SPECIAL SENSES Flashcards
The _________(_) is responsible for motor control of the eye and constricting of the iris (PNS)
Occulomotor (3)
What nerve causes afferent impulses for vision?
Optic (2)
The trochlear (5) and abducens (6) control what?
Eyeball movement and proprioception
What causal nerve controls the lacrimal gland and is responsible for tears ?
Facal (7)
Nearly half of the __________ _______ is involved in processing visual information
Cerebral cortex
The eyebrows over lie the ___________ margins
Supra orbital
The eyelids protect the eye _______
Anteriorly
_______ is a transparent membrane of the eye
Conjunctiva
Tears drain into the_________ duct
nasolacrimal
Tears enter paired lacrimal______ via the lacrimal_____
canaliculi
puncta
How many extrinsic eye muscles are there?
6
4 rectus - originate from common tendinous ring; names indicate the movements they promote
2 oblique - move eye in verticals plane and rotate eyeball
The six strap like extrinsic eye muscles originate from the bony ______
orbit
The lateral rectus moves the eye _______ and is controlled by the ______ cranial nerve
Laterally
Abducens
The medial rectus moves the eye ________ and is controlled by the ________ nerve
Medially
laterally
The _______ _________ elevates the eye and turns it medially - it is controlled by the occulomotor nerve
superior rectus
The ______ ______ depresses the eye and turns it medially - It’s controlled by the occulomotor nerve
Inferior rectus
The inferior oblique muscle _______ the eye and turns it _________
Elevates
Laterally
The _______ ______ depresses the eye and turns it laterally - it is controlled by the ________ cranial nerve
superior oblique
Trochlear
How many layers is within the eyeball
3
What are there 3 layers of the eyeball
Fibrous
Vascular
Sensory
The outer most layer of the eyeball is …?
Fibrous
The outermost layer of the eyeball - the fibrous layer is divided into two regions: the ______ and the ________
Sclera (posterior portion) (the white layer)
Cornea (anterior) (the transparent layer)
What separates the internal cavity into interior and posterior segments (cavities)
The lens
What pumps of the corneal endothelium on the inner face help maintain the clarity of the cornea
Sodium
The ______ layer forms the middle part of the eyeball and has ____ sections
Vascular
3
The vascular layer of the eyeball is divided into three layers;
CCI
Choroid
Ciliary body
Iris
The _________ is a blood vessel rich, dark brown membrane. It’s vessels nourish the eye and prevent light scattering
choroid
Anteriorly the choroid becomes the ____________- a thickened ring if tissue that encircles the lens
Ciliary body
The _____ Is the visible colour of the eyeball
Iris
The muscle fibres if the _____ help it to act as a reflexively activated diaphragm to vary pupil size
Iris
The sphincter pupillae muscle contraction ________ pupil size and is p___________
Decreases
Parasympathetic
Dialator pupillae muscle contraction ______ pupil size and is _________
Increases
sympathetic
The iris consists of two muscles the ________ pupillae and the ______ pupillae
Sphincter
Dilator
The sensory layer of the eye includes the ______
retina
The retina consists of two layers:
The pigmented layer of the retina and the neural layer of the retina
The _____ layer of the retina is the pigmented layer
outer
The ________ inner _______ layer of the retina extends Anteriorly to the posterior margin if the ciliary body
transparent
neural
From posterior to anterior the neural layer is composed of three main types of neurons;
- P
- B
- G
Photoreceptors
Bipolar cells
Ganglion cells
The ______ disc is where the retina exits the eyeball
optic
______ dim light and peripheral vision receptors and are the most sensitive
Rods
______, by contrast are vision recruits for bright light and provide colour vision
Cones
____ cell axons run along the inner surface of the retina and leave the eye as the optic nerve
Ganglion
The lens is a halo like ciliary zonule that divides the eye into two segments. The anterior segment in front if the lens and the larger posterior segment behind it. The posterior segment is filled with a clear gel called ___________
Vitreous humour
The iris divides the anterior segment into the anterior chamber (between the cornea and the iris) and the posterior chamber (between the iris and the lens)
The entire anterior segment is filled with ______ humour
aqueous
______ humour of the anterior segment Is in constant motion and is similar composition to blood plasma
Aqueous
_______;Packets of energy called protons (quanta) that travel in a wave like fashion
Light
______ and _______ respond to different wavelengths of the visible spectrum
Rods and cones
Refraction occurs when light meets the surface of a different medium at an ________ angle
oblique
Pathway of light
________>________ humour>lens>_______ humour>neural layer of retina>photoreceptors
Cornea
aqueous
vitreous
Light is refracted
- At the ______
- Entering the lens
- Exiting the lens
cornea
Change in ______ curvature allows for fine focusing of an image
lens
The lens is ________ for distant vision
Flattened
___________ input relaxed the ciliary muscle, tightening the ciliary zonule and flattening the lens
Sympathetic
Close vision requires
Accommodation, __________ and ____________
Constriction and convergence
The lens bulges for close vision. ______________ input contacts the ciliary muscle, loosening the ciliary zonule, allowing the lens to bulge
Parasympathetic
The outer segments of rods and cones are embedded in the pigmented layer of the ______
retina
Rods are very sensitive to _____ light
Dim
_____need bright light got activation
Cones
The visual pigment of rods Is ______. When light is absorbed it breaks down
rhodopsin
There are three parts to the ear:
1
2
3
External (outer)
Middle ear (tympanic cavity)
Internal (inner) ear
The ______ ear and the _______ ear are involved with hearing
external
Middle
The _______ ear (lay birth) functions in both hearing and equilibrium
internal
The auricle (pinna) of the external ear is composed of the ______ and the _______
Helix
Lobule
The hole of the ear is called the ____________ acoustic ____________ (auditory canal)
External acoustic meatus
The boundary between the external and middle ear is termed the ___________ membrane
Tympanic membrane
The __________ is described as a small, air filled, muscoss lined cavity in the temporal bone
Middle ear
The ___________ (auditory tube) connects the middle ear to the nasopharynx
pharyngotympanic
The superior portion of the middle ear is termed the _________ recess
epitympanic
The 3 auditory ossicles are 3 small bones in tympanic cavity: the
M_______
I________
S________
Malleus (most medial - the hammer)
Incus
Stapes
The internal ear consists the bony labyrinth, _______ labyrinth
membranous
