Module 4 Lab

three layers of the eye

outer- fibrous tunic

vascular tunic

inner - inner tunic

fibrous tunic consists of

cornea and sclera

cornea

transparent

dense regular connective tissue

layer of epithelial tissue on both the outer and inner surfaces

light enters the eye

forms part of the light-bending apparatus

sclera

wraps the back of the eye

dense irregular connective tissue

protects the eye and contributes to its space

white of the eye

anchoring site for the extrinsic eye muscles

vascular tunic

choroid, ciliary body, iris, and pupil

choroid

rich with blood vessels and melanin

absorbs light as it enters the back of the eye to prevent scattering

ciliary body includes and controls

ciliary muscles and ciliary processes

controls the lens

ciliary muscles

smooth muscle

focuses the lens

ciliary processes

extends from the entire circumferences of the lens

ciliary zonule

where the ciliary processes attach to the lens

iris

colored portion of the eye

has two layers of smooth muscle which constrict and dilate the pupil

bright light and close vision - constrict pupil

low light and far vision - contracts - widens the pupil

pupil

allows light to come in

inner tunic contains

retina and optic nerve

pigemented layer to prevent light from scattering

retina

where the photoreceptors (cones and rods) are located

optic nerve

nerve from the eye to the brain

fovea centralis

composed entirely of cones

area of the retina with the highest visual acuity

rod cells

more sensitive to light and permit vision in dim light

cone cells

operate best in bright light and enable high-acuity color vision

optic disc

where the optic nerve exits the eye

a blind spot is created on that region of the retina because there are no photoreceptors

lens

biconvex disc composed mostly of protein that changes shape to allow the eye to focus on objects from different distances

ciliary zonule

lens is held in place by this

series of ligaments that connect the lens to the ciliary processes

anterior segment

in front of the lens

contain aqueous humor (water like )

posterior segment

behind the lens

contains vitreous (gel like) humor

vitreous humor

transmits light, supports posterior surface of the lens, and maintains intraocular pressure (normal pressure within the eye)

what do the ciliary processes make

aqueous humor - which is circulates throughout life

where does the aqueous humor drain to

the scleral venous sinus (canal of schlemm) into venous blood

vitrous humor life

just produced once prior to birth

accomodation

ciliary zonule

focus on distant objects- ciliary muscle is relaxed, ciliary zonule is tighlty pulled on sides of the lens

lateral rectus muscle

moves the eye laterally

medial rectus

moves the eye medially

superior rectus

moves the eye superiorly and medially

inferior rectus

moves the eye inferiorly and medially

inferior oblique

originates in the medial orbit

loops under the eye

inserts on the lateral sclera

moves the eye superiorly and laterally

superior oblique

originates on the back of the eye near the rectus muscle

runs medially toward orbit

loops through the trochlea ligament

inserts on the superior sclera

moves the eye inferiorly and laterally

regions of the ear

external, middle, and internal

external ear

captures the sound waves

auricle, external acoustic meatus

middle ear

conducts the sounds waves to the deeper structures of the ear

pharyngotympanic tube, ossicles, and cochlea

auricle

captures and conducts the sound waves toward the external acoustic meatus

tympanic membrane

sound waves vibrate against here

ear drum

auditory ossicles

3 tiny bones, sound is conducted to here

pharyngotympanic tube

eustachian tube

allows for pressure equalization between the middle ear and the pharynx

cochlea

organ of the internal ear that is responsible for hearing

vestibule and semicircular canals

responsible for sensing balance and equilibrium

malleus

first of the three middle ear ossicles

when the tympanic membrane vibrates, the malleus rocks

incus

conducts the sound waves to third ossicle

second ossicle

stapes

third ossicle

pushes the waves of sound up against the oval window

oval window

seperates the middle ear from the vestibule of the interal ear

hair cells

located inside the cochlea, bathed in endolymph

located in the cochlea - responsible for detecting sound

how does sound work with hair cells

sound waves reach the cochlea, the fluid moves, thereby moving and ultimately exciting the hair cells

