Response Flashcards
What does a coordinated response require?
A stimulus
A receptor
An effector
The reflex sequence
1 stimulus - the sense organ detects it 2 receptor 3 coordinator - brain or spinal cord 4 effector 5 response
The central nervous system consists of…
The brain and spinal cord
And is linked to sense organs by nerves.
Stimulations of receptors in the sense organs sends…
Electrical impulses along nerves into and out of the CNS, resulting in rapid responses.
Geotropic responses of roots and stems
stems: grow away from direction of gravity (negative geotropism)
roots: grow towards direction of gravity (positive geotropism)
Phototropism of stems
The stem grows towards light source (positive phototropism)
Tropisms
Reactions to the environment.
The difference between the nervous system and the endocrine system
nervous system:
Works by nerve impulses transmitted trough nerve cells
Nerve impulses travel fast and usually have an ‘instant effect’
Response is usually short-lived
Impulses act on individual cells
Endocrine:
Works by hormones transmitted through the bloodstream
Hormones travel more slowly and generally take longer to act
Response is usually longer-lasting
Hormones can have widespread effects on different organs
Pituitary gland sends out which hormones?
FSH (follicle stimulating hormone)
LH (luteinising hormone)
ADH (anti-diuretic hormone)
GH (growth hormone)
Thyroid sends out which hormones?
Thyroxin
Pancreas releases which hormones?
Insulin
Glucagon
The adrenal glands release which hormones?
Adrenaline
The testes release which hormone?
Testosterone
The ovaries release which hormones?
Oesteogen and progesterone
What happens to the body when adrenaline is produced?
Breathing rate increases (taking more oxygen in)
The heart beats faster (sending more blood to the muscles)
Blood is diverted away from the intestine and into the muscles
Stored carbs in the liver is turned into glucose and released into blood for respiration
Pupils dilate
Body hairs stand on end
Mental awareness is increased
