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381 Cards in this Set
- Front
- Back
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Chamber between cornea and iris
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Anterior chamber
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Chamber between iris and lens/zonule fibers
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Posterior chamber
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What fills the anterior and posterior chambers
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aqueous humor
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What the optic stalk forms from
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Outgrowth of embryonic forebrain
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When the optic bulb invaginates to form the optic cup, what do the inner and outer layers form?
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Inner: neural retina
Outer: Retinal pigmented epithelium |
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What is the lens vesicle formed from?
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Lens placode invagination
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What is the corneal epithelium formed from?
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Lens placode
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What is the outer fibrous tunic?
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Corneoscleral tunic
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What is the function/characteristics of the cornea?
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Transparent
Refraction |
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What is the function/characteristics of the sclera?
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Opaque/white
Structural support& muscle insertion |
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What is the vascular tunic? What 3 structures are associated with it?
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Uvea = vascular tunic
Choroid, Ciliary body, iris |
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What is the function of the ciliary body?
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Visual accommodation
Aqueous humor production |
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What is the function of the iris?
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Light regulation
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What is the neural retina?
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Sensory layer
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What are the characteristics of the choroid?
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Back 1/3 of uvea
Highly pigmented |
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Is the cornea vascular or avascular?
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Avascular
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What are the 5 layers associated with the cornea?
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Stratified squamous epithelium
Bowman's membrane Substantia propia (Stroma) Decemet's membrane Endothelium |
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Is the stratified squamous epithelium of the cornea keratinized or non keratinized?
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Nonkeratinized
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What is the stratified squamous epithelium of the cornea continuous with?
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Bulbar conjunctiva
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What are the surface cells of the corneal epithelium covered with?
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Microvilli
3 layered precorneal tear film for protection |
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What is the tear film of the corneal epithelium secreted by?
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Conjunctiva and eyelid glands
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Is the stratified squamous epithelium of the cornea innervated by nerves?
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Yes highly innervated by free nerve endings
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What is Bowman's membrane formed from?
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Tightly packed collagen fibers
Acellular |
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Where does Bowman's membrane end?
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Limbus
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What is the order/make up of the stroma?
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Highly ordered lamellae
Evenly spaced collagen fibers with keratinocytes (fibroblasts) between them |
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How are the layers of the stroma oriented?
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90 degrees to one another
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What are corneal proteoglycans?
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Protein bound sulfated glycosaminoglycans
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What is Decemet's membrane?
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A modified basal lamina in the Cornea
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What changes about the Decemet's membrane as one ages?
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The thickness increases
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What is the structure/arrangement of the endothelium in the cornea?
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Single layer----cuboidal cells
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What are 2 functions of the endothelium of the cornea?
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-Maintain hydration of cornea by actively pumping out salt ions and water
-Maintains transparency |
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Is the endothelium of the cornea self renewing or non-renewing?
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Non-renewing
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What are the layers of the sclera?
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Episcleral layer
Substantia propia Suprachoroid lamina |
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What is the loose connective tissue layer of the sclera?
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Episcleral layer
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What is the substantia propria/ Tennon's capsule of the sclera?
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Opaque/ white of the eye
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What is the arrangement of the substantia propia/Tennon's capsule of the sclera?
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Dense irregular connective tissue
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What is the substantia propia/Tennon's capsule of the sclera continous with?
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Corneal stroma & dura mater of optic nerve
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Where do extra ocular muscles insert?
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Sclera
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Is the stroma vascular or avascular?
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Vascular (some vessels)
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What is the anterior surface of the stroma covered with?
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Bulbar conjunctiva
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What provides support and protection for the inner eye layers?
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Sclera
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What is the limbus?
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Corneoscleral junction
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What two things are continous at the corneoscleral junction/limbus?
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Corneal epithelium and epithelium of bulbar conjunctiva
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What two things merge at the limbus?
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Dense irregular tissue of sclera and highly ordered collagen of cornea
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Where are the Canal of Schlemm and trabecular meshwork located?
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Limbus/Corneoscleral junction
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What is the lamina cribrosa and where is it located?
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Location: posterior portion of eye
Allows the optic nerve to exit through sclera |
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Where does the choroid of the uvea extend?
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From optic nerve to ora serrata
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What is the structure of the choroid of the uvea?
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Loose, highly vascular CT with melanocytes
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What are the 3 layers of the choroid?
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Outer layer
Middle Layer Inner layer/Choriocapillaris |
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Where are the large blood vessels of the choroid located?
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Outer Layer
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What layer provides nutrients to the retinal layer?
