A and P II Lab exam 1

labs 1-4, special senses to blood vessels

Accessory structures of the eye

eyelids

eyelashes

eyebrows

lacrimal apparatus:

lacrimal sac, lacrimal canaliculus, nasolacrimal duct, lacrimal gland.

extrinsic eye muscles

cornea

admits and refracts (bends) light

sclera

provides shape and protects inner parts

lens

refracts light

choroid

provides blood and absorbs scattered light

ciliary body

secretes aqueous humor an dalters shape of lens for near or far vision (accommodates)

Iris

colored portion of the eyeball

controls the size of the pupil! based on autonomic reflexes (occurs involuntarily)

pupil constriction vs dilation

parasympathetic | sympathetic

miosis: excessive shrinking of the pupil | mydriases

muscle involved: sphincter pupillae | dilator pupillae

Light hits retina, the signal travels via the optic nerve to the pretectal nucleus in the midbrain.

Chambers of the eye

anterior chamber and posterior chamber, which are separated by the iris.

Anterior chamber of the eye

b/n the iris and cornea

filled with aqueous humor (a clear, watery liquid)

Posterior chamber of the eye

lies behind the iris and in front of the lens and is also filled with aqueous humor

behind this, is the posterior cavity (vitreous chamber) filled w (vitreous humor) a transparent, gelatinous substance.

Retina

begins with the ora serrata and continues posteriorly, lining the interior of the choroid.

lines the posterior three-quarters of the inner layer of the eyeball.

the exact center of the middle (neural layer) macula lutea,

contains a pigmented and neural layer (contains photoreceptors and associated receptors, rods and cones)

*the point at which the optic nerve exits the eye is the optic disc.

optic (II) nerve is visible

Macula lutea

middle of retina

contains fovea centralis (central fovea), an area of the highest density of cones of any area of the retina (area of highest visual acuity)

the light rays refelcted from an object are focused onto the central fovea.

Rod

used in night vision, to see dim light

responds to low levels of light

allows us to perceive shades of gray, black, and white

cones

produce color vision and provide high visual acuity.

requires brighter light for stim.

rods and cones

from these censors, info forms through the outer synaptic layer to bipolar cells through the inner synaptic layer to ganglion cells

• axons of these exit as the optic (II) nerve

extrinsic eye muscles

6 skeletal muscles that insert on the exterior of the eyeball to move the eyeball in all directions

superior, inferior media and lateral rectus muscles

the superior and inferior oblique muscles

superior rectus

extrinsic eye muscle

moves the eyeball superiorly

lateral rectus

extrinsic eye muscle

moves the eyeball laterally

medial rectus

extrinsic eye muscle

moves the eyeball medially

superior oblique

extrinsic eye muscle

moves the eyeball laterally and inferiorly

inferior oblique

extrinsic eye muscle

moves the eyeball laterally and superiorly

lacrimal apparatus

produces and drains tears

flow of tears

lacrimal gland: secretes tears into

excretory lacrimal ducts: distributes tears over surface of eyeball

superior or inferior lacrimal canaliculi drains tears into

Lacrimal Sac, which drains tears into

nasolacrimal duct, which drains tears into

nasal vacity.

color blindness

red-green most common form

auricle (pinna)

part of external ear

collects sound waves

*rim is called helix, fleshy inferior is the lobule (lobe)

external auditory canal (external auditory meatus)

part of external ear

directs sound waves to eardrums

tympanic membrane (eardrum)

part of external ear

reacts to sound waves with vibration, which in turn causes the malleus to vibrate. middle man for malleus?

auditory ossicles

part of middle ear

transmit and amplify vibrations from tympanic membrane to oval window.

auditory tube (eustachian tube)

part of the middle ear

equalizes air pressure on both sides of tympanic membrane

cochlea

part of the internal (inner) ear

contains a series of fluids, channels, and membranes that transmit vibrations to spiral organ (organ of corti), the organ of hearing; hair cells in spiral organ produce receptor potentials, which elicit nerve impulses in cochlear branch of vestibulocochlear (VIII) nerve.

Vestibular apparatus

part of the internal (inner) ear

includes semicircular ducts, utricle, and saccule, which generate nerve impulses that propagate along vestibular branch of vestibulocochlear (VIII) nerve.

semicircular ducts

part of the internal (inner) ear

detect rotational acceleration or deceleration

utricle

part of the internal (inner) ear

detects linear acceleration or deceleration that occurs in a horizontal direction and also head tilt.

Saccule

part of the internal (inner) ear

detects linear acceleration or deceleration that occurs in a vertical direction.

steps to hearing sound

6 steps

1.) sound waves are collected by the auricle and travel to external auditory meatus and then the tympanic membrane (eardrum)

2.) movement of the tympanic membrane causes displacement of the auditory ossicles (malleus, incus, then stapes).

3.) movement of the stapes at the oval window establishes pressure waves in the perilymph of the scala vestibuli

4.) the pressure waves distort the basilar membrane on their way to the round window of the scala tympani

5.) vibration of the basilar membrane causes hair cells (in the organ of Corti) to vibrate against the tectorial membrane

6.) info about the region and the intensity of stim. is relayed to the CNS over the cochlear branch of cranial nerve VIII.

