OPT1210 Exam 1 Flashcards
Greek word for thought/word
logos
What is the study/science of eyes?
Ophthalmology
What does the field of ophthalmology encompass?
Anatomy Physiology Optics Pathology Pharmacology Medicine Surgery
What is the eye?
The brain
What are the 5 senses and nerves that sense them?
Hearing - auditory nerve
Smell - cranial nerve 1 (olfactory nerve)
Touch - proreceptive nerves all over body
Taste - sensory nerves in tongue
Vision - cranial nerve 2 (optic nerve)
What is the body’s most important organ?
Eyes
85% of everything we have learned came through our eyes
Are our eyes the same?
Eyes are bilaterally symmetrical
What interprets visual imagery and makes sense of it?
Occipital cortex
What is the clarity with which you see called?
Visual acuity
What is the comparison between an image and its surroundings called?
Contrast
Why do some people get carsick?
Vestibular-ocular mismatch
The sense of movement is fooled by what the eye sees
Structures of eye and orbit
Pupil Iris Sclera Upper and lower eyelids Caruncle
How do you produce tears?
Blinking
The eyelids
Lacrimal apparatus
What parts of eye have focusing power?
Cornea - 85% of focusing power
Crystalline lens - 15% of focusing power
Extra ocular anatomy
Six extra ocular muscles (4 recti; medial rectus is widest)
Conjunctiva - covers sclera
Cornea - corneal-scleral junction is limbus
Iris - colored part of eye
Intra ocular anatomy
Crystalline lens and Zonules - threads that connect/control movement of lens
Fluids (aqueous and vitreous)
Retina
Greek word for eye
ophthalmos
Intra ocular fluids
Aqueous humour - anterior chamber
Vitreous gel - posterior chamber
Rods are responsible for what?
Scotopic night vision
Cones are responsible for what?
Photopic day vision
What contains 4000 cone cells (no rods)?
Fovea
What wavelengths do cones perceive?
Red
Green
Blue
Pathway of light
Through tear film cornea, aqueous humour lens vitreous cavity to stigma (single point of focus)
optic nerve
one for each eye
optic chiasm
1/2 of vision in each eye goes to each side of brain
occipital cortex
LGN, optic radiation, primary visual cortex (occipital lobes)
How many bones make up orbit?
7
Principle of Refraction
Snell’s Law
Light is bent as it passes from a less dense to a more dense medium
What is 20/20?
normal vision: emmetropia
What is Nearsightedness?
Myopia
What is Farsightedness?
Hyperopia
What is Blurry focus?
Astigmatism
What does a Phoropter measure?
Lens power
What is an ICL?
Implantable Contact Lens
What are the top five causes of blindness?
Age-related macular dengeneration Cataracts Diabetic retinopathy Glaucoma Corneal opacification
What is a cataract?
A Clouding of the natural lens of the eye.
How are cataracts repaired?
Cataract surgery Topical anesthesia Microincision Capsulorrhexis Phacoemulsification Irrigation and Aspiration of Lens Cortex Implantation of Intraocular Lens (IOL)
What is glaucoma?
An increase in intraocular pressure that damages the optic nerve. It reduces peripheral vision.
What are the diseases of the Retina?
Age-related macular degeneration
Diabetic retinopathy
Front
Anterior
Back
Posterior
Top
Superior
Bottom
Inferior
Middle
Median or Medial
Adjacent to Middle
Paramedian
To the Side
Lateral
Around
Peri
Between
Inter or Intra (within)
Divides body into right and left halves
Saggital plane
Medial
Longitudinal
Divides body into front and back
Coronal or Frontal plane
Cross-section
Divides body into upper and lower
Transverse plane
Horizontal
Chemical hierarchy
Atom Molecule Organelle Cell Tissue Organ System
What is a chemical element?
The simplest form of matter with unique chemical properties
Structure of an Atom
Nucleus - center of atom Has protons (+ charge) and Neutrons (no charge) Electron shells surround nucleus and have a - charge
How many elements have a biological role and which elements comprise 98.5% of body weight (or the eye)?
28 elements have a biological role. 6 most prevalent in body: Hydrogen Carbon Nitrogen Oxygen Phosphorus Calcium
What is an ion?
An atom with a + or - charge
What is an Anion?
An atom with a - charge that has gained an electron
What is a Cation?
An atom with a + charge that has lost an electron
What cells are thin and flat and found on the surface?
Squamous
What cells are irregularly angular with 4 or more sides and need to make contact with other cells?
