STDs, UTIs, Protein Synthesis Inhibitors, Intro to Eye (Week 4)

Question 1

Bacterial STDs

Answer 1

Most are curable!

Neisseria gonorrhoeae, Chlamydia trachomatis, Treponema pallidum (syphilis), Klebsiella granulomatis, Haemophilus ducreyi

However, complications if untreated (PID; epididymitis; syphilis becomes chronic)

Question 2

Reporting STDs

Answer 2

Syphilis: report and try to track down partners

Chlamydia and gonorrhea: report (?) but don’t track down partners

Question 3

Sequelae of N. gonorrhoeae and C. trachomatis

Answer 3

Urethritis (urethral inflammation): dysuria, discharge, WBCs, leukocyte esterase positive

Cervicitis (cervical inflammation): asymptomatic; vaginal bleeding, discharge, friable cervix

Question 4

Most common bacterial STD

Answer 4

Chlamydia trachomatis

(reportable)

Question 5

Chlamydia

Answer 5

Requires columnar epithelial cells

Young people more prone, because have more columnal epithelial cells

Beefy red cervical mucosa, follicular changes “cobblestoning”

Women: Cervicitis, urethritis, conjunctivitis (auto-inoculation) –> PID, peri-hepatitis (Fitz-Hugh-Curtis)

Men: Urethritis, proctitis, conjunctivitis (auto-inoculation) –> epididymitis, reactive arthritis

Question 6

Pelvic inflammatory disease (PID)

Answer 6

Can be acute or silent

A result of untreated chlamydia or gonorrhea

Infection of entometrium (endometriosis), fallopian tubes (salpingitis), pelvic peritoneum (Fitz-Hugh-Curtis syndrome w/violin strings)

Adnexal pain, easily provoked cervical bleeding, elevated ESR or CRP

Diagnose with imaging or laparoscopy

Leads to ectopic pregnancy because of scarring, infertility because of fallopian tube occlusion, chronic pelvic pain

Question 7

Reiter’s syndrome (reactive arthritis)

Answer 7

Complication of chlamydia

Oligoarthritis (swelling and tenderness in mult joints)

Circinate balantis (scaling erythematous plaques on penis)

Autoimmune reaction associated with HLA B27

Question 8

Lymphogranuloma venereum (LGV)

Answer 8

Serotypes L1, L2, L3 of chlamydia causes this

Enters lymphatics, replicates in macrophages –> inguinal lymphadenitis –> proctocolitis

Groove sign: enlarged inguinal and femoral nodes separated by ligament of Poupart

Question 9

Neonatal chlamydia

Answer 9

Note: not one of “ToRCHeS” but mother can still give to child during birth

Conjunctivitis, pneumonia

Question 10

Diagnostic tests for chlamydia

Answer 10

Chlamydia is INTRACELLULAR organism, so need to culture cells

However, now we can do nucleic acid amplification testing (NAAT) just using urine specimens: PCR, LCR, TMA, SDA

Question 11

Treatment for chlamydia

Answer 11

Azithromycin 1g PO x 1

Doxycycline 100mg PO BID x 7 days

Patient delivered partner therapy

Question 12

Gonorrhea

Answer 12

Facultative intracellular (can be inside or out of cells)

Infects noncornified epithelium

Formation of submucosal abscesses and accumulation of exudate in lumen

Women: cervicitis, urethritis, proctitis, pharyngitis, skene/bartholin gland infection –> PID, Fitz-Hugh-Curtis, disseminated infection

Men: urethritis, epididymitis/seminal vesiculitis, proctitis, conjunctivitis, abscess of Cowper’s/Tyson’s glands, pharyngitis –> disseminated gonococcal infection (DGI), urethral stricture, penile edema

Question 13

Disseminated gonococcal infection (DGI)

Answer 13

Gonococcal bacteremia

Symptomatic or asymptomatic infection of pharynx, urethra, cervix

<5% of GC infected people

Complement deficiency (C7, 8, 9) means higher risk for this

“Arthritis-dermatitis syndrome” with polyarthritis and sterile tenosynovitis and skin lesions