Spiral organ (organ of Corti)

dynamic equilibrium

maintenance of the body’s position in response to sudden movements.

static equilibrium

maintenance of the body’s position relative to the force of gravity.

Equilibrium organs of the inner ear/function

Saccule, utricle (both otolithic organs), and semicircular canals.

Intrinsic (wall) layer of the eyeball

3 layers

1.) fibrous tunic

• cornea and sclera

2.) middle vascular tunic

• iris, ciliary body, and choroid.

3.) inner tunic (retina)

• pigmented and neural layer

• macula lutea, fovea centralis (sharpest vision) , optic disc

optic disc

located in the retina (inner tunic)

a blind spot

3 Principal layers of the retina (neural layer)

1.) Ganglion Cell Layer (most superficial): its axons form the optic nerve

2.) Bipolar Cell Layer (middle): relays signal

3.) photorecepter layer (deepest), made of cones (bright light, color, detail) and rods (dim light, black and white)

function of tears

lacrim = tears

lubricates and cleanses the eye, and supplies oxygen and nutrients to the cornea. Also contaisn lysozyme and antibodies for antimicrobial protection.

visual acuity tests

measure the ability of the lens to focus light reflected from an object on the central fovea of the retina.

snellen eye chart for distance visual acuity

snellen acuity card for near visual acuity.

ishihara color blindness test for color blindness

pituitary gland

connected to the hypothalamus by the infundibulum

anterior pituitary gland

produces GH, TSH, ACTH, FSH, PRL, PRL

*refer to endocrine system quiz flashcards for more in depth info

posterior pituitary

neural tissue, stores and releases hormones made in the hypothalamus, doesn’t make any

releases:

ADH

oxytocin

pineal gland

located in the epithalamus of the brain

produces melatonin

thyroid gland

anterior to the trachea, with two lobes connected by the isthmus

T4 (thyroxine)

T3 (triiodothyronine)

calcitonin

parathyroid glands

four small glands on the posterior surface of the thyroid

PTH (parathyroid hormone)

adrenal glands

sit atop each kidney, have an outer cortex and inner meduola

contains adrenal cortex and adrenal medulla

adrenal cortex

located in adrenal glands

Zona glomerulosa → aldosterone

Zona Fasciculata → cortisol

Zona Reticularis → androgens

Adrenal Medulla

located in adrenal glands

Epinephrine

Norepinephrine

Pancreas

*exocrine and endocrine gland

alpha cells→ glucagon, raises blood glucose

beta cells → Insulin, lowers blood sugar

delta cells → somatostatin, inhibits both insulin and glucagon release

testes

testosterone, produced by leydig cells

ovaries

estrogen

progesterone

zona glomerulosa

outermost layer of the adrenal cortex, cells arranged in tight, ball-like clusters

secretes mineral (corticoids, mainly aldosterone)

Zona fasciculata

second most outer layer of the adrenal cortex

cells arranged in long, straight cords ( a fascicle like look)

secretes glucocorticoids, mainly cortisol

zona reticularis

third outermost layer of the adrenal cortex

secretes androgens

adrenal medulla

innermost region of the adrenal cortex

chromaffin cells secrete epinephrine and norepinephrine

pancreatic islets

hypothalamus and pituitary gland relationship

work together to control other endocrine glands

hypothalamus tells pituitary gland what to do and the pituitary gland tells the others.

Blood function

transports oxygen, nutrients, and hormones to body tissues

transports carbon dioxide, heat, and metabolic wastes away from body tissues.

formed elements

RBC’s, WBC’s, platelets (AKA thrombocytes, cell fragments)

makes up 45% of blood volume

plasma

carries blood cells, etc.

clear, straw colored liquid

55% of blood volume

consists of 91.5% water, 8.5% solutes.

solutes are mostly plasma proteins, but also nutrients, blood gases, and electrolytes, hormones, enzymes, and waste materials,

buffy coat

a thin, pale middle layer of white blood cells and platelets that forms when a blood sample is spun in a centrifuge

makes up less than 1% of blood volume

erythrocyte

red blood cell

small, anucleate (w/o a nucleus) bioconcave cells that contain hemoglobin

size: 7-8 µm diameter\

no granules or nucleus

color of cytoplasm: light pinkish red

Hemoglobin

a large molecule used to transport oxygen and carbon dioxide in the blood

contains a red pigment called heme.