vestibule

contains the utricle and saccule

senses linear movements like tilting the head forward

semicircular canals

posterior to the vestibule

sense rotational movement - spinning around in a chair

how many chambers in the cochlea

3

top - scala vestibuli

middle - scala media

bottom - scala tympani

which chambers have perilymph

scala vestibuli and scala tympani

perilymph

very similar to the cerebrospinal fluid

scala media

where the receptors for hearing are located

vestibular membrane

scala vestibule and scala media separated

basilar membrane

separates the scala tympani and scala media

acellular

endolymph

fluid that is high in potassium ions

organ of corti

sensory epithelium for hearing

hair cells in the cochlea cross section

three rows of outer hair cells

single row of inner hair cells amongst columnar supporting cells

stereocilia

mechanoreceptors of the hair cells have finger like projections on their apical surface

not cilia or microbilli

tectorial membrane

gelatinous, acellular membrane

on top of the stereocilia

is stationary

plasma

all connectisue tissue composed of the matrix which is called the plasma

cells in blood

formed elements

erthrocytes

red blood cells

responsible for oxygen transport

thrombocytes

platelets

are involved in hemostasis - blood clotting

leukocytes

white blood cells

responsible for fighting disease

most diverse of the formed element

wright stain

purple stain adheres to parts of the WBCs, which make them visible under the microscope

granulocytes

grainy looking cytoplasm, because the stain adheres to their vesicles

eosinophils, basophils, and neutrophils

eosinophils

stain red

responsible for fighting parasitic infections and are rare

basophils

stain blue

responsible for the inflammatory response

neutrophils

light purple color

responsible for phagocytosis of foreign bodies

agranulocytes

lymphocytes and monocytes

lymphocytes

responsible for immunity (fighting and remembering diseases)

monocytes

largest

work with neutrophils as phagocytes

Mnemonic of WBC abundance

Never let monkeys eat bananas

chambers of the heart

right atrium, left atrium, right ventricle, left ventricle

where is the apex

pointing downward and leftward

superior vena cava and inferior vena cava

bring deoxygenated blood to the right atrium

pulmonary trunk

takes deoxygenated blood from the right ventricle to the lungs

branches into left and right pulmonary arteries

pulmonary veins

carry oxygenated blood to the left atrium

ascending aorta

carries oxygenated blood from the left ventricle to all of the body’s systems

turns left and posterior to become the aortic arch

ligamentum arteriosum

ligament that connects the pulmonary trunk to the aorta

before birth it is called the ductus arteriosus

ductus arteriosus

detours blood from the pulmonary trunk to the aorta, bypassing the lungs, because the fetus is not yet breathing

interatrial septum

tissue that seperates the right and left atria

fossa ovalis

oval shaped depression

remnant from the fetus

foramen ovale

before birth the hole was named this

allows blood to move from the right atrium to the right ventricle, the right atrioventricular

tricuspid valve

prevents the backflow of blood from the right ventricle to the right atrium

chordae tendinae

prevents the valves from inverting and failing

connect the underside of the valve to papillary muscles

pulmonary semilunar valve

prevents the backflorw of blood from the artery back to the right ventricle

does not have chordae tendinea

interventricular septum

ensures that deoxygenated blood on the right side of the heart remains separate from oxygenated on the left

mitral valve / left atrioventricular valve

prevents backflow of blood from the ventricle to the atrium

why is the wall of the left ventricle so much thicker than the right

it pumps oxygenated blood to the entire body

blood vessels

blood is circulated throughout the body by blood vessels

arteries

vessels that carry blood away from the heart, branch into smaller arterioles

arterioles

feed into capillaries

capillaries

exchange vessels

feed into venules

venules

combine to form veins

veins

the vessels that return blood to the heart

artery and veins layers of tissue

tunica intima - innermost

tunica media - middle layer

tunica externa - outer layer