FSH and LH), TSH, ACTH
FSH
Follicle stiumlating Hormone
LH
Luteinizing Hormone
ACTH
Adreno-cortico-tropic Hormone/Corticotropin
What part of the adrenals does ACTH target?
the cortex
Non Tropic AP Hormones
PRL and GH
PRL
Prolactin (targets mammary glands)
GH
Growth Hormone/Somatotropin
Tropic Pathways include which organs
Thyroid, testis, ovaries and adrenal cortex
oogenesis
the development of eggs
spermatogenesis
when the testes produce sperm
Growth Hormone is insulin or anti insulin
antiinsulin- growth hormone has a hyperglycemic effect
Hypothalmus Anterior lobe is controled by
Hormones
Hypothalmus Posterior lobe is controlled by
Neuroendocrine reflexes
which is the largest endocrine organ
thyroid
Thyroid follicle is made up of
cuboidal cells
Colloid
precursor of thyroid hormone/where the thyroid hormones are produced
Follicular cells are stimulated by …and produce…
TSH and T3 and T4
Parafollicular (C) cells
produce calcitonin
calcitonin
decreases blood calcium
T3 and T4 are synthesized in how many steps
8
BLANK + BLANK = Thyroid hormone
TGB thyroglobulin + Iodine = T3 + T4
2 hormones released by thyroid
thyroid hormone (T3 and T4) and calcitonin
Parathyroid hormones are secreted in times of
low blood calcium
parathyroid hormones are located
on the back of the thyroid
PTH
Parathormone
3 thyroid hormones that work together to regulate calcium homeostasis, increase
Calcitonin, PTH, calcitriol
Calcitriol
works to stimulate calcium into the blood - for hypocalcemia
Two regions of adrenal glands
Cortex and medulla
3 regions of the adrenal glands (outside to in)
zona glomerulosa, zona fasciculata, zona reticularis
Which adrenal zone produces cortisol
Zona fasciculata
Corticosteroids
steroid based hormones
zona glomerulosa releases
aldosterone, when blood pressure is low, tells kidneys to retain salt therefore water, increasing blood pressure
Cortisol stimulates
fat + protein catabolism, gluconeogenesis and release of fatty acids and glucose into blood = anti-insulin - hydrocortisone= antinflammatory
gluconeogenesis
new glucose formation
zona reticularis
produces androgen / estrogen etc. Sex hormones.
adrenal medula is apart of which nervous system
autonomic, more specifically sympathetic
Pancrease, endo or exocrine?
Both but primarily exocrine
Islets of langerhans
alpha and beta cells
which cells in the pancreas produce insulin
beta cells
Alpha cells produce
glucagon
Somatostatin (delta cells)
regulate beta and alpha cells
glucagon V insulin
glucagon raises glucose levels(hyperglycemic), insulin lowers glucose levels (hypoglycemic)
Insulin is unique because
only hormone with hypoglycemic effect
Pineal gland is located
back of thalmus/epithalmus
Thymus Gland is located
above your heart
Pineal gland produces
serotonin by day which converts to melatonin at night.
Pineal gland is associated with
indirectly receiving information from retinas for our inner clock/ seasons, length of days
Thymus secretes
thymosin that regulates the development and later activation of T-Lympohcytes = immune system “where t cells mature and get their training”
What does heart release with an increase BP
ANP=atrial natriuretic peptide
Acromegaly
Hypersecretion of growth hormone after skeletal maturity
lack of ADH=
diabetes insipidus - increase urination losing fluid and electrolytes
SIADH
not urinating enough
creatinism
infant hypothyroidism
myxedema
adult hypothyroidism
Endemic goiter
enlarged thyroid gland, lack of dietary iodine - when the TSH comes to the thyroid, colloid is built up but without iodine we build build hormone
Graves Disease
automimmune hyperthyroid toxic goiter- antibodies mimic TSH and bind to TSH receptors and massively produces thyroid hormone. Dont respond to negative feedback
pathomnemonics
symptoms that are undeniable
exothalmos
graves disease evidence, bulging of the eyes
Cushing syndrom
hypercortisolism
Cushing syndrome with ACTH secretion =
cushing diseases
Addisons disease
hypocorticolism
osmotic diuresis
too much glucose in the blood, increase urination
type 1 diabetes
autoimmune destruction of B cells
type 2 diabetes
insulin resistance