Platelets

thrombocytes

cell fragments

formed in red bone marrow from large, multinuclear cells called megakaryocytes that break into tiny cytoplasmic fragments

ptoects the body by forming a platelet plug to stop bleeding when blood vessels rupture and aiding in blood clotting by secreting chemicals

2-4 µm in diameter, no nucleus, dark purple granules, tough to see cytoplasm

leukocytes

white blood cells

nucleated cells, larger than RBC’s

attack pathogens and other foreign substances in the body

5 kinds of leukocytes divided into 2 types: granular and agranular

Granulocytes (granular leukocytes)

has discernible granules in the cytoplasm that can be seen after staining

3 types:

neutrophils

eosinophils

basophils

angranulocytes (agranular leukocytes)

also has granules, but not visible by light microscope

2 types: lymphocytes and monocytes

polycythemia

abnormally high number of RBC’s

approx. 4.8-5.4 million RBC’s per microliter of blood

anemia

an unusually low number of RBC’s

approx. 4.8-5.4 million RBC’s per microliter of blood

agglutination

essentially “clump”

in blood, the clumping together of RBC’s when specific antibodies bind to the surface of antigens.

Hematocrit

the percentage of blood volume occupied by RBC’s

to determine it, a capillary tube of blood is centrifuged to pack the red cells at the outer end of the tube, separating them from the WBC’s, platelets and plasma.

normal hematocrit range:

female: 38-46 percent

male: 40-54 percent

neutrophils

~ 60%

Lymphocytes

~30%

Monocytes

~6%

eosinophils

~3%

basophils

~1%

Microanatomy of blood vessel walls

contains 3 layers, or tunics

Tunica Intima (innermost layer)

Tunica Media

Tunica Externa (outermost layer

Tunica intima

innermost layer of blood vessel walls, think of how someones deepest layer is the most intimate

Tissues: endothelium (simple squamous), basement membrane, and elastic tissue

Function: minimizes friction

tunica Media

middle layer of the blood vessel wall

tissues: smooth muscle fibers and elastic fibers *middle layer would require more elasticity

Function: controls vessel diameter through vasoconstriction and vasodilation, regulated by the sympathetic nervous system

*thickest layer

Tunica externa

outermost layer of the blood vessel walls

tisues: elastic and collagen fibers externa like external skin, collagen level is evident in the appearence of our skin

Function: provides support and protection

Blood vessel structures of arteries/ how it’s diff from veins and capillaries

has the normal 3 tunica layer (intima, media, and externa)

thickness and exact comp depends on the vessel type

Elastic arteries: more elastic fibers in the tunica media, ex.) aorta

Muscular arteries: smaller in diameter than elastic, branches into smaller arteries called arterioles. *arterioles have a tunica media w/ mainly smooth muscle and few elastic fibers

Blood vessel structures of Veins/ how it’s diff from arteries and capillaries

Tunica externa is the thickest layer of this blood vessel

*external/internal elastic lamina is absent.

all three layers are thinner in this blood vessel than arteries, but lumen is larger

Blood vessel structures of capillaries / how it’s diff from arteries and veins

tunica layers of this blood vessel have the smallest diameter and thinnest walls

lumen is very small

the walls are comprised of a single layer of endothelial cells

the endothelial cells of this blood vessel exhibit:

tight junctions, intercellular clefts, vesicles, fenestrations.

apical pulse

measured with a stethoscope placed directly over the apex of the heart

gives direct measure of actual heart rate

radial pulse

measured by palpating the radial artery at the wrist, on the thumb side, This is a peripheral pulse.

korotkoff sounds

sounds when taking bp

relation of systolic and diastolic pressures to the events of the cardiac cycle

systoplic pressure corresponds to ventricular systole: the peak pressure in the arteries as the ventricle contract and eject blood

diastolic pressure: ventricular diastole- the lowest arterial pressure, occuring while the ventricles are relaxed and refilling *makes sense as blood flow becomes normal again and we can’t hear the korotkoff sounds anymore

systemic circ

Direction: Left ventricle → aorta → systemic arteries → arterioles → systemic capillaries (all body tissues except the pulmonary alveoli) → venules → systemic veins → right atrium

right side of the heart

Circuit that carries deoxygenated blood returning from the systemic circulation between the heart and lungs for the purpose of gas exchange.

Oxygen Transport:

Blood entering the heart is deoxygenated

Blood leaving the heart is oxygenated

pulmonary circ

right ventricle → pulmonary trunk → pulmonary arteries → pulmonary capillaries (around alveoli, in both lungs) → pulmonary veins → left atrium

right side of the heart

Circuit that carries deoxygenated blood returning from the systemic circulation between the heart and lungs for the purpose of gas exchange.

Oxygen Transport:

Blood entering the heart is deoxygenated

Blood leaving the heart is oxygenated

fetal circ

cant breathe or ingest food, so the mother’s circ system provides with oxygen and nutrients, and expels waste.

Exchnage occurs across placenta

2 umbillical arteries carry oxygen-poor fetal blood to the placenta where nutrients is added.

umbilical vein travels to the liver

ductus venosus

foramen ovale

ductus arteriosus

hepatic portal system

involves the blood from the digestive organs, and starts in liver

blood from digestive organs drain through this portal vein, which delivers it tio the liver

In liver, blood passes through

circle of willis

ring of connected arteries at base of brain

formed by anterior and posterior arteries

provides collateral circulation- if one artery becomes blocked, blood can still reach all regions of the brain via alternate routes because of circular shape