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Choriocapillaris (Inner layer)
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What two layers combine to form Bruch's membrane?
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Choroid capillary endothelium
Retinal pigmented epithelium Collagen and elastic fibers |
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What binds the choroid to the pigmented epithelium of the retina?
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Bruch's membrane
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What insures a blood supply to the outer retinal layers?
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Bruch's membrane
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What are the boundaries of the ciliary body?
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Limbus to ora serrata
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What is the ciliary body continuous with?
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Iridial stroma and choroid of uvea
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What is the structure of the ciliary body?
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-(Stroma)Loose connective tissue with melanocytes
- Double layer of cuboidal epithelium |
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Is the ciliary body vascular or avascular?
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Vascular
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What is the deep pigmented layer of the ciliary body an extension of?
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Retinal pigmented epithelium
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Is the surface layer of the ciliary body pigmented or non-pigmented?
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Non-pigemented
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What is the flattened region of the ciliary body that is continuous with the sensory retina?
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Pars plana
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What are the fingerlike processes with a vascular connective tissue core of the ciliary body?
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Ciliary processes
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Are the ciliary processes vascular or avascular?
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Vascular (fenestrated cappillaries)
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What covers the ciliary processes and what is their function?
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2 retinal epithelial layers
Continuous production of aqueous humor and its active transport |
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What are the two types of ciliary muscles?
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Radial and circular smooth muscle
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What is the innervation of the ciliary muscle?
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Parasympathetic
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What occurs when the ciliary muscle contracts?
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Relaxation of zonule fibers
Lens "rounds" up |
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Collagenous fibers that attach to the capsule of the lens and assist in accomodation
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Zonule fibers
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Most anterior part of uvea, projecting from anterior edge of ciliary body
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Iris
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What does the iris separate?
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Anterior and posterior chambers
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What is the structure of the iris?
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Double layer of cuboidal epithelium
Both pigmented |
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What is the non-photosensitive extension of the receptor layer of the retina?
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Superficial/Posterior layer
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Does the anterior surface of the iris have an epithelium?
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No, loose connective tissue with incomplete layer of fibroblasts and melanocytes
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What is eye color related to?
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Abundance of pigmented cells in stroma of iris (not the epithelium)
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Large pigmented macrophage-like cells in the stroma
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Clump cells
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What are the two muscles of the iris?
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Constrictor pupillae
Dialator pupillae |
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What is the innervation of the constrictor pupillae?
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Parasympathetic
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What is the innervation of the dialator pupillae?
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Sympathetic
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What is the arrangement of the constrictor puppilae muscle?
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Smooth muscle cells in circumferential bundle
Free edge of iris |
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What is the arrangement of dilator pupillae muscle?
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Radially arrange myoepithelial cells
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What is the dialator pupillae composed of? What is its origin?
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Myoepithelial cells
From inner pigmented retina epithelium |
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What muscle is derived from the inner pigmented retina epithelium?
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Dialator puppilae
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How is the aqueous humor drained?
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Via canal of Schlemm and tracular meshwork at an angle
Drained into venous system |
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What causes glaucoma?
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Increased intraocular pressure due to draining failure of aqueous humor
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Acute angle galucoma will damage what?
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The optic nerve
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The aqueous humor provides nutrients to what?
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Avascular eye components
Cornea and Lens |
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What is the shape of the lens?
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Biconvex disc
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What is the anterior epithelium of the lens? What is the structure?
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Subcapsular epithelium
Made of simple cuboidal |
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What is the arrangement of cells in the lens anterior epithelium?
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Cells have apical surface facing inwards towards center
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What surrounds the lens?
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Capsule
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What is the capsule of the lens produced by
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Epithelium produces basal lamina
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Where do the zonule fibers insert?
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Capsule of lens
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What are lens fibers?
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Cells of lens
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From what are lens fibers derived?
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epithelial cells
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The epithelial cells that derive the lens fibers divide continuously where?
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Lens equator/germinal zone
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What protein is responsible for transparency in the lens?
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Crystallin
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What occurs as lens fibers migrate to core of lens?
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Lose cytoplasmic organelles
Accumulate crystallins |
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What is the arrangement of core fibers and cortical fibers
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Core: Parallel to optical axis
Cortical: concentrically |
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What do mature lens cells lack?
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Organelles
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Is the cytoplasm of the lens homogeneous or heterogeneous?
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Homogeneous
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What provides molecular and ionic continuity between lens cells?
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Gap junctions
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What is the shape of the cross section of lens cells?
