endocrine system Flashcards
Endocrine system
hormone system, regulates metabolic activites
endocrine glands?
secrete hormones into body fluids- thyroid, adrenal, pineal glands
hormones
chemical signaling messengers that coordinate different functions, travel slower than nerve impulses, but lead to longer term stimulations
when are hormones released?
presence of other hormones, humoral stimulation(ion/nutrient in the blood), autonomic neural stimulation
hormonal level is regulated by what system, negative or positive?
negative feedback system
classes of hormones?
amino acid-derived, peptides, lipid-derived
amino acid-derivatives hormones
synthesized from amino acids.
they include:
catecholamine(epinephrine, norpinehrine, dopamine) and melatonin
peptiedes
chains of amino acids. insulin and leptin
lipid-derivatives
synthesized from fatty acids. can diffuse across plasma membrane easily. local hormones, sending signals over a short distances, main class is steroid
steroid
lipid derivatives. bind to receptors in cytoplasm or nucleus, activate specific genes, transcription and translation levels of these genes increase, protein/enzyme level increase=response
thyroid hormone
lipid derivatives. complex modify transcription levels(nucleus) and increase ATP production(mitochondria)
central controller?
hypothalamus area of the brain regulates the endocrine system. Regulates the pituitary gland(produces&releases several hormones, also has anterior&posterior lobes)
pituitary gland-posterior lobe
(neurohypophysis) consists of neuroglia and axon from the the hypothalamus. hypothalamus synthesizes the hormones and migrate along axons into posterior to get released.
pituitary gland-anterior lobe
(adenohypophysis) filled with glandular tissue. secretes hormones that impact secretion of other endocrine glands.
anterior lobe 2 types of regulatory hormones that control this lobe
Releasing hormone(RH): stimulate the synthesis and secretion of hormone
Inhibiting hormone(IH):prevents the synthesis and secretion of hormones
6 hormones released by anterior pituitary
1)thyroid stimulating hormone(TSH)
2)Adrenocorticotropic hormone(ACTH)
3) follicle stimulating hormone(FSH)
4)Luteinizing Hormone (LH)
5)Prolactin
6)Growth hormone
Thyroid stimulating hormone(TSH)
controls secretion of thyroid hormone(thyroxine) from gland. increase in thyroid hormone->inhibit TSH release(negative feedback)
decrease in thyroid hormone->hypothalamus sends signal
Adrenocorticotropic hormone (ACTH)
controls secretion of glucorticoids(cortisol and androgen) hormones from the adrenal cortex. role in how body responds to stress
Follicle stimulating hormone (FSH)
stimulates follicle/sperm development
luteinizing hormone (LH)
promotes ovulation. released via gonadotropin-releasing hormone(GnRH). inhibited via negative feedback loop, reducing GnRH
Prolactin (PRL)
targets mammary glands&stimulate milk production. released with prolactin releasing hormone(PRH) from hypothalamus, inhibited via negative feedback by PRL on PRH.
growth hormone (GH)
stimulates cell growth and replication. GH levels are regulated by a balance of GH releasing hormone
Posterior lobe hormones?
Oxytocin and antidiuretic hormone (ADH)
Oxytocin
posterior lobe hormone:induce smooth muscle contractions of the uterus during childbirth, stimulate milk release, affect social behaviors(“cuddle hormone”)
antidiuretic hormone(ADH)
posterior lobe hormone: maintain blood pressure, blood volume and tissue water content by controlling the kidney and constricts blood vessels
thyroid gland
endocrine gland that produces certain hormones involved in metabolic rate, growth,&development&heat production in most cells
thyroid follicle cells produce
thyroxine(T4 90%)
triiodothyronine (T3 10%)
play a role in metabolism, temp
-increase in ATP production
-increase in glucose catabolism
-increase in NKA
-increase in heat production
Thyroxine(thyroid)
controls metabolic rate in digestion, heart muscle, brain development, bone maintenance
calcitonin
released by the parafollicular cells help regulate blood Ca2+ levels.
increase in blood Ca2+ levels trigger release of calcitonin, lead to inhibition of bone resorption by osteoclasts and stimulation of Ca2+ excretion by kidney
parathyroid gland
regulates when blood Ca2+ is too low, releases parathyroid hormone(PIH)
are 4 small glands located on posterior surface of thyroid gland
adrenal gland
small triangular shaped glands on top of each kidney. produce hormones to help regulate metabolism, immune system, and blood pressure.
adrenal gland hormones?
Aldosterone, cortisol, androgen&estrogen, epinephrine&norepinephrine
Aldosterone?
-adrenal gland hormone
-help control the balance of water&Na+ by affecting the kidney, salivary&sweat glands
-low Na+ level or high K+ renin stimulates aldosterone release which increase water reabsorption by kidneys
-high blood pressure, hatriuretic peptide hormones released from heart inhibits aldosterone release
Cortisol
-adrenal gland
-stress hormone released in fight ot flight response
-stimulates gluconeogenesis causing increase in blood glucose levels
androgen&estrogen
-adrenal gland
-sex hormone stimulated by ACTH
-necessary for sexual development&for regulation of the menstrual cycle
Epinephrine&norepinephrine
-adrenal gland
-adrenaline&noradrenaline
-a neurotransmitter fight or flight hormone stimulated by sympathetic NS
-
pancreas
has exocrine glands but also endocrine glands, produces hormones: glucagon, insulin,&more
pineal gland
produces melatonin, in response to darkness
Increase in blood glucose?
insulin releases via parasympathetic stimulation, activates glucose catabolism, excess glucose is stored as glycogen in skeletal muscle&liver or converted to fat, blood glucose drops, negative feedback inhibits further release
decrease in blood glucose?
liver&skeletal muscle converts glycogen to glucose, stimulates conversion of fatty acid&amino acid to glucose, blood glucose level increase, glucagon levels fall back via negative feedback
Gonads:Testes
cells produce androgens&testosterone.FSH&LH trigger testosterone release from gonads, negative feedback inhibits androgen release from gonads
gonads:ovaries
synthesize estrogen. FSH&LH trigger estrogen release, especially estradiol, inhibited via negative feedback on FSH
3 hormones released by kidneys?
1)Calcitriol
2)Erythropoietin(EPO)
3)Renin
Erythropoietin(kidney hormone)
stimulates red blood cell production in response to hypoxia at kidneys
Calcitriol(kidney Hormone)
increase Ca2+ & PO3 2+ absorption by the digestive tract in response to PTH stimulation
Renin(kidney hormone)
stimulates aldosterone &ADH in response to reduced renal bllod pressure restoring it
heart hormones
cardiac muscle cells release atrial or ventricular natriuretic peptide(ANP&BNP)
Adipose tissue
-produce leptin which regulates energy homeostasis & metabolism.
-increase in glucose & lipid levels in adipose cells release leptin
-leptin targets hypothalamus, suppressing appetite