Question 14

Neonatal gonorrhea

Answer 14

Not one of “ToRCHeS” but vertical transmission during birth (30%) if no prophylaxis

Ophthalmia neonatorum, DGI, vaginal/rectal/pharyngeal infections

Question 15

Diagnostic tests for gonorrhea

Answer 15

Gram stain, culture, DNA probe, NAATs using urine

Question 16

Treatment for gonorrhea

Answer 16

Ceftriaxone IM (injection) x 1

PLUS

Azithromycin 1g PO x 1 or doxycycline 100mg PO BID x 7d (same as chlamydia, but also enhanced activity against gonorrhea!)

DON’T use fluoroquinolones (resistance) or cefixime (anaphylactic shock)

Question 17

Epididymitis

Answer 17

Complication of gonorrhea or chlamydia in men; also from UTI

Unilateral testicular pain/swelling, usually accompanied by urethritis

Question 18

Genital ulcer disease

Answer 18

STD causes: herpes simplex, syphilis, chancroid, lymphogranuloma venereum, granuloma inguinale

Non-STD causes: Candida balanitis, impetigo, trauma, Bechet’s syndrome, fixed drug eruption, malignancy, contact dermatitis

Question 19

Vaginitis

Answer 19

Trichomonas vaginalis (parasite)

Related to sexual activity, but not clearly transmitted sexually

Question 20

Tetracyclines mechanisms of resistance

Answer 20

1) Bacteria alter outer membrane porin proteins so decreased influx of drug into bacteria
2) Bacteria do active transport out of cell by pump proteins

Question 21

Tetracycline considerations regarding food, etc

Answer 21

Do not take tetracycline with dairy (calcium) because will form chelates so cannot be absorbed

Do not give tetracycline to pregnant women (bc of effect on fetus) or children under 8 whose teeth have not formed because will stain teeth brown

Take with full glass of water because can cause gastric discomfort if stuck in esophagus

Causes phototoxicity, dizziness, liver failure

Can cause superinfection (because broad spectrum)

Question 22

Tigecycline

Answer 22

Clycylcycline class of protein synthesis inhibitors

IV administration only

Very broad spectrum (gram +, gram -, anaerobes MRSA, VRE, MDR acinetobacter)

Good for intra-abdominal infection (Enterococci, E. coli, Klebsiella, Bacteroides fragilis)

NOT Pseudomonas aeruginosa

Question 23

Mechanisms of resistance to aminoglycosides

Answer 23

Bacteria can:

1) Alter uptake mechanisms to decrease influx of drug into bacteria
2) Alter target (mutate 30S ribosome)
3) Enzymatic modification to phosphorylate, adenylate, acetylate the drug to make it inactive

Question 24

Dosing of aminoglycosides

Answer 24

Exhibit concentration dependent killing: bactericidal activity proportional to peak concentration (so want peak conc as high as possible)

Have post-antibiotic effect (drug works even after levels are below MIC)

Toxicity less with once daily dosing

Give one single high dose per day

Question 25

Pharmacokinetics and toxicities of aminoglycosides

Answer 25

Only used IV, IM or topically (poor absorption in GI) Polar, bad CSF penetration High levels in **urine** because excreted there so good for treating **UTIs** Also get into blood so good for **gram - septic shock** Toxicities: **nephrotoxicity** and **ototoxicity**

Question 28

Adverse effects of macrolides

Answer 28

**Epigastric** **distress** (worst with erythromycin) Cholestatic jaundice Ototoxicity (rare) QT prolongation Adverse **drug** interactions because interfere with CYP450 clearance

Question 31

Mupirocin

Answer 31

AKA Bactroban, pseudomonic acid A Active against **gram +** bacteria including **MRSA** Used **topically** **only** Used **before surgery** to prevent MRSA into open would

