Nervous System Flashcards
why is the nervous system important
allows our bodies to respond to the environment
what are the 2 nervous system types
- the central nervous system
- the peripheral nervous system
what forms the central nervous system
the brain and spinal cord
what forms the PNS
the nerves that connect the spinal cord to the rest of the body
what does the CNS do
controls most of the functions and responses in the body
what does the PNS do?
it forms the somatic nervous system which detects & responds to stimulus outside the body
how do we respond to an environment
can be voluntary or involuntary
how does a response work
- receptors detect stimulus
- impulse sent along the sensory neutron to the spinal cords
- CNS integrates the information and sends to the brain if necessary for processing prior to initiating a response
- impulse is sent from the CNS along the motor neuron to effector
- effector generates response
what is an effector
glands or muscles (things that cause response)
what is the autonomic nervous system apart of
the PNS
what regulates the autonomic nervous system
hypothalamus
what is the ANS made up of
parasympathetic
sympathetic
what happens in the parasympathetic
eyes - constrict pupil
salivary glands - stimulates salivation
heart - slows heartbeat
lungs - constrict bronchi
stomach - stimulates digestion
liver - stimulates bile release
intestines - stimulates peristalsis and secretion
bladder - contracts bladder
what happens in the sympathetic
eyes - dilate pupil
salivary glands - inhibit salivation
heart - accelerates heartbeat
lungs - dilates bronchi
stomach - inhibits digestion
liver - stimulates glucose release
kidneys - stimulates epinephrine and norepinephrine release
intestines - inhibits peristalsis and secretion
bladder - relaxes the bladder
what do the sensory organs do
play a vital role in the system, sensing changes to the environment surrounding the animal
what are the types of receptors
chemoreceptor
thermoreceptor
mechanoreceptor
photoreceptor
what are receptors
they detect stimuli and change due to stimuli, they can lead to action potentials in sensory neurons that are attached
what are the sense receptors
auditory
somatosensory
olfactory
gustatory
visual
what’s the somatosensory receptor
the skin contains variety of receptors which respond to the temperature, touch, pressure (whiskers contribute)
what’s the olfactory receptor
in the nasal cavity respond to odour molecules in the air, some animals have a Jacobsons organ which detects moisture borne odour molecules using the flehmens
what’s the gustatory receptor
tongue of many animals contain papillae which have taste buds, they respond to chemicals in food and drink to give sensations of taste - not all animals perceive taste the same way
what’s the visual receptor
photoreceptors in the retinal layer of the eye respond to the light
what’s the auditory receptor
hair cells in the inner ear vibrate according to the pitch and volume of sounds, they send impulses via auditory nerve to brain for processing
how do the receptors work in the eye
they are sensitive to light stimuli and send visual signals to the brain through the nervous system
describe the cornea and the purpose
its the transparent covering on the eye and it protects the eye, helping converge light rays that enter the eye