Flashcards in Excretion Deck (22)
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1
Excretion
The removal of metabolic waste from the body
2
Homeostasis
The maintenance of a constant internal environment in an organism
3
Ectotherms
Gain or lose heat from or to their external environment
Eg. Frogs, snakes , fish
4
Endotherms
Generate their own heat from metabolic reactions.
Eg . Humans , dogs
5
Role of excretory system in homeostasis
-regulating body temp
-controls osmosis
-controls concentration of body fluids
- removes waste products of body
6
Organs of excretion
Lungs - water + CO2
Skin - water + salts
Kidneys - water, salts , urea
7
Urinary system
2 kidneys , 2 ureters, the bladder and the urethra
8
Functions of the kidney
- excretion
- osmoregulation
- pH control
9
Filtration in kidney
Incoming blood is filtered in the outer cortex
10
Reabsorption in kidney
Useful materials are then taken back into the blood in the cortex and medulla
11
Secretion in kidney
Substances are secretes from blood into the cortex
12
Nephrons
Carry out functions of kidneys.
Located in cortex and medulla of the kidney
13
Where does filtration take place?
Glomerulus
14
Ultra-filtration
Filtration in the Bowman Capsule as there is high pressure
15
Epidermis
Outer layer of skin
16
Melanin
Specialised cells created in malphigian layer. Protects skin against UV radiation
17
Malphigian layer
Pigments skin, hair and colour of eyes
18
Dermis
Inner layer of skin , contains strong protein called collagen
19
Subcutaneous layer
Contains fat in adipose tissues
20
Functions of the skin
Protection
Vitamin production - D
Food store - fat
Sense organ
Excretion - sweat
Temperature regulation
21
ADH
Anti diuretic hormone.
Volume of urine produced is controlled by this hormone
22