Question 32

Drugs for anaerobic infections

Answer 32

**Clindamycin** Chloramphenicol Tigecycline **Penicillins** **Piperacillin/tazobactam** Ampicillin/sulbactam Amoxicillin/clavulanate 2nd generation cephalosporins (**cefoxitin, cefotetan**) **Carbapenems** **Moxifloxacin**

Question 33

Treatments for specific anaerobic infections

Answer 33

Anaerobic **streptococci**: **penicillin** **Oropharyngeal** **GI** infections (head and neck abscess): **clindamycin**, penicillin, penicillin + beta lactamase inhibitor **Intestinal** **GI** infections (ruptured appendix): **metronidazole**, cefoxitin, cefotetan, carbapenem, penicillin + beta lactamase inhibitor, clindamycin Abscesses: metronidazole, chloramphenicol

Question 33

Causative organisms for UTI in women

Answer 33

**E. Coli** **S. saprophyticus** P. mirabilis, Klebsiella, Pseudomonas, Serratia, Enterococcus, yeast

Question 34

Uropathogenic E. coli (UPEC)

Answer 34

A few serotypes of E. coli cause UTI Virulence factors specific/important to UPEC: **adhesins** (type 1 fimbriae, P fimbriae) Contains **pathogenicity-associated islands** (PAIs) which contain clusters of virulence factor genes Pathogen has to **stick** in order to infect you (or else you'd pee it out)

Question 35

Type 1 Fimbriae

Answer 35

One of two adhesins important to UPEC Rod-like polymer of **FimA** with one **FimH** on the tip which adheres to mannose-containing uroplakin proteins on bladder uroepithelial cells **Cystitis**

Question 36

P Fimbriae

Answer 36

Adhesin that helps E. coli (UPEC, specifically) bind to uroepithelial cells Pyelonephritis-associated pilus (pap) gene cluster has 11 genes **PapG adhesin** subunit at tip binds glycolipids on uroepithelial cells of kidney --\> causes pyelonephritis P fimbriae is important vaccine target **Pyelonephritis**

Question 37

Host defense mechanisms against UTI

Answer 37

Unobstructed **flow** of urine (flush out anything that tries to colonize) Normal urine **characteristics** (osmolality, urea concentration, pH, etc) Tamm-Horsfall glycoprotein (**THP**) produced by ascending loop of Henle and DCT, mannose rich residue secreted into urine

Question 38

Host susceptibility to UTI

Answer 38

**Obstruction** to urine flow **Neurogenic** bladder (incomplete emptying) **Renal calculi** **Sexual activity** **Antibiotic therapy** (altered flora) **Diabetes** (glucose in urine) **Low estrogen** (post-menopause) makes it easier for bacteria to attach to cells

Question 39

Urinalysis for UTI

Answer 39

**10 WBC/high power field** = **pyuria** = evidence for inflammatory response **RBCs** = evidence for damage to uroepithelium **Gram stain** = evidence for bacteria in urine

Question 40

2 lab tests used together to diagnose UTI

Answer 40

**Leukocyte esterase** (suggests WBCs in urine) **Nitrite** (suggests bacteria in urine)

Question 41

Cystitis vs. pyelonephritis

Answer 41

**Cystitis**: bladder infection **Pyelonephritis**: kidney pelvis infection (have abscess formation in kidney; costovertebral-angle tenderness; fevers, chills, nausea) and can lead to sepsis or death

Question 42

What else can present with burning on urination?

Answer 42

Urethritis due to **N. gonorrhoeae**, **chlamydia**, **HSV** This is NOT a UTI

Question 43

Should you get a culture when you suspect UTI?

Answer 43

Only if you suspect **pyelonephritis** since that is dangerous No need to culture for uncomplicated cystitis

Question 44

What can cause kidney stones?

