Coordination Flashcards
What are the events in the path of a coordinated response and explain each response
Stimulus–> Receptor–> Coordination–> Effector–> Response
Stimulus- is a change in surroundings of an organism that produces a response
Receptor- A cell or an organ that detects the stimulus by changing the energy of the stimulus into electrical energy in nerve impulses
Coordination- links receptor and effector organs
Effector-organ such as muscles or glands that bring a response
Response- reaction by an organism to stimulus
What are the 2 coordination systems in our body
Nervous coordination system- CNS and peripheral nervous systems
Chemical coordination system (endocrine system)- endocrine glands
What are 4 differences between nervous and hormonal responses
Nervous works by nerve impulses transmitted through nerve cells while endocrine works by hormones transmitted through the bloodstream
In nervous, nerve impulses travel fast and have an instant effect while in endocrine, hormones travel more slowly and take longer to act
Nervous has short lived responses while endocrine has long lived responses
In nervous, impulses act on individual cells such as muscle fibres, so they have a localised effect. In endocrine, hormones can have widespread effect on different organs
What does the CNS consist of
Brain, nerves, spinal cord
What does the endocrine system consist of
Pituitary gland, Thyroid gland, Adrenal gland, Pancreas, Ovaries/uterus, Prostate/Testes
Nerve impulses in the CNS
Nerve impulse travels along the neuron as an electric impulse, by movement of charged particles in and out of the neuron
CNS receives impulses from 5 senses or receptors (sight, sound, touch, taste, smell) through sensory neurons and transmit impulses to effector organs (muscle or gland) through motor neurons
Structure of a neuron
Has cell body and cytoplasmic extensions called dendrons and axons.
Dendrons receive impulses and direct it toward the cell body
Axon pass impulses away from the cell body
Long fibres are covered in myelin sheath to speed up conduction of impulses and insulating the axon to prevent short circuit with other axons
Neurons arent connected to each other and there are microscopic gaps called synapses
sensory neuron
Long dendron, short axon, cell body is in side branch
Carries impulses from sense organs to CNS
Motor neurons
Short dendron, long axon, cell body is at one side of the fibre in the CNS
Carries impulse from CNS to effector
Contains dendrons and dendrites to receive impulse
Relay neuron
Short neuron, axon and dendron same length
Found in CNS and carries impulses from sensory to motor neurons
The synapse
Gap between 2 nerve cells
Electrical impulses dont travel across the synapse, and it is always by a chemical called neurotransmitter
As synapses are crossed by chemicals, it is easier for other chemicals to interfere with the neurotransmitters
What are the sequence of events happening at a synapse
Electrical impulse at the end of the first neuron triggers to release a chemical called neurotransmitter
Neurotransmitter diffuses across the synapse and binds to the receptors on the membrane of the second neuron and this stimulates a electrical impulse in the second neuron
After the neurotransmitter has passed on the message, it is broken down by enzyme from the second neuron
What does the synapse ensure
Synapses ensure that impulses travel in only one direction, avoiding confusion with the nervous system if impulses were travelling in both directions
What is a reflex action
it is rapid , automatic or involuntary
It often protects the body
Reflex action involves the spine as the coordinator instead of the brain so reaction is fast
The reflex arc