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Hexagonal
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The cornea is responsible for ___% of light refraction
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80%
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The lens provides ____% of focusing capacity
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20%
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What is capable of accommodation?
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Lens
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When the ciliary muscle RELAXES the circular fibers and CONTRACTS the radial fibers, what happens?
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(Accommodation)
Tension increases on z. fibers Lens flattens |
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When the ciliary muscle CONTRACTS the circular fibers and RELAXES the radial fibers, what happens?
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(Accomodation)
Tension decreases on z. fibers Lens becomes more round |
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What type of vision do round and flat lenses correspond with?
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Round: Near vision
Flat: Far vision |
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What composes the vitreous humor?
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Water
Collagen fibril Hyaluronic acid Few cells |
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What cells are located in the vitreous humor?
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Hyalocytes
Fibroblasts Macrophages |
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Is the vitreous humor vascular or avascular?
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Avascular
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What is the function of the vitreous humor?
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Maintains spherical shape of globe
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What is the channel that extends through the vitreous humor from the optic disc to the posterior lens surface?
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Hyaloid canal
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How is the hyaloid canal formed?
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Residual channel resulting from the regression of the hyaloid artery during development
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What is the inner tunic?
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Retina
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Where is the nonsensory retina located?
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It is anterior, beginning at the ora serrata
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What does the nonsensory retina line?
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Ciliary body
Ciliary processes Posterior iris surface |
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Where is the sensory retina located?
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Posterior, extending from ora serrata to back of eye
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What composes the neural/sensory retina?
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Neurons
Photoreceptors Supporting cells |
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What are the 10 layers of the neural retina?
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Retina pigmented epithelium
Photoreceptor layer Outer Limiting membrane Outer nuclear layer Outer plexiform layer Inner nuclear layer Inner plexiform layer Ganglion cell layer Nerve fiber layer Inner limiting membrane |
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What are the functions of the retina pigmented epithelium?
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Protection of neural components
Nutrient provision to rods and cones Phagocytosis of outer segments Regeneration of bleach pigments |
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Where is melanin produced in the eye?
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Retina pigmented epithelium
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What does the retina pigmented epithelium share with the choriocapillaries?
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Bruch's membreane (Lamina vitrea)
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How does the retina pigmented epithelium provide nutrients to photoreceptors?
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Diffusion from the choroid capillaries
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What layer are rods and cones located in?
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Photoreceptor layer
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In what layer is light converted to nerve impulses?
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Photoreceptor layer
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Is the outer limiting membrane a true membrane?
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No
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What layer comprises the cellular junctions between photoreceptors and glial/ Muller cells?
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Outer limiting membrane
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Layer of cell bodies of rods and cones
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Outer nuclear layer
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Layer of photoreceptor axons, bipolar dendrites, and horizontal cell processes
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Outer plexiform layer
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Layer of bipolar, horizontal, amacrine, and Muller cell nuclei
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Inner nuclear layer
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Layer of bipolar cell axons, ganglion cell dendrites, and amacrine cell processes
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Inner plexiform layer
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What layer are the ganglion cell bodies located?
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Ganglion cell layer
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How do the axons of ganglion cells leave the the ganglion cell layer?
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Run parallel to surface
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The axons of ganglion cells run towards what?
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Optic disc to form optic nerve
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Where is the basement membrane and Muller cell foot processes located?
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Inner limiting membrane
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What layer does light hit first?
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Inner limiting membrane
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Where do Muller cells extend?
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From inner limiting membrane to outer limiting membrane
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What fills the space between neurons?
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Cytoplasmic processes
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Can Muller cells be seen in HE staining?
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No
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What is the purpose of Muller cells?
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Structural support for photosensitive retinal layer
Metabolic support for retinal cells |
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How many rods are in each eye?
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100 Million
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How long and wide are rods?
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40-60 um
2 um wide |
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What is the purpose of a modified cilium?
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Connects inner and outer segments of rod to cell body
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Are rods more sensitive to high or low intensity light?
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Low
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Can rods distinguish color?
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No
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Where is rhodopsin located?
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Outer segment stacks of rod
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How many cones are in each eye?
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7 million
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How long and wide are cones
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25-85 um long
2 um wide |
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What are cones responsible for?
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Visual acuity
Color |
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What is contained in the outer segment stacks of cones?
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Visual pigment Iodopsin
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Separate populations of cone respond to what colors of light?
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Red
Green Blue |
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What is the structure of the modified cilium?
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9 outer doublets, no central microtubule pair
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What organelles are contained on the inner segment of rods and cones?
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Mitochondria
ER Golgi free ribosomes |
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The outer fiber and lamella are located only in what?
