bio Test 2 Endocrine system Flashcards
(36 cards)
Endocrine vs Exocrine glands
Endo: Secrete hormone directly in suroundings
Exo: Secretion delivered to body cavity/outside body (sweat)
secretion = pas Hormone
similarity to nervous system
both are communication system
2 differences from nervous system
- Produces respond that take longer time to be seen
- produces respond that are less specific
2 chemical classes:
Derived from amino acids
derieved from Cholesterol
2 chemical classes:
1. derieved from amino acids
- Extracellular receptor (on cell membrane)
- Circulate freely in blood
- Hydrophilic
- CANNOT go across cell membrane freely
2 chemical classes:
2. Derieved from cholesterol
- Intracellular (in cell)
- Circulate in blood with help of transport protein
- Hydrophobic
- Can go across cell membrane freely
What is an Extracellular receptor
hormone (amine, peptide, protein) bind to a protein receptor on the cell’s surface
signal sent inside cell causing chain reactions
protein receives a phosphate group + gets activated
What is an Intracellular receptor
homone (steroid, thyroid) and receptor enters nucleus + attach to DNA
gene activated + protein produced
What is downregulation
Target cells DECREASE # of receptors due to HIGH hormone concentration
What is upregulation
Target cells INCREASE # of receptors due to LOW hormone concentration
Goal of regulation loops
maintain body conditions within acceptable range by setting up dif. mechanisms when deviations happen
3 components of a loop
Sensor: receptor monitors the conditions
Control center: Compares signals from sensors to norms+ activates effector if needed
Effector: gland/organ that work bring conditions back in normal range
What is a positive loop
Release of hormone + its increasing concentration lead to more productions of the hormone (ex: oxytocin, birth)
What is a negative loop
Release of hormone + increasing concentration to PREVENT more production of the hormone
3 Endocrine glands stimuli:
Non-hormone chemicals
hormones
electrical signals
- Non-hormone chemicals: receptors on gland sense environment + trigger hormone secretion = respond
- Hormone: Many homones produced by hypo + pituitary regulate prod. hormone by other gland
- Electrical signals: parasympatic/sympatic divisions of PNS, activate release hormones
Hypothalamus-Pituitary complex:
what does it do (3)
1.command center of endocrine sys
2.produce hormone
3.Physically linked by infundibulum
Hypothalamus-Pituitary complex:
Anterior pituitary(4)
-produces hormones (controlle by hypo hormones)
-hypo hormones circulate inside blood vessel down to pituitary gland
-hypo release hormone = increase secretion of pituitary hormones
-hypo inhibiting hormones = decrease of pituitary hormones
Hypothalamus-Pituitary complex:
Posterior pituitary
-Ectention of hypo (share neurons)
-store hormone produced by hypo
Thyroid gland:
where is it and what does it contains
- located neck region, wrappend around trachea, 2lobes in which parathyroid glands embedded
-contains Follicules cells filled with Colloid
-TH produce by Colloid
Parathyroid gland:
where and what does it do
- Back of thyroid gland
participate in regulations of bolld, calcium level with PTH
Parathyroid gland:
2 Disorders
1. hyperparathyroidism
2. Hypoparatyroidism
- PTH overproduction excessive calcium remover from bones, weak bones, fractures
2.PTH deficiency, very low concentration of calcium in blood, muscle twitching, cramping, spasms
Adrenal glands:
what it is and where
Masses of cells sitting on top of each kidney
Adrenal glands:
2 layers
Cortex: outer layer, releases steroid +regulated by anterior pituitary hormone -ACTH
Medulla: inner layer, release amine, controlled by nerve impulses
Pancreas
where and part that releases hormones
Behind stomach
Islet:
Apha-produce glucagon
Beta-produce Insulin
