Excretion, Co-ordination adn responses Flashcards
Where is water reabsorbed in the nephron
Loop of henle and collecting duct
Where are salts reabsorbed in the nephron
Loop of Henle
Where is glucose reabsorbed in the nephron
Proximal convoluted tubule
Function of the cornea
Transparent lens that refracts light as it enters the eye
Function of the iris
Controls how much light enters the pupil
function of lens
Transparent disc that can change shape to focus light onto the retina
function of the retina
Contains light receptor cells - Rods (detect light intensity) and cones (detects colour)
Function of the optic nerve
Sensory neuron that carries impulses between the eye and the brain
Function of the pupil
Hole that allows light to enter the eye
What happens to the eye when the person entered a dark room
- Radial muscles of iris contracted
- Circular muscles of iris relaxed
- Dilated pupil (more light enters eye)
Eye change when looking at a near object
-Ciliary muscles contract
-Suspensory ligaments loosen
- Lens shape will be thicker
- Light is refracted strongly
Eye change when looking at a distant object
- Ciliary muscles relax
- Suspensory ligaments tighten
- lens shape become thinner
- Light is only refracted slightly
What is vasoconstriction and when does it happen
It happens when the person is cold. The arterioles will shrink, therefore it will be further away from the skin. Less heat will be lost and blood flow in skin capillaries will decrease
What is vasodilation and when does it happen
It happens when the person is too hot. The arterioles will get wider so more heat will be lost as it is closer to the skin. The blood flow in skin capillaries will increase.
where is insulin produced and what is it used for
- Produced in the pancreas
- Controls blood sugar level.
where is testosterone produced and what is it used for
- Produced in the male testes
- responsible for the development of secondary sexual characteristics in males
What does progesterone do and where is it produced
-Produced in the female ovaries
- Used for maintaining the uterus lining during pregnancy
- It stops the release of FSH andLH which releases the eggs.
What does Oestrogen do and where is it produced
-produced by the female ovaries
- Used for the development of secondary sexual characteristics in females and regulating the menstrual cycle
- It causes growth and repair of the lining of the uterus wall
How is the ADH used in osmoregulation
Water content of the blood falls below a certain if dehydrated.
More ADH released
collecting ducts more permeable for water to be reabsorbed
Less urine and more concentrated
Where is LH and FSH produced and what do they do
They are both released in the pituitary gland
LH: Stimulates the ovary to produce progesterone
FSH: Causes egg to start maturing in the ovary. It also stimulates the ovaries to start releasing oestrogen.