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Rod
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The pedicle is located only in what?
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Cone
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What is the difference between cone and rod discs?
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Cone: discs located within PM
Rod: discs are infoldings of PM |
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What phagocytoses shed discs in the eye?
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Retinal pigmented epithelial cells
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What cell type composes the retinal pigmented epithelia?
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Simple cuboidal
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What does the basal lamina of he retinal pigmented epithelium form?
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Bruch's membrane
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What forms the blood brain barrier for retinal photoreceptors?
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Retinal pigmented epithelium
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What part of the retinal pigmented epithelium minimizes reflection by absorbing light?
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Melanin
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Where are multiple liopfuscin granules located?
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Apical cytoplasm of retinal pigmented epithelium
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What is the sensory retina divided into?
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The central retina (macula)
Larger peripheral retina |
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How large is the fovea?
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1.5 mm
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What is the rod-free area of the fovea?
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Foveola
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What cells are displaced laterally at the foveola?
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Bipolar and ganglion cells
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What is the ratio of interconnections between ganglion, bipolar, and photoreceptors?
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1:1:1
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The peripheral retina is populated mostly by what?
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Rods
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Myelination of axons begins where?
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At the optic disc (optic papilla)
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What is the function of the eyelid?
|
Distribute tear film
Eye protection |
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Do the eyelashes have an erector pili muscle?
|
No
|
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What is the eye sebaceous gland called?
|
Gland of Zeis
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What is the eye apocrine sweat gland called?
|
Gland of Moll
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What is the striated muscle of the eyelid?
|
Obicularis oris
|
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What two muscle types are present in the eyelid?
|
Obicularis oris (striated)
Smooth muscle |
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What is the fibroelastic layer of the eyelid?
|
Tarsal plate
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What are the tarsal glands called? What do they do in the eyelid?
|
Meibomian glands
Modified sebaceous gland |
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Where do the Meiobmian glands open on the eyelid?
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Inner free edge
|
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What is the muscous membrane of the eyelid called?
|
Palpebral conjunctiva
|
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What does the palpebral conjunctiva consist of?
|
Stratified columnar epithelium
Goblet cells |
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Where is the palpebral conjunctiva located?
|
Posterior surface of the eyelid
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What is a fornix?
|
Junction between eyelid and eyeball
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What does the bulbar conjunctiva merge with?
|
Stratified squamous epithelium of cornea
|
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What produces mucous for tear film?
|
Goblet cells
|
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What type of gland is the lacrimal gland (structure)
|
Compound tubulo-alveolar
|
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What type of cells curround the base of the secretory ascinus?
|
Secretory and myoepithelial cells
|
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What is the pathway of draining tear film from the eye?
|
Lacrimal puncta ----> lacrimal ducts------> lacrimal sac-----> nasolacrimal duct----->nasal cavity
|
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What are the 3 components of tear film?
|
Oily layer
Watery layer Mucous layer |
|
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What produces the oily layer of tear film?
|
Meibomian glands
|
|
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What are the functions of tear film?
|
Lubrication
Hydration Washing Refraction of light Antibiotic |
|
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What are the 6 extraocular muscles?
|
Inferior/Superior Oblique
Inferior/Superior Rectus Lateral/Medial Rectus |
|
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What maintains the shape of the eyelid?
|
Tarsus
|
|
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The lens is composed of what?
|
Proteoglycans and type IV Collage
|
|
|
Modified apocrine sweat glands that produce cerumen
|
Ceruminous glands
|
|
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What are the 3 layers of the tympanic membrane?
|
Outer (cutaneous)
Middle Inner |
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What is the middle layer of the tympanic membrane composed of?
|
2 layers of collagenous fibers
radially and circularly arranged |
|
|
What is the inner layer of the tympanic membrane composed of?
|
Thin mucous membrane, modified respiratory mucosa
|
|
|
What does the tympanic cavity communicate with?
|
Typanic antrum and air cells
|
|
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What cell types are present in the mucosa of the tympanic membrane near the Eustachian tube?
|
Squamous or cuboidal epithelium leading to columnar ciliated epithelium.
|
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What are the characteristics of the lamina propia of the tympanic membrane?
|
Thin, vascular, blends with periosteum.
|
|
|
How are the malleus, incus, and stapes connected?
|
By small connective tissue ligaments
|
|
|
What is the tendon that inserts onto the malleus and pulls it inward to increase tension on the tympanic membrane?
|
Tensor tympani
|
|
|
What tendon inserts onto the neck of the stapes, and pulls it outward to dampen movement?
