eye notes

sclera

support, protection and movement

cornea

main refractive (light-bending structure)

choroid

blood supply and light absorption

ciliary body and muscles

after shape of lens for focusing

iris and pupil

regulation of amount of light entering eye

pigmented layer

absorb light, vitamin A storage

neural layer

photoreception and vision

macula lutea, fovea

area of maximal visual acuity

optic disc

site where optic nerve exits

conjuctiva

lubrication and protection of eyeball

lens

refractive structure: focusing

suspensory ligaments

connect lens to ciliary body

aqueous humor in anterior segment

nourishment and ocular pressure

vitreous humor in posterior segment

support of retina and ocular pressure

photoreceptors

rods and cones

rods

non color vision

rods

high sensitivity; function in dim light

rods

low acuity

rods

more numerous

rods

mostly in peripheral retina

rods

visual pigment : Rhodopsin

cones

colour vision

cones

low sensitivity ; function in bright light

cones

high acuity

cones

less numerous

cones

mostly in central retina

cones

visual pigment : photospins ( blue, green, red)

image fornation

refraction of light

accomodation of lens

constriction of pupils

convergence of eyes

refraction

bending of light rays at junction between two transparent substances with different densities

osteogenic cells

undifferentiated cells

divide and become osteoblasts

inner layer of periosteum and endosteum

osteoblasts

immature bone cells

form and secrete ecm

osteocytes

mature cells no longer secreting ecm

main cells in bone

cells lie within lacunae

osteoclasts

very large cells with several nuclei

derived from fusion of monocytes

mostly in endosteum

function in bone resorption

diaphysis

bone shaft

epiphysis

end of long bone

metaphysis

growth (epiphyseal) plate region

articular cartilage

hylaine cartilage over joint surfaces

reduces friction and absorbs shocks

medullary cavity

yellow bone marrow cavity

endosteum

inside lining of medullary cavity

bone cells

periosteum

tough membrane covering bone

outer fibrous layer made of ct

inner osteogenic layer

protects and nourishes bone

attatchment point for ligaments

compact bone tissue

strongest bone tissue

makes up frame of long bones

resists stress produced by weight and movement

provides support and protection

osteons

repeated units

concentric lamellae around central canal

osteocytes

located in lacunae

communicate via canaliculi

spongy bone tissue

light bone tissue inside a boen

protected by compact bone

area of low stress from many directions

ends of long bones

inside of flat and short bones

supports and protects bone marrow

trabeculae

spongy bone

latticework of thin plates

concentric lamellae with osteocytes in lacunae

three types of cartilage

hylaine, fibrocartilage, elastic cartilage

hyaline cartilage

support and reinfoece resist compressive stress

location of hyaline cartilage

covers ends of long bones in joint cavities,; costal cartilage of rivs; cartilage of nose, trachea and larynx

fibrocartilage

tensile strength allows it to absorb comprehensive shock

location of fibrocartilage

intervertebral discs, pubic symphsis; menisci of knee joint

elastic cartilage

maintains shape of a structure while allowing great flexibility

location of elastic cartilage

supports the external ear, epigilotis

5 major types of bone

long, short, flat, irregular, sesamoid

axial skeleton

80 bones

midline bones

appendicular skeleton

126 bones

along limbs

vertebral collumn

26

cervical -7

thoracic - 12

lumbar - 5

sacrum- 5

coccyc, 4

synarthrosis

non-moveable

amphiarthrosis

slightly moveable

dairthrosis

freely moveable