chapter 19 part 1 Flashcards
endocrine system
-long term general responses
-releases hormones (leave glands)
endocrine tissues
heart, kidney, adipose cells, digestive tract
4 groups of excitatory hormones
-amino acid derivatives
-peptide hormones
-steroids
-eicosanoids
amino acid derivative
-structure is similar to amino acids
-ex: thyroid hormones and adrenal medulla are derivatives of tyrosine
-also melatonin
peptide hormones
chains of amino acids
-all hormones from the pituitary gland
steroids
derivatives of cholesterol
-reproductive hormones
eicosanoids
derived of arachidonic acid (twenty carbon)
-fatty acid of cell membrane
-thromboxane, prostaglandin and leukotriens
3 mechanisms of hypothalamus
-secrete regulatory hormones
-act as endocrine organ
-contain autonomic nervous system centers
secreting regulatory hormones
secretes releasing and inhibiting hormones
acting as an endocrine gland ON TEST
release antidiuretic hormone and oxytocin to the potuitary gland
autonomic nervous system center
control over the adrenal medulla through the sympathetic nervous system
pituitary gland
-the hypophysis
-attached to hypothalamus through the infundibulum
-in the hypophyseal fossa of sella turcica
-has 2 lobes (the adenophypophysis and neurohypophysis)
adenohypophysis
anterioir lobe of pituitary that releases nine peptide hormones
-releases neurepinephrine and epinephrine
-three regions (pars distalis, intermedia and tuberalis)
neurohypophysis
posterior lobe of pituitary that releases two peptide hormones
-releases anti diuretic and oxytocin
-target nephrons to retain water and prevent dehydration (antidiuretic)
-elevated blood pressure by constricting preipheral b.v. (anti diuretic)
antidiuretic
-targets nephrons and b.v.
-also called vasopresun
-ADH
oxytocin
-targets smooth muscle
-OT
-targets cells of mammary glands
-release milk
-also contractions during birth
-in males the smooth muscles contraction is in the prostate gland
pars distalis
secretes the majority fo hormones
pars intermedia
secrete melanocyte-stimulating hormone
pars tuberalis
wrap around a portion of the infundibulum
cell types of adenophyophysis
-thyrotropes
-corticotropes
-gonadotropes
-lactotropes
-somatotropes
thryotropes
release thyroid stimulating homrone
corticotropes
release adrenocroticotropic hormone (ACTH) and melanocyte stimulating hormone (MSH)
gonadotropes
release follicle stimulating hormone (FSH) and luteinizing hormone (LH)
lactotropes
release prolactin (PRL)
somatotropes
release growth hormones (GH) and somatotropin
hypophyseal portal system
-in the infundiculum
-is a plexus of capillaries
-capillaries are fenestrates (have pores)
-regulating hormones leave hypothalamus and pass through blood vessels to the anterior pituitary (adenophypophysis)
thyroid stimulating hormone
-targets thyroid gland
-causes thyroid to release hormones (calcintonin, thyroxine, and triiodothryonine)
-these hormones all have iodide
adrenocorticotropic hormone
-target adrenal cortex
-adrenal cortex releases glucocorticoids (steroids)
FSH
-target female ovaries
-release estrogen
-cause egg matureation (oocyte)
-seminiferous tubules in men
-cause sperm production
LH
-target ovaries
-release progesterone
-release of egg from ovary
-target interstitial cell in testes
-release testosterone (androgens)
-release estrogen
prolactin
-milk
GH
-somatotopin
-target skeletal muscle
-cause protein synthesis causing growth
-target liver cells
-releases somatomedin (stimulate protein synthesis in muscles and cartilage)
thyroid gland
-supplied by the superior thyroid artery (from the external carotid)
-supplied by the interior thyroid artery (from the thyrocervical trunk)
-made of 2 lobes (separated by isthmus)
-has follicles
-ONLY gland to store hormones products
thyroid follicles
-lines w simple cuboidal cells and t thyrocytes *follicular cells
follicular cells
-secrete thyroglobulin
-transport iodine into the follicle
-combining iodine and thyroglobulin forms thyroid hormones