|
Tensor stapedius
|
|
|
What is the epithelium transition from tympanic cavity to pharynx?
|
Simple columnar to ciliated pseudostratified columnar
|
|
|
What glands are located in the lamina propia of the auditory tube?
|
Seromucous
|
|
|
What is the relative ionic concentration of periplymph?
|
High Na, Low K
|
|
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What cells support the membranous labyrinth?
|
Stellate cells
|
|
|
What fluid and produced and contained in the membranous labyrinth?
|
Endolymph
|
|
|
What is the relative ionic concentration of endolymph?
|
Low Na, High K
|
|
|
What structures of the membranous labyrinth produce the endolymph?
|
Stria vascularis and planum semilunata
|
|
|
What bony labyrinth connets to the middle ear by the oval and circular windows and houses the utricle and saccule?
|
Vestibule
|
|
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What bony labyrinth is a spiral canal projecting anteromedially from the vestibule and contains the cochlear duct?
|
Cochlea
|
|
|
How is the cochlear duct connected to the saccule?
|
Ductus reuniens
|
|
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What is the central bony axis and lateral bony shelf of the cochlea?
|
Modiolus
Osseous sprial lamina |
|
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What is the apex of the cochlea named?
|
Helioctrema
|
|
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What is the sacal media filled with?
|
Endolymph
|
|
|
What separates the scala media from the scala vestibuli?
|
Vestibular membrane/Reissner's membrane
|
|
|
What is the thickness and composition of the vestibular membrane?
|
2 cells thick
Made of simple squamous epithelium on duct side and mesothelim on vestibular side |
|
|
What separates the the cochlear duct from the scala tympani?
|
Osseous spiral lamina
Membranous spiral lamina Basilar membrane |
|
|
What membrane supports the organ of corti?
|
Basilar membrane
|
|
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Where does the basilar membrane insert?
|
Spiral ligament
|
|
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What is the vascular stratified epithelium that produces endolymph in the cochlear duct?
|
Stria vascularis
|
|
|
What is formed by the apical projections passing up between hair cells in the Organ of Corti?
|
Apical cuticular plate
|
|
|
What forms the Tunnel of Corti?
|
Pillar cells
|
|
|
What produces the tectorial membrane?
|
Interdental cells from spiral limbus
|
|
|
What are the glycoproteins embedded in the ground substance of the tectorial membrane?
|
Otogelin
Tectorin |
|
|
What fibers enter the spiral ganlion?
|
cell bodies of bipolar neurons
Afferent fibers from Organ of Corti Efferent fibers forming cochlear nerve |
|
|
What factor causes the basilar membrane to vibrate?
|
Pitch/frequency
|
|
|
Where is the basilar membrane narrowest?
|
Near round window (highest freq)
|
|
|
Where is the basilar membrane widest?
|
Apex
(low frequency) |
|
|
What is the structure of stereocilia in the ear and it's arrangement?
|
Modified actin microvilli
Arranged in parallel rows with decreasing height |
|
|
What is the structure and location of the kinocilium?
|
Microtubule containing cilium
Behind tallest stereocilia (Cupula) |
|
|
What connects the utricle to saccule?
|
Ductus utriculo-saccularis
|
|
|
What connects the saccule to the cochlear duct?
|
Ductus reuniens
|
|
|
What does the macula contain?
|
Supporting cells
Sensory hair cells |
|
|
What produces endolymph in the macula?
|
Planum semilunatum
|
|
|
Capillaries contain only what tunic?
|
Tunica intimia
|
|
|
Where are cell junctions strongest and loosest?
|
Strongest: arterioles
Loosest: venules |
|
|
What does the permeability barrier consist of?
|
Basement membrane and endothelium
|
|
|
What charges do the basement membrane and endothelium carry?
|
Basement: +
Endothelium: - |
|
|
What vessels do not have vascular smooth muscle?
|
Capillaries
Some venules |
|
|
What is unique to elastic arteries?
|
Concentric lamellae: interlaced, fenestrated sheets of elastic fibers
|
|
|
What imparts tensile strength in vasculature?
|
Collagen
|
|
|
Is the tunica intima and inner tunica media fed by the vasa vasorum?
|
No; receive nutrients via diffusion from lumen
|
|
|
Nerves supply all vasculature except what?
|
Capillaries
|
|
|
Where are chemo and baroreceptors located in the vasculature?
|
Tunica adventitia
|
|
|
What is the characteristic of the internal and external elastic lamina of the elastic artery?
|
They're not distinct
|
|
|
What is prominent in the muscular/distributing arteries?
