2.2 control and communication Flashcards
why multicellular organisms need communication systems
a multicellular organism is made up of many cells that carry out a particular functions. A communication systems send materials around the body and send signals to different parts of the body so they are coordinated in their working
three internal communication systems
nervous system
endocrine system
Hormone system
three structures that make up the nervous system
brain
spinal cord
nerves
two structures that make up the CNS
spinal cord
brain
three main parts of the brain
medulla- controls vital functions like breaking and heart rate
cerebrum continues thoughts, problem solving, memories, personality
cerebellum- coordination balance
how is information transported across neurons
information is transmitted across neurones is electrical impulses
i can identify the tiny gaps that separate neurones from each-other
neurons do not have physical contact with each-other so the tiny gaps are made up of synapses
i can describe the role of chemicals in transmitting an electrical impulse
chemicals called neurotransmitters are released from the pre synaptic neurone and diffuse across the synapse to bind with a membrane receptor on the post synaptic neurone. When the neurotransmitters bind to its specific receptor an electrical impulse will be fired in the post synaptic neuron.
role of the CNS in processing and responding to information from the senses
sensory neurons pick up a stimulus and transmit an impulse to the CNS which contains the inter neurons- This is where the process will decide if the process is required or not. Many stimuli are detected by the CNS but not all are responded too, many are filtered out. If the CNS desides if the response is required another impulse will be sent out
two responses triggered by the motor neuron
muscle contraction to bring about movement
secretion from a gland releasing a chemical messenger
sequence involved in a reflex
sensory neuron- detects stimulus
inter neuron-
receives respond from sensory and sends it to motor
motor - carries the signal to bring about a response
function of reflex response and examples
reflex response is to protect the body against danger
- touching something hot AND quickly pulling hand away
- Stepping on soemthing sharp AND quickly lifting foot up
role of endocrine system
communication system that transmits and realises chemical messages around the body and in the blood called hormones to bring about response
organs in a endocrine system
adrenal glands - release of adrenaline
pancreas - release of insulin and glucagon
testes- release of testosterone
role of hormones around the body
hormones are chemical messangers (protein) that are released in the endocrine system and transmitted in the blood stream. They send messages to different cells/tissues and trigger specific responses
hormones target specific tissues in the body
hormones are proteins that have a specific shape. These are matched by complementary receptor proteins found in the membranes of the target cell/tissue/organ. when a specific hormone matched it’s specific receptor protein this triggers the cell to respond in a particular way
i can compare the nervous system and endocrine mesages sent
nerve
electrical impulses through nueron and diffusion of neurotransmitters across synapses
endocrine
chemical messangers in form of hormone transmitting in the bloodstream
speed of info transfer
nervous
very quickly compared to hormones
endocrine
very slow in comparison to nerve impulses
responses
fast over a short period of time response eg reflex
endocrine
slow over short period of time respond eg pubarty
improtant to keep body optimum temp
so chemical reactions happen efficiently as possible
homeostasis
make sure the internal environmental factors at a constant steady set point eg regulation of body temp and blood sugar levels
where are blood glucose levels monitored
pancreas
importance of controlling blood glucose levels
ensure the body always has a supply of glucose for respiration and to stop potential osmotic damage to cells
when is glucagon and insulin released from pancreas
glucagon is released when in response to the body have a decrease in blood glucose levels below set point
insulin is released when in response to body having a high blood glucose level above set point
