Nervous System 4 Flashcards
Sensory neurons have structures that response to a stimulus are called
Receptors
What are connected to the neuron by dendrites
Receptors
What are the two type of senses
General and special senses
What type of sense is the receptors for these are widely distributed throughout the body: example skin organs joints
General senses
What type of sense are specialized receptors that are confined to structures in the head ex: eyes ears
Special senses
The stimulation of a receptor results in an action potential, impulses are carried from the PNS by afferent (sensory) neurons toward the CNS, the CNS analyzes and interprets the impulses
Sensory impulses
Are all nerve impulses (action potentials) that travel from a sensory receptor to the CNS the same??
Yes
The part of the cerebral cortex that receives the impulse determines
What the sensation is
The intensity (strength) of a stimulus is interpreted in the brain by
The rate ( frequancy) of the Impulses (action potential) reaching the brain
If a stimulus is constant for a period of time then
A receptor may or will adapt
In adaptive response what adapts quickly. Ie touch, temp. Receptors»
Not feeling your clothes
Phasic adaptors
In adaptive response what adapts slowly or not at all ie pain receptors
Tonic adaptors
Chemoreceptors, nocireceptors, photoreceptors, thermoreceptors, mechanorecptors are
Types of receptors
What receptor type respond to changes in chemical substances - smell, taste, oxygen levels
Chemoreceptors
What receptor type respond to tissue damage from: mechanical, electrical, thermal, chemical
Nocireceptors (pain)
What receptor type respond to light energy
Photoreceptors
What receptor type respond to the Changes in temperature
Thermoreceptors
Proprioreceptors, barorecptors, and stretch receptors are three types of
Mechanorecptors
What mechanorecptor respond to change in positions
Propriorecptors
What mechanorecptor respond to change in pressure
Barorecptors
What mechanorecptor are used in organs and muscles
Stretch receptors
Receptors for the _______ are widely distributed throughout the body
General senses
Exteroreceptive and visceroreceptivre are what type of senses
General senses
What general sense changes occurring at the bodies surfaces
Exteroreceptive
What general sense changes occurring in the viscera (organs)
Visceroreceptivre
What type of senses are smell, taste, hearing, equilibrium, and sight
Special senses
What is the organ of hearing
The ear
Of the hearing sense what is the section of the ear that external structures to tympanic membrane (eardrums) and gathers and transmits sound vibrations to internal structures
Outer section
Of the hearing sense what is the section of the ear is a air filled cavity within the temporal bone of the skull also contains 3 auditory ossicles malleus, incus, stapes and transmit & amplifies sound vibrations to the inner ear
Middle section
Of the hearing sense what is the section of the ear is the system of inter- communicating chambers
Inner section
Of the inner section of the hear what functions in hearing
Cochlea
Of the inner section of the hear what functions in equilibrium
Semicircular canals, and vestibule
- Sound waves enter external ear.
- Sound pressures cause tympanic membrane to produce vibrations.
- Auditory ossicles amplify and transmit vibrations to the cochlea.
- Specialized receptor cells (hair cells) in the cochlea respond to different frequencies of vibrations.
- Hair cells respond by releasing neurotransmitters.
- Neurotransmitters stimulate sensory neurons in cranial nerve VII.
- Impulses travel along the cranial nerve VII to the auditory cortex in temporal lobe for interpretation are
Mechanism of hearing
Of the static equilibrium the _____ senses the position of head when body is NOT moving also has specialized receptor cells (hair cells)
Vestibule
Of the dynamic equilibrium the ______ senses rotation and movement of head body, has three canals at right angles, has specialized receptor cells (hair cells)
Semicircular
The function of visual receptors located in the eyes also termed photoreceptors
Sight
Eyelids, lacrimal apparatus, and extrinsic ocular muscles are the _______ of sight
Accessory organs
In sight what is performed by the visual cortex in the occipital lobes
Interpretation of visual stimuli
In the outer layer of eye what is anterior 1/6, bulges outward and transparent due to lack of blood vessels and the extremely regular pattern of the connective tissue fibers also helps focus entering light
Cornea
In the outer layer of the eye what is posterior 5/6, white portion of the eye, protects the eye, attachment site for extrinsic muscles
Sclera
In the middle layer of the eye what contains the ciliary muscles & ciliary process • suspensory ligaments off the ciliary process hold the lens in place
Ciliary body
Of the middle layer of the eye a thin diaphragm of connective tissue and smooth muscles , the color portion of the eye, the pupil- center opening
Iris
In the inner layer of the eye what contains the visual receptors, continuos with the optic nerve, dense capillary network
Retina
In the inner layer of the eye the central region of the retina, produces the sharpest vision
Macula lutea
Of the inner layer of the eye it’s medial to macula lutea, nerve fibers leave the eye and become part of the optic nerve, does not contain receptor cells (blind spot)
Optic disc
Photoreceptors are modified neurons two distinct types
Rods
Cones
What photoreceptor have long, thin projections at their terminal , contains light- sensitive visual pigments, more sensitive to light than comes, also produce colorless vision
Rods
What photoreceptor have short, blunt projections at their terminal end, produce sharp images, responsible for the color in vision
Cones
Of the photoreceptor in cones what depends upon which set of cones the light from an image stimulates
Color perceived
