Introduction to the nervous system Flashcards
How is the nervous system important in maintaining homeostasis
An organisms environment is always changing, some of these changes take place outside the body, some inside it. however the body must maintain a constant internal state despite changing external/internal conditions, this is called homeostasis. it is the role of the nervous system to detect and initiate a response towards such changes. the nervous system makes sure that a response is adequate and directed in the right place. nervous system also coordinates responses, that is it makes sure that they occur in the right order
What are the two systems of the nervous system
Peripheral and central systems
What are the two parts of the peripheral nervous system
the afferent (sensory) and efferent (motor)
What are the two parts of the efferent (motor)
the somatic nervous system and the autonomic nervous system
What are the two parts of the autonomic nervous system
Parasympathetic and sympathetic
What are the two parts of the central nervous system
the brain and spinal cord
What are the parts of the nervous system
Brain, spinal cord, nerves, receptors and effectors
What are nerves made of
cells called neurons
What are the three types of neurons
Sensory/afferent
Motor/efferent neurons
Interneurons
What are sensory/afferent neurons
carry impulses from receptors to the brain and spinal cord
What are motor/ efferent neurons
carry impulses from the brain and spinal cord to the effectors
What are interneurons
another name for these are associative neurons. these relay impulses between neurons in the brain and spinal cord. most abundant
What do receptors do
receive stimuli from inside and outside the body
example: pain receptors
What are effectors
the parts of the body that respond to messages sent out from the brain or spinal cord. these are muscles and glands, internal organs
What is impulse/action potential
a message carried by a neuron
What is a stimulus
anything that causes a receptor to start a nerve impulse
What are neurons
A nerve cell. the basic structural and functional unit of the nervous system
What is a reflex
an automatic, unthinking response to a stimulus
An example of reflex
If you touch a cactus spine, within an instant, your hand will spring away. the sharp spine activates the nerve ending in a pain receptor. an impulse travels along the sensory neuron to an interneuron in the spinal cord. In return the interneuron connects with a motor neuron that sends an impulse to a muscle (effector) in your hand. the muscle contracts and your hand pulls away. seconds later your brain determines what happens. reflexes serve an important protective function, they allow your body to react quickly, decreasing the danger of injury
