Anatomy 9a CN1-6 Flashcards
If olfaction a mechanical or chemical receptor?
Chemical
T/F Olfactory receptor cells are neurons in the nasal cavity
True
What bone is the roof of the nasal cavity?
Ethmoid Bone
Which hair system IS neurons:
Olfactory
Cochlea
Vestibular
Olfactory
Describe the olfactory sensory/receptor cells (hair cells) found in the sensory organ olfactory epithelium
(What type of neuron)
Bipolar neurons with cilia (olfactory hairs) on end of dendrite
What are the supporting cells found in the olfactory epithelium?
Mucous membrane lining of nasal cavity that function to support, nourish, insulate, and detoxify olfactory receptor cells (neuroglia)
What are the basal stem cells found in the olfactory epithelium?
Neurons continually undergoing replication to replace olfactory receptor cells which have a life span of 1 month
What are the olfactory glands found in the olfactory epithelium?
Provide mucous to cover surface of olfactory epithelium to dissolve odor molecules so they can interact with receptor cells
T/F: Odor molecules must be dissolved before they can interact with olfactory sensory/receptor cell receptors
True
What is adaption in regard to olfactory apparatus?
Process by which we decrease our sensitivity to continuous exposure to a particular odor (50% adaptation in first second of exposure)
Describe the olfactory pathways starting with an odor ending at olfactory bulb
Odor (molecule in air) -> molecule dissolves in mucous of nasal surface -> molecules binds to combination of olfactory receptors protein (ligand binding) -> Chemical gated channels open (Ca/Cl) -> Depolarize due to graded potential on dendrite/soma in olfactory epithelium (CN 1 not considered ganglia) -> AP down axon CN 1 -> CN 1 goes through cribriform plate to olfactory bulb
T/F: Olfactory bulb is layered for processing signals and is NOT topographically representative of olfactory epithelium for discriminating signals
F:
IS topographically representative of olfactory epithelium for discriminating signals
T/F: Olfactory bulb does not always send signals
False: Olfactory bulb is always sending signals and a new signal changes the pattern of signaling
Olfactory tract carries new pattern of signals from olfactory bulb to:
- Ipsi and contralateral limbic structures (amygdale, entorhinal cortex, hippocampus, prefrontal cortex, Insula (reflex to odor)
- Temporal? either directly or via thalamus for odor discrimination
What are the 5 accessory structures of the eye?
Eye lid Eye brow eye lashes muscles lacrimal apparatus
Eye lid:
Function:
What muscles close lid and what CN?
What is the inner lining of eye lid?
- Function - protect eye
- Orbicularis occuli orbital and palpebral close eye (CN 7)
- Palpebral conjunctiva is the inner lining of eye lid (continuous with sclera)
What is the lacrimal apparatus?
Describe pathway
- Lacrimal glands produce lacrimal fluid (tears) which is released (CN 7)
- Secrete fluid superior/lateral -> flows diagonally to inferior/medial lacrimal canals-> empty into nasal cavity
What are the extrinsic eye muscles? (6)
Superior/inferior rectus
lateral/medial rectus
superior/inferior oblique
What is the sclera of the eye?
Continuous with what?
Avascular/vascular?
- Continuous with the cornea
- Forms an AVASCULAR dense “white” CT covering the eye
The sclera of the eye for an attachment between eye and what 3 structurs?
- Palpebral conjunctiva of eye lid to close off eye socket
- Dural sheath (epineurium) of CN 2
- Tendons of extraoccular muscles
- > Effectively hold eye in place
What is the cornea?
Avascular/vascular?
AVASCULAR area covers anterior surface of eye ball
The vascular middle layer of the eye is called what?
Uveal tract
What is the choroid of the eye?
Middle layer
Contains blood vessels
What is the ciliary body of eye?
Anterior modification of choroid
What is the ciliary processes of ciliary body?
What does it produce?
What does it attach to?
- Form circular ridge
- Contains capillaries
- Produce aqueous humor
- Attach to suspensory ligaments which connect to lens
Ciliary muscle:
What is it?
What CN innervation?
- Circular smooth muscle at base of ciliary process that changes shape of lens by pulling suspensory ligaments (visual accommodation for near/far vision)
- CN3 parasympathetic innervation
Describe what happens when ciliary muscle contracts?
Increase/decrease CN stimulation?
Decrease tension of lense -> convex surface (opening decreases) -> near vision
-Increase CN 3 stimulation
Describe what happens when ciliary muscle relaxes?
Increase/decrease CN stimulation?
Increase tension of lense -> flat surface (opening increases) -> far vision
-Decrease CN 3 stimulation
What is the iris?
- Area of eye color
- Smooth muscle fibers that change size of opening (pupil) through which light enters eye ball
The circular muscle of the iris does what?
Innervated by?
- Constricts pupil
- Parasympathetic CN 3
The radial muscle of the iris does what?
Innervated by?
- Dilate the pupil
- Sympathetic (carotid plexus/sup cervical plexus)
What is the retina?
- Inner layer
- Contains neuron sensor receptor cells and is beginning of visual pathway
What is the pigment epithelium of retina?
Neural/non-neural epithelial cells?
- Outer layer of retina next to choroid
- Composed of non-neural pigmented epithelial cells
What is the photoreceptor layer of retina?
Rods-
Cones-
-Neurons contain sensor receptor processes with photo-pigment
Rods - dim light vision produces gray images (100 million/retina)
Cones - bright light vision produces color images (5 million/retina)
What is the outer nuclear layer of retina?
Soma of rods and cones
The outer synaptic layer of retina is also called?
outer plexiform layer
What is the inner nuclear layer of retina?
Bipolar layer for initial image processing
What is the ganglion cell layer of retina?
- Bodies of ganglia cells (multipolar ganglia cells NOT pseudounipolar)
- Axons of ganglia cells form optic nerve fibers (inner most layer of the retina next to vitrous body)