Polygonal
What cells are square and for stacking/structure?
Cuboidal
What cells are rectangular (taller than wider)?
Columnar
What cells are round and need to roll or be in motion?
Spheroid
What cells are disc-shaped (taco shaped) and need to squeeze through openings?
Discoid
What cells have spikes and need to stay in contact with other cells?
Stellate
What is a long peptide chain made of the 26 amino acids?
Membrane proteins
Comprise 2% of cell membrane but 50% of its weight
What cells need to stretch and contract?
Fusiform
What cells need to provide structure?
Fibrous
What are the 3 ways things are transported through membrane?
Passive transport - goes through on own
Active transport - requires energy to go through
Osmosis - movement of water across a membrane
What cells have a cell membrane?
Human eukaryotic cells
What are cell membranes comprised of?
Lipid bilayer with Polar (phosphate heads)
What is tonicity?
Ability of a solution to affect fluid volume and pressure within a cell
Deals with concentration of salt
What is Isotonic?
Same concentration of salt outside and inside
Cell size does not change
Normal saline is same as body tissue composition
What is normal saline?
0.9% NaCl in 1 liter of water
What is Hypotonic?
Low concentration of salt 0.45% NaCl (1/2 normal saline)
Cells absorb water, swell and burst (lyse)
What is Hypertonic?
High concentration of salt >0.9% NaCl
Cells lose water and shrivel (crenate)
What are chromosomes?
Tightly wound package of genetic material
46 DNA molecules (23 pairs + 1 pair sex chromosomes)
What is the structure of DNA?
Polymer of nucleotides
Phosphate - backbone of purine or protomine
Sugar - deoxyribose
Deoxyribose - Nitrogenous base
What is a gene?
Codes for one protein
What is a genome?
All the genes of a person (30,000 -35,000)
98% of DNA is “junk” or regulatory (turns other genes on or off)
All humans are 99% genetically identical
What is a normal karyotype?
Distribution of 23 pairs of chromosomes of cell (seen only in metaphase)
What was the Human Genome Project?
Race to map entire base sequence (A, T, C, G)
1990-2003
Watson and Crick
What are dominant alleles?
Produce protein responsible for visible trait
Phenotype
What are recessive alleles?
Expressed only when both alleles are recessive
What are 2 or more loci contributing to a single phenotypic trait?
Polygenic inheritance
e.g. skin color, eye color, alcoholism, heart disease
What is the study of tissues?
Histology
What is a collection of similar cells that arose from the same region of embryo?
Tissue
How many cell types are in the human body?
200
What are the four classes of tissue?
Epithelial
Connective
Muscular
Nervous
What is the study of tissues for organ formation?
Microscopic anatomy
What are composed of two or more different types of tissues and form “discrete boundaries”?
Organ structures
What is the beginning of the development of a human being from a cell?
Embryogenesis
How many germ cell layers of embryonic disc are there? What are they?
Three;
Ectoderm
Mesoderm
Endoderm
From what germ cell layer does Neural: RPE, retina, iris muscles and optic nerve and Surface: Lens, epithelium, and lacrimal gland originate?
Ectoderm
From what germ cell layer does bones, muscle, cartilage, blood, and lymphoid tissue originate?
Mesoderm
From what germ cell layer does gut and respiratory epithelium and glands originate (not ocular)?
Endoderm
What is the “strings and glue” that holds cells together?
Fibrous proteins
Ground substance
How do you prepare a histological specimen?
Fixative prevents decay (Formalin)
Embedded in paraffin wax
Sliced into thin sections 1 or 2 cells thick
Stained to show cellular components
Placed on glass slide and covered for viewing under microscope
What does epi- mean?
on top
What does -thelium mean?
tissue
What are the characteristics of epithelium?
Layers of closely adhering cells
No blood vessels
Underlying connective tissue supplies oxygen
Rests on basement membrane (basal cells) that
anchors epithelium to connective tissue
What is simple epithelium?
one layer of cells simple squamous (flat)
What is simple cuboidal epithelium?
single row of cube-shaped cells - formed to create a conduit (ducts)
What is simple columnar epithelium?
Single row of tall, narrow cells - formed where absorption occurs (the lining of the gut)
What is stratified epithelia?
more than one layer of cells
What is pseudostratified epithelia?
more than one layer of cells of different sizes and shapes
Where are keratinized cells located?
In outer layer (hair, skin, nails)
dead cells
Where is thickest skin located?