|
Internal elastic lamina
|
|
|
Which vessels are most prone to disease?
|
Muscular/distributing arteries
|
|
|
What structure maintains blood pressure?
|
Metarterioles (precapillary sphincters)
|
|
|
What causes anaphylactic shock?
|
Arteriole muscle paralysis
|
|
|
What are capillaries composed of?
|
Endothelium and basement membrane
|
|
|
What is the most common type of capillary and what is its structure?
|
Continuous capillary
Continuous endothelium and basement membrane |
|
|
What is the structure of fenestrated capillaries?
|
Attenuated endothelium
Continuous basement membrane |
|
|
Where are fenestrated capillaries found?
|
Tissues with rapid interchange of gases and metabolites
|
|
|
What capillary has the largest diameter? What is its structure?
|
Discontinuous capillaries
Discontinuous basement membrane |
|
|
What capillary has the slowest flow of blood?
|
Discontinuous capillaries
|
|
|
Where are discontinuous capillaries located?
|
Spleen and liver
|
|
|
What is characteristic of post-capillary venules?
|
Pericytes
Vessel involved with cell movement into or out of space |
|
|
What is characteristic of muscular venules?
|
Thick tunica adventitia
Associated with arterioles Extensive tight and gap jxns |
|
|
What forms semilunar valves in medium veins?
|
Tunica intima
|
|
|
What are the semilunar valves?
|
Tricuspid valves
Aortic and pulmonary trunks |
|
|
What are the atrio-ventricular valves?
|
Atrial and ventricular valves connected by chordae tendinae
|
|
|
What forms the cardiac skeleton?
|
Dense irregular CT
|
|
|
What are three parts of the cardiac skeleton?
|
Annuli fibrosi
Fibrous trigones Septum membranaceum |
|
|
What does rheumatic fever affect?
|
Cardiac skeleton
|
|
|
What forms the superior portion of the interventricular septum?
|
Septum membranaceum
|
|
|
Where is the myocardium proper thickest and thinnest?
|
Thickest: ventricle
Thinnest: atria |
|
|
Can myocardial tissue regenerate?
|
No
|
|
|
What is humoral immunity?
|
Antibodies against antigens
Plasma cell produced (B lymphocyte derive) |
|
|
What is cellular immunity?
|
Cells contact and react against (destroy) antigen
T lymphocyte |
|
|
What are the primary lymphoid organs?
|
Bone marrow
Thymus |
|
|
What is responsible for setting up cellular immunity?
|
Thymus
|
|
|
What is responsible for setting up humoral immunity?
|
Bone marrow
|
|
|
What produces antibodies?
|
Plasma cells
|
|
|
What are 3 secondary lymphoid organs and their responsibilities?
|
Spleen
Lymph Nodes Lymphatic nodules Filter out and react to antigens |
|
|
What three fluids do secondary lymphoid organs act on?
|
Tissue fluid
Lymph Blood |
|
|
What structure filters tissue fluid and are located underneath the epithelial lining of organs leading to the outside of the body?
|
Lymphatic nodules
|
|
|
What structure filters lymph?
|
Lymph nodes
|
|
|
What structure filters blood?
|
Spleen
|
|
|
What percentage of circulating lymphocytes are B? T?
|
B: 35%
T: 65% |
|
|
What is the route of B lymphocytes?
|
Travel to secondary lymphoid organs to proliferate to form colonies and differentiate into anti-body secreting cells
|
|
|
Where do T lymphocytes originate and then migrate?
|
Originate in bone marrow, proliferate in thymus
|
|
|
What do helper T cells do?
|
Stimulate B----> plasma cells
|
|
|
What type of cell is killed by AIDS?
|
Helper T cells
|
|
|
What do killer T cells do?
|
Kill foreign cells directly by cell lysing
|
|
|
What to T memory cells do?
|
Stimulate production of killer cells when antigen reintroduced
|
|
|
What are immunoblasts?
|
Basophilic cells from T/B cells that occur when exposed to antigen.
|
|
|
What traps antigens, then process them and present them to lymphocytes
|
Antigen-presenting cells
|
|
|
From what are antigen-presenting cells derived? What cell system do they belong to?
|
Derived from bone marrow
Differentiations belong to monocyte-phagocyte system |
|
|
How are antigens processed by antigen presenting cells?
|
Phagocytosed foreign mateial
Partial digestion in lysosomes Return of breakdown prouct to cell surface-------> stimulate lymphocyte |
|
|
What is the origin of reticular cells? What is their function?
