Studied by 2 people
coordination systems working together under fight or flight responses
nerve impulses stimulate adrenal gland to secrete adrenaline, which brings about the changes necessary for a fight or flight response
sensory neurone
carriees impulses from the sense organs to the CNS
endocrine system - hormones secreted by endocrine glands
slow action
sustained response
widespread response
long-term effects
nervous system - electrical signals along nerve cells
quick action
immediate response
localised response
short-term control
relay neurone
makes connections between sensory and motor neurones in the CNS
motor neurone
carries nerve impulse from CNS to effector muscles/gland to initiate a response
nerve impulse
travels in one direction only
synapse
a structure that permits a neurone to pass on an impulse to another nerve cell
neurotransmitters
chemical messengers released during synaptic transmission, initiate or inhibit a nerve impulse in the next cell
reflex action
an automatic and rapid response involving effectors, which is essential for survival
reflex actions are essential for survival because
they allow the animal to respond quickly to situations that might endanger it
2 neurone reflex arc (mallet hits tendon, causing it to stretch)
stimulus → receptor → sensory neurone → coordinator (spinal cord) → motor neurone → effector → response
cerebrum structure
2 cerebral hemispheres, each side controlling the opposite side of movement in the body.
inner layer = white matter = myelin sheaths.
outer layer = grey matter = cell bodies of neurones
→ highly folded to inc SA for more neurones + more neurone connections
3 neurone reflex arc (touching fire or pin)
stimulus → receptor →sensory neurone → coordinator (spinal cord) → relay neurone → motor neurone → effector → response
cerebrum functions
memory
intelligence
reasoning
acquired skills
consciousness
movement
cerebellum
coordinates movement
eg. balance (requires coordination between multiple part of body)
medulla oblangata/brain stem
responsible for autonomic (involuntary) actions
breathing rhythm
heart rate
swallowing
vasiconstriction/dilation
sneezing/vomiting
→ involve reflex actions influenced by nerve impulses from other parts of the brain
pituitary gland
master gland → controls other endocrine glands in the body, producies hormones that act as chemical messengers which stimulate other glands ie.
ADH (pituitary gland) targets collecting duct in kidney to absorb more water
FSH + LH (pituitary gland) target ovaries
hormones
chemicals produces by endocrine glands to bring about a response by a target organ or cells
endocrine/hormone-secreting glands are ductless glands…
hormones are secreted directly into the blood and not through ducts
pancreatic hormones
regulate blood glucose levels (homeostasis)
insulin and glucagon
are antagonistic hormones
target the liver
when blood glucose levels aretoo high
Islets of Langerhans produce insulin, targeting the liver and muscle cells to bring down/restore glucose conc.
insulin functions
stimulates cells to take in glucose from the bloodstream (liver & muscle cells)
excess glucose is converted into glycogen for storage in liver and muscle cells
promotes conversion of carbs to fats and slows down conversion of proteins to carbs
when blood glucose levels are too low
Islets of Langerhans produce glucagonto bring back up/restore glucose levels to normal
function of glucagon
acts on liver cells and causes them to convert stored glycogen into glucosenega
negative feedback
involves detecting that a level of a substance or a condition has gone above/below normal levels, which triggers a response to bring back the level to the set point again through the use of 2 opposing systems (antagonistic hormones)
using regulation of blood glucose levels as an example of negative feedback
glucagon - increases blood glucose levels when conc. is low
insulin - decreases blood glucose levels when conc. is high.
Note 
Flashcard (59)