Answer 44

Bacteria produces **urease** --\> splits urea into **ammonium hydroxide** --\> raises urinary pH --\> precipitation of **struvite** and **apatite stones** in bladder and kidney --\> obstruction of urine flow Intervention to **relieve** pressure in order to preserve renal function **Urease +**: **Proteus** mirabilis, **S. saprophyticus**, **K. pneumoniae**, C. urealyticum

Question 45

Asymptomatic bacteriuria

Answer 45

Positive bacterial culture from appropriately collected sample in patient with no symptoms **Only treat pregnant women** (reduce risk of pyelonephritis which would be bad because hard to treat pregnant women!)

Question 46

Drugs to treat uncomplicated UTI

Answer 46

**Trimethoprim-sulfamethoxazole** BID x 3 days **Nitrofurantoin** 100mg BID x 5 days

Question 47

Nitrofurantoin

Answer 47

AKA **Macrobid** 100mg No tissue penetration, so use only for **cystitis** Proteus and Klebsiella resistant Safe in pregnancy Can cause **severe lung injury**: acute presenting like **allergy**, or chronic **interstitial fibrosis**

Question 48

Fosfomycin

Answer 48

To treat **uncomplicated** **UTIs** Activity against **VRE**, ESBL producing E. coli, some **MDR** **Pseudomonas** aeruginosa, few **MDR** **Acinetobacter** baumanii

Question 49

Fluoroquinolones for UTI

Answer 49

**Don't** use them for uncomplicated UTIs because you need them for more serious infections (pyelonephritis)

Question 50

Risk of "collateral damage" or producing resistance by using these drugs

Answer 50

**High**: TMP-SMX, fluoroquinolones, beta-lactams **Low**: nitrofurantoin, fosfomycin, pivmecillinam

Question 51

Inpatient treatment of pyelonephritis

Answer 51

**3rd generation** **cephalosporin** +/- aminoglycoside Extended spectrum **penicillin** +/- aminoglycoside **Carbapenem** +/- aminoglycoside

Question 52

Outpatient treatment of pyelonephritis

Answer 52

PO **fluoroquinolone** +/- IV aminoglycoside one time **Ciprofloxacin** better than TMP-SMX

Question 53

How to deal with pyelonephritis

Answer 53

Get a **urinalysis** and **culture** for all patients with pyelonephritis **CT** scan for anyone with **history of renal colic** If **fever** persists after **72** **hours**, **reculture** because might be missing a pathogen and do **radiological** **studies**

Question 54

Mechanisms of resistance to fluoroquinolones

Answer 54

Mostly due to **alteration in subunits** of DNA gyrase or topoisomerase IV Less commonly decreased outer membrane **permeability**, activation of **efflux pumps**

Question 55

Adverse effects of fluoroquinolones

Answer 55

**GI upset** is most prominent side effect Dizziness with moxifloxacin, **tendinopathy** (achilles tendon rupture), hepatotoxicity, hyper/hypoglycemia **Contraindicated in pregnancy** and in **children** due to cartilage toxicity

Question 56

Pharmacokinetics of fluoroquinolones

Answer 56

Well absorbed but **don't give with Ca2+, Fe, Mg2+** because it will inhibit absorption Concentration in kidney and urine is high (good for **UTIs**!), CSF levels lower than plasma Hepatic metabolism clears 20% and the rest excreted in urine (good for UTIs!)

Question 57

Adverse effects of methenamine

Answer 57

**GI distress** Contraindicated in patients with renal dysfunction, hepatic dysfunction Don't give with sulfonamides because will inactivate both agents

Question 58

Daptomycin

Answer 58

**Inserts K+ channel** into bacterial **cell membrane** to disrupt electrochemical gradient --\> bactericidal Active against many **gram +, MRSA, VRE** NOT active against gram - Used for skin infection, bacteremia, right sided endocarditis; NOT for pneumonia bc inactivated by surfactant Doesn't break open bacteria like beta-lactams do so might use this if worried about that

Question 59

Chlamydiaecea

Answer 59

**Chlamydia** **trachomatis** **Chlamydophila** **pneumoniae**, **Chlamydophila** **psittaci** **Obligate intracellular** Gram - but LPS does not cause cytokine storm! **No peptidoglycans of cell wall** so beta lactams don't work!

