RAAS And Pineal Gland Flashcards
PINEAL GLAND
- aka _____
- is in the __cephalic area of brain (above or below?) the hypothalamus
- its a small ____ shaped structure with a length of about _____
-has 2 types of cells:large epithelial cells called _____ cells, and _____ cells
epiphysis
dien
Above
cone ; 10mm
parenchyma
neuroglial
in adults the pineal gland is _____ but the _____ cells exists and secrete the hormonal substance
calcified
epithelial
FUNCTIONS OF THE PINEAL GLAND
- controls sexual activity in animals by regulating the ______
- secretes the hormonal substance called _____
seasonal fertility
melatonin
Pineal gland plays a major role In regulating the sexual functions in humans
T/F
F
Just a little
MELATONIN
- secreted by the _____ cells of pineal gland
- melatonin is an indole (________)
parenchymal
N-acetyl-5-methoxytryptamine
ACTIONS OF MELATONIN
-it acts mainly on gonads
T/F
T
Melatonin’s actions differ from species to species
T/F
T
in some animals melatonin stimulates gonads,while in other animals it inhibits gonads
T/F
T
in humans, melatonin _____ the onset of puberty by ____ing the ____
inhibits
inhibit
gonads
Diurnal variation in melatonin secretion
-melatonin secretion is (less or more?) in darkness than in daylight
more
in animals , the secretion of melatonin varies according to activities in different periods of the day
T/F
T
______ is responsible for the circadian flunctuations of melatonin secretion
hypothalamus
RENIN ANGIOTENSIN ALDOSTERONE SYSTEM
RENIN
- _______ produces and secretes certain enzyme which include renin
- renin is produced by the _________
- is a peptide with ____ amino acids
kidney
juxtaglomerulus apparatus
340
along with Angiotensins, renin forms the ______ system , which is a hormone system that plays an important role in the maintenance of _____
renin-angiotensin
blood pressure
Stimulants for renin secretion
Secretion of renin is stimulated by four factors
- (rise or fall?) in arterial blood pressure
-(increase or reduction?) in ECF volume
-(increased or decreased ?) sympathetic activity
-(increased or decreased?) load of sodium and chloride in ______
fall
reduction
increased
decreased
macula densa
Renin - angiotensin system
-when renin is released into the blood , it acts on a specific plasma protein called _______ or renin substrate
angiotensinogen
RAAS
By the activity of renin , the angiotensinogen is converted into a ____peptide called _____
deca
angiotensin 1
RAAS
angiotensin 1 is converted tO ______ which is an ___peptide by the activity of _____ secreted from the ____
angiotensin 2
octa
ACE
lungs
RAAS
Angiotensin 2 has a (short or long ?) half life of about ______ then it’s rapidly degraded into a ___peptide called _____ by _______ which are present in ____ cells and vascular beds in many tissues
Short
1-2 minutes
hepta
angiotensin 3
angiotensinases
RBCs
ACTIONS OF ANGIOTENSINS
-AG1 is physiologically (active or inactive?) and serves as the precursor of ____ which is the most (active or inactive ?) form of the Angiotensins
inactive
AG2
active
Angiotensin actions are :
On blood vessels
- AG2 _____ arterial blood pressure by directly acting on the blood vessels and causing vasoconstriction.
- it ______ blood pressure (directly or direindirectly by increasing the release of noradrenaline from postganglionic sympathetic fibers.
increases
increases
AG2 is a potent constrictor of the arterioles
T/F
T
NE is a general vasoconstrictor
T:F
T
Angiotensin actions are:
On Adrenal cortex:
-stimulates zona _____ of adrenal cortex to release _____
glomerulosa
aldosterone