Soles of feet and palms of hands
What allows cells to communicate and allows passage between them?
Intercellular junctions
What holds cells together?
Connective Tissue
What is the most abundant and variable tissue in the human body?
Connective Tissue
What is connective tissue?
Widely spaced cells separated by fibers and ground substance
What is the most abundant connective tissue in the body?
Soft areolar tissue
What do adipocytes do?
Store triglycerides
What is around eye that lets it move freely?
adipose tissue and orbital fat
Adipose cells have what pushed to cell membrane?
nucleus
What cells are in connective tissue?
Macrophages - phagocytize foreign material and activate immune system and arise from monocytes (WBCs)
Neutrophils - prevent infection, deployed to site of injury
Plasma cells - synthesize antibodies
Mast cells - induce inflammation (heparin & histamine)
What fibers are in connective tissue?
Collagen - largest macro molecule in body, tough, stretch resistant
Elastin - specialized form of collagen, stretches
Ground substance
What are the types of muscle tissue?
Skeletal - long, striated, powerful, most prevalent
Cardiac - intercalated disks, only in heart, never rests
Smooth - involuntary, control orafices, tubes, vessel walls
Where is skeletal muscle in the eye?
ocular muscles
Where is smooth muscle in the eye?
Iris - short fusiform cells
What is replacement of damaged cells with original cells called?
Regeneration
What is replacement of damaged cells with scar tissue called?
Fibrosis
How are wounds healed?
Damaged vessels leak blood Histamine is released to induce inflammation clot forms scab forms macrophages clean up debris new capillaries grow fibroblasts deposit new collagen epithelial cells multiply scab falls off epithelium thickens connective tissue forms
Can all ocular tissues heal?
No
Lens and Retina cannot
Most heal by fibrosis and scarring (associated with a loss of function)
What are the 12 organ systems?
Integumentary Skeletal Muscular Lymphatic Respiratory Urinary Nervous Endocrine Circulatory Digestive Reproductive (Male and Female)
What is the largest organ in the human body?
Skin (15% of body weight)
Where is the thinnest skin in the human body?
Eyelid
What are the layers of the skin?
Epidermis (from Ectoderm)
Dermis (from Mesoderm)
Connective Tissue Layer
Hypodermis
What produces alpha keratin - the tough outer coat of the skin, hair and nails and comprises 85% of all skin cells?
Keratinocytes
What synthesizes pigment that shields UV light?
Melanocytes
What are the layers of the Epidermis?
Stratum Corneum
Stratum granulosum
Stratum spinosum
Stratum basale
Where does a subcutaneous injection go?
Between the dermis and epidermis
about a 3/8 inch needle
Where does an intradermal injection go?
In the dermis
Where does a hypodermic injection go?
In the hypodermis to be picked up by the blood supply
about a 3/4 inch needle
Where does a intramuscular injection (depo injection) go?
In the muscle below the hypodermis
Give this type if want med to sit there
What may someone with a hemangioma on the left side of the face, near the eye, be at risk for?
Glaucoma (increased pressure)
What is a hemangioma?
An abnormal growth of vessels (capillary bed) in hypodermis
How much exposure to UV light is safe?
None
What makes up bone?
Osseous matrix:
1/3 organic (collagen, glycosaminoglycans, proteoglycans and glycoproteins)
2/3 inorganic (85% hydroxyapatite, 10% calcium carbonate, Fluoride, Potassium and Magnesium)
What are the two divisions of the skeleton?
Axial (trunk) 80 bones
Appendicular (limbs) 132 bones
How many bones in human skeleton?
Adult 212
Birth 270
What bones comprise the axial skeleton?
Central axis Skull Vertebral column Ribs Sternum Sacrum Coccyx
What bones comprise the appendicular skeleton?
Four Girdles - Shoulders and Pelvic
Arms and Legs
What are the functions of membrane proteins?
Receptors Enzymes Channel proteins (gates) Identity markers Adhesion molecules
In which layer of epidermis are cells dead, keratinized and up to 30 layers thick (7 layers in eyelids)?
Stratum Corneum
In what layer of epidermis do cells begin to lose nuclei, are 3-5 layers of keratinocytes and are hydrophobic (create a waterproof barrier)?
Stratum granulosum
What layer of epidermis is dendritic, has Langerhans cells and macrophages?
Stratum Spinosum
What layer of epidermis sits on basement membrane, has melanocytes, Merkel cells and is the origin of basal cell carcinoma?
Stratum Basale
