Homeostasis, endocrine system, nervous system Flashcards
Definition of homeostasis
Regulation of the internal condition of an organism to maintain optimum conditions for enzymes to work properly
What is an effector
Muscles or glands that bring out responses
What is cordination Centre
Receives processes information and coordinates responses
What is a stimulus
Change in the environment
What is a receptor
Detects change in the environment
What is the CNS
Central nerve system
What are the two main parts of a nervous system
A series of nerves and the CNS
How is the information sent in the nervous system
As an electrical impulse
What does an electrical impulse pass through
The sensory receptor along the sensory neuron to the CNS then passes along a relay neuron in the spinal cord and straight back down along a motor neuron from that the impulse arrives in the sector organ usually a muscle and brings about a contraction we call this a reflex arc
What is a reflex arc
One in electrical impulse passes from the sensory receptor along the sensory neuron to the CNS then pass it along a relay neuron usually found in the spinal cord and straight back down along and motor neuron from there the impulse arrives at an affecter on organ usually a muscle and brings about a contraction
Why is it so important that the impulses do not go to the conscious brain
Because the brain does not process these reflexes quick enough
What is the function of a sensory neuron
Carries the electrical impulses from the receptor and passes through cells called neurons to the CNS
What is the function of a motor neuron
Carries electrical impulses from the CNS to the effector
What is the function of a relay neuron
It carries the electrical pulse from the sensory nerve cell to the motor nerve of cell
How does an electrical impulse passes through a gap between two neurons
An electrical impulse arrives hits the sacs containing chemicals chemicals go through to the receptor they attach to the receptor a new electrical impulses generated a new one is passed through
Examples of homeostasis
Controlling blood glucose
Controlling body temp
Controlling water levels
What is the negative feedback loop
Stimulus
Sensor
Control
Effector
What is the body temp regulation loop
Body temp exceeds 37^c
Nerve cells in skin and brain
Temp regulatory centre in brain
Sweet glands throughout body
What is the control system
Stimulus
Receptor
Coordination
Efrector
Response
What are the parts of a nerve cell
Dendrite
Cell body
Nucleus
Axon
What are the three different types of neurones and there functions
Sensory neurone: carries nerve impulses from receptor to coordinator
Relay neurone: carries nerve impulses in coordinator
Motor neurone: carries nerve impulses from coordinator to effector
What are the parts of the synapses
Synaptic cleft
Vesicles contains neurotransmitter
Presynaptic membrane
Postsynaptic membrane
Neurotransmitter receptor molecules
What can drugs do to neurotransmitter
Can bind to them triggering impulses in different regions of the brain
What can frequent drug use lead to
Leads to overstimulating of neurones, leading to loss of function or overstimulation of different regions of the body
What is the synaptic transmition
1) an impulse arrives at the end of the presynaptic neurone
2) vesicles move toward and fuse with the presynaptic membrane this releases neurotransmitter into the synaptic cleft
3) the neurotransmitter diffuse across the synaptic cleft (down a concentration gradient)
4) neurotransmitter attach to receptors on the postsynaptic membrane
5) this triggers an impulse which travels along the postsynaptic neurone
6) the neurotransmitter are recycled or destroyed once an impulse is sent
What is reflex action
Does not involve consciousness so brain is not involved
Awareness of response having happened occurs after response has been carrried out these actions help to minimise damage to body
Apart from receiving nerve impulses via the nervous system how else can the effector be notified of what to do
Stimulus
Receptor
Coordinator
Effector
Response
What is the endocrine system
It is composed of glands which secrete hormones into the blood, blood carries the hormones to the effector to produce a response
What are the differences between endocrine system and nervous system
Hormones have a slower effect in the endocrine system as the nerve impulses have a quicker effect in the nervous system
Hormones act for longer in endocrine system in nervous system the nerve impulses act for shorter
What glands are in the endocrine system and what hormones do they produce
Thyroid gland- thyroxine
Pituitary gland- FSH,LH
Pancreas- insulin glucose
Adrenal- Adrenalin
Testes-testosterone
Ovaries- oestrogen
What is the master gland in the endocrine system and how does it work
The pituitary gland in the brain secretes hormones into blood to stimulate other hormones to be released from other glands. Example, pituitary gland secretes, TSH, which stimulates thyroid to release thyroxine
Four stages of the menstrual cycle
Uterine lining breaks down menstruation occurs
Uterine lining thickens again
Ovulation occurs
Uterine lining continues to thicken
How long is the menstrual cycle
28 days
What are the four hormones in the menstrual cycle
FSH
LH
Oestrogen
Progesterone
What is synaptic transmission
An impulse arrives at the end of the presynaptic neuron vesical move towards and fuse was the presynaptic membrane. This releases neurotransmitter into the synaptic cleft the neurotransmitter diffuse across the synaptic cleft neurotransmitter attached are receptors on the postsynaptic neuron, the neurotransmitter are recycled or destroyed once an impulse is sent
What does synapse mean
Where 2 nerve cells meet
What do vesicles contain
Neurotransmitter
