chapter 9 endocrine system Flashcards
hormones can only affect target cells and organs that have what?
receptors for that specific hormone
what happens if a cell or organ does not have receptors for a hormone it comes into contact with?
nothing happens the cell or gland does not respond
what chemical classifications are there for hormones?
1) amino acid based
2) steroids
3) prostaglandins
amino acid based hormones include:
1) proteins
2) peptides
3) amines
what are steroids made of?
cholesterol
what are prostaglandins made of?
highly active lipids that act as local hormones
how is hormone secretion regulated?
a self adjusting mechanism called a feedback loop
what are the two types of feedback loops?
1) negative feedback loop
2) positive feedback loop
which feedback loop is less common in the human body?
positive feedback loop
positive feedback loop:
*stimulus does not produce an opposite effect like a negative feedback loop does
*the stimulus accelerates the process
what feedback loop has a counteractive effect?
negative feedback loop
1) a person eats food and glucose levels in the blood rise.
2) insulin is released, bringing glucose levels back down.
3) homeostasis is accomplished
what type of feedback loop is this?
negative feedback loop
what is the interface between the nervous system and the endocrine system?
the hypothalamus
what is the hypothalamus aka and why?
the master gland (control center)
because it controls and oversees most endocrine function
the hypothalamus controls most endocrine activity in what 3 ways?
1) controls the release of regulatory hormones from anterior pituitary gland.
2) posterior pituitary gland secretes oxytocin(OT) and antidiuretic hormone (ADH)
3) controls stimulation and secretion activities of the adrenal medulla
what is the pituitary gland aka?
hypophysis
where is the pituitary gland housed?
inferior to the hypothalamus within the sella turcica of the sphenoid bone
what connects the pituitary gland to the hypothalamus?
a thin stalk called the infundibulum
what is the pituitary gland divided into?
anterior and posterior lobes
what is the anterior pituitary gland aka?
adenohypophysis
what type of tissue is the anterior pituitary gland made of?
epithelial tissue derived from the roof of mouth during developement
how do regulating hormones get from the hypothalamus to the anterior pituitary?
they travel through a blood vessel network called the hypothalamohypophyseal portal system
what are the seven major hormones secreted from the anterior pituitary?
1) thyroid stimulating hormone (TSH)
2) prolactin (PRL)
3) adrenocorticotropin hormone (ACTH)
4) growth hormone (GH)
5) follicle stimulating hormone (FSH)
6) lutenizing hormone (LH)
7) melanocyte stimulating hormone (MSH)
what is growth hormone aka?
somatotropin
what is the posterior pituitary derived from?
embryonic diencephalon
what is the neural connection between the hypothalamus and the posterior pituitary?
hypothalamohypophyseal tract
what 2 hormones are released by the posterior pituitary?
1) vasopressin (anti-diuretic hormone)
2) oxytocin
what are adrenal glands aka?
suprarenal glands
what parts are the adrenal glands divided into?
1) capsule
2) outter cortex
3) inner medulla
what is the adrenal outter cortex controlled by?
adrenocorticotropin
what is the adrenal medulla controlled by?
nerves of the autonomic nervous system
where is the adrenal capsule located?
around the outside of the outter cortex
where is the pancreas located?
between duodenum and spleen, posterior to the stomach
is the pancreas endocrine or exocrine?
both
what are pancreatic acini?
pancreatic cells that produce digestive enzymes to secrete into the small intestine
what % of pancreatic cells do pancreatic acini make up?
98-99%
what are pancreatic islets?
endocrine cells that closely regulate levels of glucose in the blood
what % of cells in the pancreas do pancreatic islets make up?
1-2%
what are the different types of pancreatic islets and what does each one secrete?
1) alpha cells - glucagon
2) beta cells - insulin
3) delta cells - somatostatin
4) F cells - pancreatic polypeptide
type 1 diabetes =
insulin dependant (autoimmune, destroys beta cells)
type 2 diabetes =
insulin resistant.
cells dont respond to insulin.
overproduction wears out beta cells
what is the largest gland that is devoted to the endocrine system?
thyroid gland
where is the thyroid gland located?
inferior to the cricoid cartilage
what do follicular cells in the thyroid produce?
what does production require?
thyroid hormones (T3 and T4)
iodine is required
C-cells in the thyroid are aka?
parafollicular cells
what do C-cells in the thyroid produce?
calcitonin
what is a goiter?
what is the most common cause?
abnormal enlargement of the thyroid gland most commonly caused by an iodine deficiency
