Endocrine System Flashcards
Introduce the endocrine system
This system consists of glands which are widely separated with no physical connection to one another.
Controlled by the Hypothalamus, the pituitary gland is the master control gland.
surrounded by networks of capillaries and no ducts, hormones are secreted directly into the blood stream.
What are the 2 parts of the pituitary
Anterior and Posterior
Anterior made of glandular tissue
Posterior made of nervous tissue from the brain
How are the antiror and Posterior lobes of the pituitary gland different
Antirior secretes hormones while the posterior stores hormones
what hormones do the anterior pituitary and hypothalamus store
Hypothalamus releases the ‘releasing hormone’ to those stimulated in the pituitary
Growth Hormone
Thyroid Stimulating Hormone (Thyroid gland T4+T3)
Pro-lac-tin hormone (Breast tissue development)
Gona-do-tropic Hormone (Testies and Ovaries)
What hormones do the posterior gland secrete
Anti-diurectic (ADH) To preserve water loss
oxy-to-cin To contract walls of uterus and breast milk
Function of the Pineal Gland
Plays function of secreting melanin for the sleep wake cycle.
Plays function in Cardiac Rhythm and development of sex organs in puberty
What is T3 and T4
These are atoms of iodine
Thyroid gland takes up iodine from the blood called iodine trapping.
thyroxin= T4
tri-iodo-thyroxin= T3
Explain the effects of an under active and over active thyroid
When the thyroid gland releases too much T’s into the blood: Anxiety, high metabolism, Hair loss, dihorea
When thyrroid gland releases too little T’s into the blood: Depression, bradychardia, weight gain, constipation.
what do the parathyroid glands do
Secrete PTH which regulated calcium levels
This hormone secretes osteclasts which eliminates bone destroying cells.
Where are the parathyroid glands
embeded onto the the posterior surface of each thyroid gland
what are the 2 sections of the adrenal gland
Adrenal medulla and Adrenal Cortex
What is the function of the adrenal medulla
Part of the sympathetic nervous system Secretes adrenaline (80%) and Noradrenaline (20%)
what is the function of the adrenal cortex
secretes steroid hormones from cholesterol Gluco-corticoids mineral-corticoids gonadocortisoids - sex hormones 'gluco, mineral and gonado'
what hormones are secreted by the pancreas
insuline- reduces
glucagon- increases
Somatostatin- inhibits the secretion of these hormones
what are male sex hormones called
androgen’s
What is positive feedback
Amplify changes and move the body away from its equilibrium ie.child birth
stretch–nerve impluse–release of oxytocin- smoother muscle
what is a negative feedback loop
More common than positive feedback loops.
A reaction to the body that causes a decrease in function in relation to a stimulous.
eg. High blood pressure—ADH—absorbed water in kidneys—pressure lowered
Sympathetic nervous system
secretes adrenaline to speed up bodily functions
para- sympathetic nervous system
slows down
What is a hormone cascade
One hormone controls the secretion of another
Draw a diagram of the hormone cascade the HPA axis
STRESS- ACTION POTENTIAL releases NEURONS in the HYPOTHALMUS- CRH hormone- PITUITARY release ACTH- ADRENAL CORTEX releases clucogon and ADRENALINE- Fight/ Flight
What is the job of the hypothalmus
hub of where the nervous system and endocrine system meet to control homeostasis
what type of cells are insuline and glaucogon
insuline is beta
Glaucogon is Alpha
How does insuline work
Increases the rate at which the cells absorb glucose to lower blood sugar
How does Glaucogon work
Slows down the rate at which cells absorb glucose to increase circulating blood sugar