Question 60

Treatment for chlamydia

Answer 60

**Azithromycin (macrolide) 1g PO x 1 day** Doxycycline (tetracycline) 100mg BID x 7 days Quinolones x 7 days

Question 61

Chlamydophila pneumoniae

Answer 61

Pharyngitis, bronchitis **Atypical** **pneumonia** (interstitial infiltrates, n**on-productive cough**) Otitis media, endocarditis (rare)

Question 62

Mycoplasma and Ureaplasma

Answer 62

M. pneumoniae, M. hominis, M. genitalium, U. urealyticum **Smallest** bacteria **Lack rigid cell wall** Diagnosis: NAAT, serology, **cold hemagglutinin** Treatment: **tetracyclines**, **macrolides**, **quinolones** (NOT cell wall agents!)

Question 63

M. hominis, M. genitalium, U. urealyticum

Answer 63

Cause of non-gonococcal **urethritis**

Question 64

Rickettsiae

Answer 64

**Rickettsia**, Orientia, **Coxiella**, Anaplasma Infect vascular endothelial cells, and other cells **Arthropod vector** transmission for **Rickettsia**, Orientia, Anaplasma **Goats, sheep** etc transmission for **Coxiella**

Question 65

Anaplasmosis (Ehrlichiosis)

Answer 65

**Tick vector** Similar to **RMSF** **without a rash** (headache and fever) Infects leukocytes; monocytic, granulocytic; doesn't infect vascular endothelium so no rash! Treatment: doxycycline/chloramphenicol

Question 66

Endemic (murine) typhus

Answer 66

**Rickettsia typhi** **Rats** with **fleas** are reservoir --\> fleas bite humans accidentally Abrupt onset fevers, chills, headaches, myalgias Milder than RMSF and resolves **without treatment** Treatment: doxycycline or chloramphenicol, if necessary

Question 67

Tpr membrane proteins

Answer 67

Proteins on surface of **Treponema** **pallidum** that **change** variable region so immune system cannot catch them!

Question 68

Stages of syphilis

Answer 68

Incubation: 21 days **Primary** syphilis: 3-6 weeks; **painless** **chancre** w/raised borders **Secondary** syphilis: 2-8 weeks after chancre appeared; dissemination, **condyloma** **lata**, **maculopapular** **rash** on **palms and soles**, **meningitis**, hepatitis, **arthritis** **Latent** syphilis: early or late (1 year cutoff) **Tertiary** (late) syphilis: **gummas**, **cardiovascular** (aortitis, aortic aneurysm), **neurosyphilis** (meningiovascular, general paresis, tabes dorsalis, Argyll Robertson pupil)

Question 69

Serodiagnosis of syphilis

Answer 69

**Nonspecific** (nontreponemal) tests: **VDRL**, RPR; used as **screening**, titer measures disease activity, response to therapy; antibody to cardiolipin (lipid found in normal tissues); false positive reactions in SLE **Specific** (treponemal) tests: **FTA-ABS**, MHA-TP; antibody to specific antigens of T. pallidum; used to **confirm** positive VDRL or RPR

Question 70

How do you treat syphilis if patient is allergic to penicillin?

Answer 70

**Desensitize** to penicillin (especially if patient is pregnant) Doxycycline, ceftriaxone, chloramphenicol

Question 71

Interaction between syphilis and HIV

Answer 71

Patients with syphilitic lesions more **susceptible** to acquiring **HIV** Co-infected patients more likely to **transmit** both HIV and syphilis **Co-infected** patients have more **malignant** **course** of syphilis Syphilis **relapses** after adequate therapy in co-infected individuals

Question 72

Nonvenereal treponematoses

Answer 72

**Yaws**: T. pallidum (**pertenue**) in humid tropics, transmitted skin to skin, **papules**, **gummas** of bone and skin **Pinta**: T. carateum in arid Americas, transmitted skin to skin, **papules**, **achromic** **macules** **Bejel**: T. pallidum (**endemicum**) in arid Africa, transmitted mouth to mouth, **oral** **lesions**, **gummas** of bone and skin

