Endocrine Flashcards
What do the nervous system and the endocrine system have in common
Animals need to respond to external
changes and control conditions inside
their bodies in order to maintain
homeostasis. Two body systems are
used to achieve this.
Define Homoeostasis
how the body maintains a
relatively stable internal state despite
changes inside and around it. This constant
internal environment is maintained through
the efforts of the nervous system and the
endocrine system.
Name the 7 endocrine glands
1- Hypothalamus
2- pituitary gland
3- Thyroid gland
4- Adrenal
5- islets of Langerhans
6- testis
7- Ovary
what is the location and Hormone of the hypothalamus
L- small region of
the brain located at the base of the
brain, just above the pituitary gland
H- Secretes Anti~diuretic hormone
ADH
Oxytocin
What is the role of Oxytocin and ADH
ADH- It enlarges the pores of the
collecting ducts of the nephron, so
more water can be reabsorbed
from the filtrate back into the
blood.
Oxytocin- stimulates contractions of the uterine muscles which causes labor
simulates milk flow
What is the location and hormone secreted by the pituitary gland
L- underneath the hypothalamus behind the bridge of the nose
H- TSH, FSH, LH, prolactin,
growth hormone and
oxytocin
What are the roles of TSH, FSH, LH, prolactin,
growth hormone and
oxytocin
TSH- Stimulates the thyroid to
secrete the hormone
thyroxin
FSH- Stimulates the formation of follicles in ovary and sperm in testis
GH- Stimulates growth of the body
LH- Brings about ovulation, oestrogen production and corpus luteum development and stimulates cells of Leydig to produce testosterone
Prolactin- Stimulates the mammary glands into secreting milk
Oxytocin- Stimulates contractions of the uterine muscles which causes labor
Location and hormone of the thyroid gland
L- Butterfly shaped gland that lies around the front of the trachea
H- thyroxin
Role of thyroxin
Regulates metabolic rate
Location and hormone of Adrenal gland
L- on top of each kidney
H- Adrenalin, Aldosterone
Function of Adrenalin and Aldosterone
Adrenalin- prepares body for crisis by increasing: heart rate, breathing, glucose levels in blood and tone of skeletal muscles
Aldosterone- promotes the reabsorption of sodium ions and water
Location of Islets of Langerhans and hormones
L- in pancreas
H- insulin and glucagon
Function of insulin and glucagon
I- Decreases blood sugar levels
G- increases blood sugar levels
Location and Hormone of testis
L- oval shaped organ located in the scrotum just behind the penis
H- testosterone
Role of Testosterone
Stimulates male sex organs and stimulates secondary sexual characterics in men
Location and Hormone of Ovaries
L- located on either side of the uterus in the lower abdomen
H- Oestrogen and Progesterone
Role of Oestrogen and Progesterone’s
O- stimulates female sex organs and stimulates secondary sexual characteristics
P- Ensures endometrium doesn’t disintegrate during pregnancy and prepares uterus to receive fertilized ovum
What is the principle of the negative feedback system
Any deviation from the normal state is rectified by causing a change to occur in the opposite direction so that the deviation is cancelled
What is the general formula for the negative feedback when hormones rise above normal state
rise above normal- receptor detects change- control Centre processes information- reaction from gland- back to normal level
What is the general formula for the negative feedback system when it is lower than normal
drop below normal- receptor detects change- control Centre processes information- reaction from gland- back to normal state
What is the negative feedback system for a rise in thyroxin in blood
Rise above normal- pituitary gland detects rise in thyroxin levels- pituitray gland stops secreting TSH- thyroid gland stops secreting thyroxin- normal state
Negative feedback for a rise in glucose levels
level rises above normal- pancreas detects rise in glucose level- B cells of islets of Langerhans in pancreas secrete hormone insulin- insulin converts excess glucose to glycogen insulin promotes the entry of glucose into body cells- blood glucose levels drop
When glucose drops below normal
glucose levels drops below normal- Pancreas detect drop in glucose level- alpa cells of islets of langerhans in pancreas secrete the hormone glucagon- Glucagon converts stored glycogen to glucose- glucose levels rise
when is insulin normally screted?
after a meal, after carbs have been ingested
how would insulin boost levels of glygogen in blood
insulin causes the muscle cells to absorb glucose from blood, and convert it to glycogen for storage. This reduces the level of glucose in the blood
