Intro Y11 - Excretory And Endocrine System Flashcards
Excretion
The process of eliminating or expelling waste matter
Organs of excretory system
x2 kidneys
Ureter
Bladder
Urethra
Kidney
Filters waste from the blood and regulates water balance
Blood enters through the renal artery which then branches into smaller blood vessels
Nephron
Microscopic structural and functional unit of the kidney
Components of a nephron
Bowman’s capsule
Proximal convoluted tuble
Loop of Henley
Distal convoluted tuble
Bowman’s capsule
To filter the blood
Proximal convoluted tuble
Reabsorption of glucose, ions and amino acids
Loop of henle
Reabsorption of water
The ascending limb pumps ions out of the tuble into the surrounding tissue this makes the tissue around the descending limb highly concentrated, so water exits
Distal convoluted tubule
Selective Reabsorption of water
Ureter
A duct that carries urine from the kidney to the bladder
Bladder
A storage organ for urine
Urethra
Carries urine out of the body
Small volume and dark coloured urine indicates
High concentrated urine and water has been retained by the body due to dehydration
Dehydrated
Body needs to retain water > more water reabsorbed by distal convoluted tubule > smaller volume of urine and more concentrated
Vice versa
Endocrine system
A network of glands in animals that secrete hormones into the blood to travel nearby/ distant target cells
Gland
A group of cells which secrete the hormones into
Hormone
A chemical signalling molecule secreted directly into the bloodstream by a gland which travels to a target cell
Receptors
Target cells which have a specific and complimentary receptors for the hormone
This is why certain cells respond to certain hormones
Hypothalamus (gland)
An a=organ of the endocrine system which regulates hormones, coordinates activity of the pituitary and regulates processes to maintain homeostasis
Antidiuretic hormone (ADH)
Made in hypothalamus and stored in pituitary gland
Causes kidneys to release less water > decreases amount of urine produced
Acts on distal convoluted tubule causing Reabsorption of water into the bloodstream
Pancreas (gland)
An organ of the endocrine system that releases hormones that regulate blood glucose levels
Glucose regulation
Regulated by negative feedback loop
Controlled by x2 hormones: insulin and glucagon
Glucose. >insulin > glycogen
Glycogen > glycogen > glucose
Insulin
Released by beta cells in the pancreas in response to high blood glucose levels
Increases the uptake of glucose into body cells
Stimulates the conversion of glucose into glycogen
Lowers blood glucose levels
Glucagon
Released by alpha cells in the pancreas in response to high blood glucose levels Increases
Stimulates the conversion of glycogen into glucose
Increases blood glucose levels
