coordination and response Flashcards
which neurone gives the central nervous system information
sensory neurone
which neurone does the central nervous system send information out via
motor neurone
what is a reflex arc
the nerve pathway that follows a reflex action
what are the benefits of reflexes
rapid
automatic
what passes along nerve cells
electrical impulses
what is released across a synapse
chemicals
what is the role of a receptor
to detect a stimulus
what is the role of a sensory neurone
to transfer a signal from a receptor to the CNS
why are reflexes important
they protect us from harm
what are the small chemicals that glands release
hormones
in the endocrine system, where are the hormones released into
bloodstream
what do hormones bind to
specific cells that have the correct receptors
what is the role of thyroxine and where is it released
it regulates metabolism and is released in the thyroid gland
what is the role of adrenaline
stimulates fight or flight response
where is insulin released
pancreas
do the effects of the endocrine or the nervous system last longer
endocrine - hormones stay in the blood for a long time, electrical impulses last a split second
what does adrenaline do
increases heart rate
inreases blood pressure
increases blood flow to muscles
increase blood sugar levels
what are the three main components of an automatic control system
receptor
coordination centres
effector
definition of homeostasis
the regulation of conditions inside the body to maintain a stable internal environment in response to both internal and external conditions
what are automatic control systems
they recognise when conditions change from optimal conditions and send a signal to reverse the change
how are signals sent through automatic control systems
nervous system
endocrine system
why does the body need to maintain optimal conditions
for optimal enzyme action and cell function
what is the role of a receptor in homeostasis
detects change in internal/ external environment
what is the role of coordination centres in homeostasis
interprets change and organises response
name two effectors in homeostasis and what they do
muscles contract when stimulated
glands release hormones when stimulated
what is negative feedback
a system meaning that whenever the levels of something are too high they are brought back down and when the levels of something are too low they are brought back up
what is the temperature that the human body should be kept at and why
37 degrees
it is the optimum temperature for enzymes to function
what is thermoregulation
the control of our internal body temperature
where are the two main places where temperature receptors are found
skin
blood vessels
where is the thermoregulatory centre found in the body
the brain - hypothalamus
name some reactions the body will have in response to being too cold
vasoconstriction
hair standing up
less sweat released
shivering
name some reactions the body will have in response to being too hot
vasodilation
hair laying flat
more sweat released
how is information about skin temperature sent to the brain
the nervous system
how does shivering warm up the body
muscles relax and contract automatically
this requires a lot of energy from respiration, which in the process releases a lot of heat energy as waste
what is vasodilation
the arterioles supplying the capillaries near the surface of the skin get wider, increasing the flow of blood in the skin capillaries so more heat is lost by radiation
what is vasoconstriction
the arterioles supplying the capillaries near the surface of the skin get narrower, decreasing the flow of blood in the skin capillaries so less heat is lost by radiation
how is an involuntary action different to a voluntary action
involuntary is faster
its an automatic reflex - requires no thinking
the response is always the same
what causes shivering
muscle contraction