|
From Mesoderm
make reticular fibers; act like fixed macrophages |
|
|
What is unique about reticular fibers of the thymus?
|
Endodermal origin
Do not form reticular fibers |
|
|
What is the importance of reticular fibers in the lymphatic system?
|
Filter/Trap antigens and immunocompetent cells
Line lymphatic capillaries Support lymphoid elements |
|
|
What is MALT
|
Mucosa Associated Lymphoid Tissue
|
|
|
What are some examples of MALT tissues?
|
Gastrointestinal tract
Tracheobronchial tree Genitourinary tract |
|
|
Where are MALT tissues located?
|
Lamina propia
|
|
|
What do MALT tissues not have?
|
Afferent lymphatic vessels
|
|
|
What section of the lymphatic nodule is B dependent?
|
Germinal center
|
|
|
What is the structure/arrangement of a lymphatic nodule?
|
Germinal center: pale staining; composed of dividing cells
Outside: tightly packed small lymphocytes |
|
|
Are solitary nodules encapsulated by dense connective tissue?
|
No
|
|
|
What is HEV associated with? What is HEV?
|
HEV is high endothelial venules
Associated with solitary nodules and MALT |
|
|
What are large aggregations of lymphoid in the lamina propia (abmesenteric side) of the small intesting?
|
Peyer's patches of ileum
|
|
|
What is unique about the appendix?
|
Small lumen and very active large lymphoid nodules
|
|
|
Where are tonsils found? What do they form?
|
Found in fauces
Form ring of Waldeyer |
|
|
What do the tonsils consist of?
|
2 palatine
2 lingual 1 Pharyngeal |
|
|
What is produced in the tonsils?
|
Lymphocytes
|
|
|
Where are the palatine tonsils located?
|
glossopalatine and glossopharyngeal arches
|
|
|
What covers the palatine tonsils to form crypts?
|
Stratified squamous epithelium
|
|
|
Where is the pharyngeal tonsil located?
|
(Unpaired) on roof and posterior wall of nasopharynx
|
|
|
What lymphatic structure is lined with respiratory epithelium?
|
Pharyngeal tonsil
(Psuedostratified ciliated columnar) |
|
|
Does the pharyngeal tonsil have crypts?
|
No (folds)
|
|
|
What tissues form the pharyngeal tonsil?
|
Diffuse and nodular tissue
|
|
|
What lines lingual tonsils?
|
Moist stratified squamous epithelium
|
|
|
Where are lymphatic channels NOT found?
|
Eye, internal ear, epidermis, cartilage, bone, bone marrow, CNS
|
|
|
What causes lymph flow?
|
Breathing and contraction of skeletal muscle
|
|
|
What is contained in the lymph?
|
Water, electrolytes, plasma proteins, antibodies
|
|
|
Do lymphatic capillaries have a continuous basement membrane?
|
No
|
|
|
Do lymphatic vessels have valves?
|
Yes, some
|
|
|
What forms the stroma of the lymph nodes?
|
Reticular cells and fibers
|
|
|
Is the lymph node surrounded by connective tissue layer?
|
Yes
|
|
|
Describe the flow of lymph through the lymph node sinuses, starting afferently.
|
Afferent lymph vessels----->marginal/subcapsular sinus----->cortical sinus----->medullary sinus-----> efferent lymph channel
|
|
|
What zones are found in the far and deep cortical areas of the lymph node?
|
Far: B cell dependent
Deep: T cell dependent |
|
|
What is formed in the lymph nodes by a couple of layers of small lymphocytes surrounding blood capillaries?
|
Medullary cords
|
|
|
How much of the antigen is removed by the macrophages of the lymph node?
|
99%
|
|
|
How do long lived lymphocytes re-enter lymph node?
|
Via HEV
High Endothelial Venules |
|
|
What is the largest lymphoid organ?
|
Spleen
|
|
|
What gives rise to trabeculae in the spleen?
|
Thin capsule that surrounds whole organ
|
|
|
What is the PALS (periarterial lymphoid sheath)
|
Lymph tissue surrounding a central artery where trabeculae leave spleen
T-cell dependent |
|
|
What is the red pulp of the spleen?
|
Network of venous sinuses and cords
|
|
|
What portion of the spleen receives the major portion of incoming arterial blood?
|
Marginal zone
|
|
|
What are penicillar arteries?
|
Arterioles that pass into red pulp
|
|
|
Do veins of red pulp have continous basal lamina?
|
Yes
|
|
|
Where does the splenic vein drain from?
|
Hilus
|
|
|
What is the open circulation theory of the spleen?
