Chapter 7: Endocrine And Exocrine Flashcards
1
Q
Agonist vs antagonist
A
- Agonist: any molecule that binds to the receptor and elicits the response
- Antagonist: any molecule that binds to the receptor and prevents the response
2
Q
Chemical signalling mechanisms
A
- Autocrine: signals itself
- Paracrine: signals nearby
- Endocrine: signals far and travels via blood
3
Q
Types of hormones: peptides
A
- Anterior pituitary: FSH, LG, ACTH, TSH, Prolactin, endophins, GH
- Posterior pituitary: ADH, Oxytocin
- Parathyroid hormone: PTH
- Thyroid: calcitonin
- Stomach: gastrin, ghrelin, leptin
- Small intestine: CCK
- Pancreas: glucagon, insulin, somatostatin
- Liver: angiotensinogen
- Kidney: renin
- Heart: ANP
4
Q
Types of hormones: steroids
A
- Derived from cholesterol (3 cyclohexane and 1 cyclopentane)
- Formation begins in cytosol and is carried via albumin
- Important steroid hormones
3a. Glucocorticoids and mineralcorticoids of adrenal cortex: cortisol and aldosterone
3b. Gonadal hormones: estrogen, progesterone and testosterone
5
Q
Types of hormones: amino hormones
A
- Tyrosine derived
1a. Stored in thyroid follicles and slowly released: T3 and T4
1b. Catecholamines: dopamine, epinephrine and norepinephrine - Tryptophan derived
2a. Serotonin and melatonin - Histidine derived
3a. Histamine: from mast cells and basophils
6
Q
Types of hormones: amino hormones
A
- Tyrosine derived
1a. Stored in thyroid follicles and slowly released: T3 and T4
1b. Catecholamines: dopamine, epinephrine and norepinephrine - Tryptophan derived
2a. Serotonin and melatonin - Histidine derived
3a. Histamine: from mast cells and basophils
7
Q
Ligand gated ion channel receptors
A
- Ion channel that when bound by hormone opens or closes
8
Q
Intracellular receptors
A
- In cytosol or nucleus and associated with steroid or thyroid hormones
9
Q
GPCR
A
- Integral protein whose TM region spans the membrane 7 times
- When inactive, its alpha subunit is bound to GDP
10
Q
Enzyme linked receptor
A
- TM protein that is either an enzyme itself or is attached directly to an enzyme inside the cell
11
Q
Second messenger systems
A
- CAMP: GPCR activated adenylyl cyclase which converts ATP to cAMP which activates protein kinase A or PKA
- Phospholipid breakdown: phospholipase C (PLC) cleaves PIP2 to DAG and IP3 which binds to Ca2+ and opens it on ER…DAG and Ca2+ then activate PKC
- Calcium and calmodulin: Ca2+ may activate calmodulin which phosphoylates more enzymes
12
Q
Endocrine glands: hypothalamus
A
- Master gland
- Regulates anterior pituitary by releasing tropic hormones and inhibiting hormones into hypophyseal portal system
2a. Tropic hormones are hormones that cause release of other hormones
13
Q
Endocrine glands: anterior pituitary
A
- Only releases peptide hormones
1a. FSH
1b. LH
1c. ACTH: stimulates adrenal cortex to release glucocorticoids (Stress hormones) via GPCR that uses cAMP to activate protein kinase
1d. TSH: stimulates thyroid to release T3 and T4
1e. Prolactin: promotes lactation
1f. Endorphins: natural pain killer
1g. GH: targets all cells of the body for growth
14
Q
Endocrine glands: Posterior pituitary
A
- Oxytocin: increases uterine contraction and causes milk ejection
- ADH/vasopressin: reduces and concentrates urine which increases blood pressure
15
Q
Endocrine glands: Adrenal cortex
A
- Mineralocorticoids: aldosterone
1a. Increases Na+/Cl- reabsorption and K+/H+ secretion which increases blood pressure & blood volume - Glucocorticoids: cortisol