Please enable JavaScript.
Coggle requires JavaScript to display documents.
Nervous System (Senses (the eye components and visual pathway (Posterior…
Nervous System
Senses
the types of receptors based on stimulus origin
Exteroceptors
our enviornment> skin, specialized senses, sight, hearing, taste, smell, equilibrium
Interoceptors
internal organs
proprioceptors
is muscle, their tendons, ligaments, and joints
the types of receptors based on stimulus type
Thermoreceptor
cold/ warm receptors
Photoreceptor
light
chemoreceptor
chemicals> nose, tongue, blood
Nocieceptor
pain
Mechanoreceptor
touch, pressure, vibration, stretch
Baroreceptor
blood pressure
the eye components and visual pathway
Fibrous Layer
Sclera
White; dense connective tissue, anchor for extrinsic eye muscles, protective, give shape
Cornea
transparent, allows light into eye, focus light
Vascular Layer
Choroid
Nourishes other layers, pigment absorbs light, prevents scattering
Inner layer
Retina
photoreceptors- axons from photoreceptors; converge to form optic nerve
Rods
most abundant; sensitive to light/ dark
Cones
color vision, best in bright light
Lens
Important for focusing light on the Retina
Iris
Anterior to lends- posterior to cornea; colored part of eye, intrinsic muscle, for dilation/contraction of pupil
Optic Disc
Blind spot> no photoreceptors
Macula Lutea
(part of retina)- exactly opposite the pupil, where you have clearest vision
Fovea Centralis
w/in macula lutea
Posterior Segment
Boundary:lens & ciliary body -> posterior wall
Filled w/ vitrous humor- transmits light, support retina & lens; maintains pressure w/in eye
iris to lens/ posterior segment
Anterior Segment
Lens to cornea- filled w/ aqueous humor
Light as it passes through the eye to retina
Cornea--focus> Lens->retina (photoreceptors)
Nerve impulses from retina to brain
retina-> optic Nerve->Optic Chiasma -> optic Tract-> thalmus-> primary visual cortex(in occipital lobe)
olfaction components and pathway
roof of nasal cavity, pseudociliated columnar epithelium w/ olfactory sensory neurons-> olfactory bulb-> olfactory tract
Olfatory tract
Limbic region- emotional brain
primary olfactory cortex in temporal lobe
gustation components and pathway
Taste buds:
Tongue, inner cheeks, pharynx, palate, epiglottis
(3) cranial Nerves
Facial Nerves CN7 2. Glossopharyngeal CN 9
Vagus CN 10
Receptor cells-> 3 cranial nerves-> medulla oblongatta-> thalamus-> primary gustatory cortex in the insula
ear components and pathway
External Ear
Aurricle/Pinna: gather, funnel sound waves and amplify
Middle Ear
Tympanic Membrane
Vibrates; transmits vibrations-> middle ear-> Auditory Ossicles
Auditory Ossicles
transmits vibrations-> cochlea-> cochlear nerve+ vestibular nerve-> vestibular cochlear nerve CN8 (sense of equilibrium)
Hearing Pathways
Cochlear nerve-> Medulla Oblongata-> pons-> midbrain-> thalamus-> primary auditory cortex on temporal lobe
Nervous System Organization
CNS main structures and functions
receive, process, respond to sensory input
Brain and Spinal Cord
White Matter
tracts in the brain & spinal cord
Grey Matter
cell bodies in the brain-cortex(outer layer)
PNS main structures and functions
cranial nerves& spinal nerves connected to brain,
gathers sensory information from receptors and passes it on to CNS
somatic division
Somatic Motor
Mainly skin, body walls/torso, skeletal muscles
everything except ventral body cavity contents
Somatic Sensory
Skin, skeletal muscles, joints; hearing equilibrium, vision
autonomic division
Autonomic Motor
Mainly ventral body cavity contents
Smooth muscle/of blood vessels, cardiac muscles, glands (inc. sweat), arrector pili muscles
Visceral sensory: mainly ventral body cavity; gustation and olfaction
Neurons
major components of a neuron
Cell body, nucleus,axon, terminal aborization, dendrites
Nucleolus
creates ribosomes
Chromatophilic substance
Dense region of rough endoplasmic reticulum & free ribosomes-> creates plasma membrane & other proteins
Axon collaterals
branch of axons from main axon
Axon Hillock
specialized part of the cell body of a neuron that connects to the axon
structural types of neurons
Multipolar
Bipolar
Unipolar
functional types of neurons
Motor (efferent neurons)
Signals away; multipolar
Sensory (afferent neurons)
unipolar
Interneurons (association neurons)
In CNS only- b/w neurons; multipolar
Anatomy of Nervous System
nerve components
axon
Myelin sheath: around some axons
endoneurium: loose connective tissue
bundle of axons: fascicle
perineurium: fibrous connective tissue
epineurium: tough fibrous connective tissue, surrounds all fascicles
glial cells
location/description
Astrocytes: most abundant, processes contact; supportive, helping maintain a proper chemical enviornment; axons and capillaries
Microglia
phagocyte- destroys invading microbes & damaged/dying nervous tissues
ependymal cells
Simple cuboidal/columnar epithelium w/ cilia & microvilli
satelilite cells
Location: surrounding cell bodies in ganglia
Function: supportive; help regulate what goes in/out of neuron cell bodies
Ogliodendrocytes
CNS myelination
Schwann Cells
PNS