Nervous System and Special Senses

Chapters 9 -  11

Cerebral cortex -  conscious mine and motor control

 Cerebral white matter – communication between cerebral cortex and lower CNS centers

 Basal nuclei – regulating attention and cognition, inhibits unnecessary movements

 Thalamus relays and edits signals

 Hypothalamus – visceral control center of body, helps overall homeostasis

 Brainstem – contains midbrain, pons, and medulla oblongata

 Midbrain – reticular activating system ---- filters info, helps you be awake

  Medulla oblongata –respiratory centers, cardiovascular centers

 Cerebellum – coordination of movements

 Limbic system – seat of the emotions

 Psychosomatic illness – stress stimulates parts of brain that cause symptoms of illness

 Narcolepsy – falling suddenly to sleep

 Insomnia – can’t fall asleep

 Sleep apnea – stop breathing during sleep

cerebral palsy – caused by lack of oxygen, usually during delivery

 spina bifida – incomplete formation of vertebral column, usually caused by lack of folate in diet

  spinal reflexes – do not require brain participation, example – pulling hand from hot stove

  Referred pain – pain that seems to be coming from one area but actually originates from another area due to shared nervous pathways

Learn Table page 325

Taste buds have chemical receptors that bind to molecules that cause sensations of tastes.

Olfactory cells – modified neurons in nose that detect chemicals that are interpreted in the brain as smell

 Olfactory fatigue – sensory adaptation to smell

 Cataracts – the lens becomes opaque and blocks light transmission

 Retinal detachment – retina comes loose from back of eye,   immediate emergency, can save vision if treated immediately, first sign may be blindness in top half of visual field

 Photoreceptors

                Rods – black and white vision, night vision

                Cones – color vision

 Color blindness – carried on sex chromosome, usually only males get it

 Nearsightness—eyeball is physically too long, only can focus on close objects

Farsightness – eyeball is physically too short, only can focus on far objects

Astigmatism  -- eyes focus on different planes

Depth perception is possible because both eyes focus on slightly different angles and the brain puts it all together

Hearing -- Sound wave vibrate tympanic membrane, it vibrates earbones, (malleus, incus, stapes) this vibrates inner ear, stimulates tiny hairlike nerve fibers which send signals to brain and are interpreted as sound

 Balance – semicircular canals in ear are filled with fluid.   Tiny hairlike nerve endings sense change in position of head.

 Nystagmus -  eye movement after rotation due to reflex set off by vestibular system

 Motion sickness is caused by sensory imbalance