Chapter 35 Nervous system Unit 10 :
Tissue Types: Epithelial Connective Muscle Nervous
Epithelial tissue = covers & protects or secretes (glands)
Connective tissue = provides structure
Muscle tissue = creates movement
Nervous tissue = transmits impulses
Functioning Unit Neuron = nerve cell Star-shaped cell with numerous processes that conduct impulses
Divisions of Nervous system Central Nervous System Includes brain & spinal cord
Divisions of Nervous system Peripheral = includes nerves leading to & from the central nervous system –Cranial nerves = brain (to or from) head & face –Spinal nerves = spinal cord (to or from) skin & muscles Autonomic nerves = spinal cord (to or from) internal organs under involuntary control
Interneuron
“wide with fright” “heavy breathing” heart beats faster “butterflies” in stomach “white as a ghost”
The Brain Brain stem = includes medulla & pons –Controls involuntary actions & internal organs Cerebellum –Controls balance & coordination (posture & muscle tone) Cerebrum –Controls voluntary actions, the senses, intelligence, emotion & memory
The Senses Taste receptors in taste buds of tongue –Sweet, sour,bitter, salt Smell receptors in upper nasal cavity –Gaseous stimulation Touch receptors in skin, etc –Touch, pressure, heat, cold
The Ear Auditory canal = vibrations pass through to… Tympanic membrane (eardrum) 3 ossicles = hammer, anvil, stirrup Cochlea = fluid-filled spiral with nerve endings that are sensitive to vibrations Auditory nerve = carries information to brain Semicircular canals = for equilibrium Eustachian tubes = (to mouth) balances pressure
The Eye Cornea = light containing images passes through… Iris (with pupil) = colored muscle to regulate light Lens = behind pupil; to focus image on… Retina = receives image on fovea (focal point) –Cones = sensitive to light –Rods = functions without light Optic nerve = carries information to brain