13 Flashcards
what 2 ways do animals communicate
*chemical - using hormones
electrical - using neurones
internal changes?
*Water potential
*Cell pH
*Glucose level
*Internal temp
external changes
*Light
*External temp
*New or sudden sound
*Humidity
why is coordination important?
organisms evolve and therefore certain cells may become specialised. The organism will need to coordinate these cells and systems to operate effectively.
coordination example
RBC carries O2 but relies on stem cells for RBC reproduction as RBCs dont have nucleus. However, stem cells are unable to respire and produce RBCs w/o O2. Therefore RBCs and stem cells work in coordination.
Homeostasis
The maintenance of relatively constant conditions in the body.
homeostasis p2
communication and coordination allows us to maintain homeostasis
cell signalling
*Neurotransmitters between neurones signal locally
*Hormones transfer signals across larger areas
plants signalling
use hormones to respond to stimuli e.g growth toward light
Neurones?
specialised cells that transmit electrical receptors
synapse?
The gap between 2 nerve cells in which neurotransmitters are used to transfer the signal
Reflex arc (refresher)
1 - stimulus
2 - receptor
3 - sensory neurone
4 - synapse
5 - relay neurone
6 - synapse
7 - motor neurone
8 - effector
what do nerve cells do?
transmit impulses from relay or sensory neurones to effectors such as muscles or glands
Sensory neurone
Transmits signals from sensory neurone to relay neurones, motor neurones and Brain
Relay neurone
Transfer impulses between neurones
*also called interneuron