|
Capillaries open directly into red pulp and gradually filter into sinuses
|
|
|
What evidence supports the open theory?
|
RBC in cords
Dye in splenic artery: goes into cords and then sinuses Dye into splenic vein: sinuses and cords fill easily, not arteries |
|
|
What is the closed circulation theory of the spleen?
|
Capillaries communicate directly with lumens of venous sinuses
|
|
|
What evidence supports the closed theory of circulation?
|
Not enough RBCs in cords
Dye experiments may rupture vessels |
|
|
Where are RBCs, platelets, and leukocytes destroyed in the spleen?
|
Pulp cords
|
|
|
How is hemoglobin degraded in the spleen?
|
Cord macrophages metabolize iron and store it as hemosiderin pigment
|
|
|
What is degraded hemoglobin stored as?
|
Hemosiderin pigment
|
|
|
How is heme degraded in the spleen?
|
Degraded to bilirubin and excreted in bile
|
|
|
Where are RBCs produced in the fetus?
|
Spleen
|
|
|
What's produced in the spleen throughout life?
|
Lymphocytes and macrophages
|
|
|
Does the thymus have nodules?
|
No
|
|
|
What influences the involution of the thymus?
|
Age
Adrenal cortical steroids Radiation |
|
|
What are thymocytes?
|
Thymus lymphocytes
|
|
|
What assists the development of thymocytes?
|
Hemopoietic stem cells
|
|
|
Are thymocytes self-renewing?
|
No
|
|
|
What is characteristic of the cortex of the thymus?
|
Stellate stroma
Tonofibril bundles Euchromatic oval nuclei |
|
|
Only 5% of thymus thymocytes reside where?
|
Medulla
|
|
|
What thymus structures are filled with keratohyalin granules that degenerate cells?
|
Hassall's corpuscles
|
|
|
What happens to lymphocytes that proliferate in the thymus cortex?
|
Migrate to medulla, then secondary lymphoid organs to divide and mature in T dependent areas
|
|
|
What is the structure and arrangement of the epidermis?
|
Keratinized stratified squamous epithleium
|
|
|
What are the 5 skin layers (Superficial to Deep)
|
Stratum Corneum
Stratum Lucidum Stratum Granulosum Stratum Spinosum Stratum Basale |
|
|
What attaches the stratum basale to the basement membrane?
|
Hemidesmosomes
|
|
|
Desmosomes form what in the stratum spinosum?
|
Intercellular bridges
|
|
|
Where are Langerhans cells present? Merkel cells?
|
Merkel: Stratum basale
Langerhans: Spinosum |
|
|
What layers are affected by psoriasis?
|
Basale and Spinosum
|
|
|
What is accumulated in the statum granulosum when they become flattened?
|
Keratohyalin granules and intermediate keratin filaments
|
|
|
What is keratohyalin composed of?
|
Histidine and cystine rich proteins
|
|
|
What is the most superficial layer where nuclei are present?
|
Stratum granulosum
|
|
|
What do stratum lucidum cells contain that is unique?
|
Eleidin, which is transformed from keratohyaline
|
|
|
What is darkened skin color (tanning) due to?
|
Increased melanin production
Darkening of existing melanin |
|
|
What is the function of Langerhan's cells? Where do they originate?
|
Function: antigen-presenting clels
From: bone marrow |
|
|
In what layer are Langerhan's cells most prevalent?
|
Spinosum
|
|
|
An increase in chronic inflammatory diseases of the skin will increase what cell?
|
Langerhan's cell
|
|
|
Merkel's cells are found in thick/thin skin
|
Mostly thick skin
|
|
|
What does thick skin lack?
|
Hair follicles
Sebaceous glands Erector pili muscles |
|
|
What does thin skin lack?
|
Straum lucidum and granulosum
|
|
|
What collagen type is found in the dermis?
|
Type I
|
|
|
What detects pressure?
|
Pacinian corpuscles
|
|
|
What detects touch, and is only found in dermal papillae?
|
Meissner's corpuscles
|
|
|
A blister is a fluid accumulation where?
|
Dermo-epidermal junction
|
|
|
Epdiermolysis bullosa will cause what?
|
Blisters (due to weak junctions)
|
|
|
What is the structure of eccrine glands?
|
simple coiled tubular
|
|
|
What innervates apocrine sweat glands?
|
Adrenergic fibers
|
|
|
Where are sebaceous glands absent?
|
Palms and soles
|
|
|
What secretions does sebaceous glands produce?
|
Oily sebum
|
|
|
What overlies the lunula in the nail?
|
Cuticle (eponychium)
|