Question 73

Borrelia vsp expression

Answer 73

**vsp** = variable surface protein Moves antigenic genes around by recombination to produce **different vsp proteins** to **evade** immune response! Borrelia recurrentis, Borrelia hermsii

Question 74

Relapsing fever

Answer 74

**Borrelia recurrentis** spread by **lice**; higher fatality **Borrelia hermsii** and others spread by **ticks**; lower fatality Fever, chills, headache, myalgias, sweats, **febrile relapses**

Question 75

OspA

Answer 75

**OspA** = outer surface protein On **Borrelia burgdorferi** (in tick midgut) OspA helps bacteria stay **attached** to tick midgut but as tick sucks blood from mouse, **temperature rises** and that causes OspA to be **downregulated** Also increase in temperature **upregulates** **OspC** which is important for Borrelia burgdorferi life in the mouse

Question 76

Do we have a vaccine for B. burgdorferi?

Answer 76

No Tried to give antibodies to OspA because it kills B. burgdorferi before it can get into humans and infect them, but was shown to induce autoimmune arthritis (very bad side effect!)

Question 77

Stages of Lyme disease

Answer 77

**Stage 1**: localized infection; **erythema chronicum migrans** (target) around bite location, **flu-like** symptoms **Stage 2**: **disseminated** infection; secondary annular skin lesions, pain in **joints**, tendons, lymphocytic meningitis, cranial neuritis (**Bell's palsy**), radiculoneuropathy, **AV nodal block** **Stage 3**: persistent infection; intermittent **attacks of joint swelling** and pain primarily in large joints (knee; 1 or 2 joints at a time)

Question 78

Indications for testing for Lyme disease

Answer 78

**Migratory pain in joints**, tendons, brief attacks of arthritis Lymphocytic **meningitis**, cranial neuritis (facial palsy), radiculoneuropathy **AV nodal block** All the serious symptoms...

Question 79

How do you prevent Lyme disease

Answer 79

Can wear **clothing** with **permetherine** in it Check for ticks! **Early detection and removal** of tick within 24 hours can prevent disease Prophylactic **doxycycline** 200mg if **engorged tick** is found

Question 80

Leptospira weilii

Answer 80

**Spirochete** wound in thin tight coil Lives in renal tubules of host (rodent, dog, fish, bird), shed in **animal urine**, transmitted to humans via contaminated water (**surfers** get this) **First/septicemic (leptospiremic) phase**: 3-7 days; bacteria invade blood and CSF; high **fever**, **headache**, malaise, myalgia, abdominal pain, **conjunctival** **suffusion** (red), **photophobia** **Second (immune) phase if ANICTERIC**: 0-1 month; milder **fever**, **headache**, **vomiting**, aseptic **meningitis** **Second (immune) phase if ICTERIC** (**Weil's Syndrome**): **jaundice**, **renal** **failure**, hypotension, **hemorrhagic pneumonitis**, **mortality** 5-40%

Question 81

Do spirochetes have toxins?

Answer 81

No!

Question 82

Which innate immune response mechanism recognizes leptospiral LPS?

Answer 82

**TLR-2** Usually LPS recognized by TLR-4, but leptospiral LPS is different!

Question 83

3 layers of tear film

Answer 83

1) **Lipid** layer 2) **Aqueous** layer (composed of proteins) 3) **Glycocalyx** (covers surface of cornea)

Question 84

Where do lipids come from?

Answer 84

**Meibomian oil** at the meibomian orifice

Question 85

Where do tears come from?

Answer 85

**Lacrimal gland** Note: tears protect you because they contain **immunoglobulins**

Question 86

Dry eye disease

Answer 86

Most **common** eye disease

Question 87

Conjunctiva

Answer 87

Conjoins **cornea to eyelid** at the **limbus** **Non-keratinized stratified squamous epithelium** with **goblet cells** (which produce mucin 5AC which goes into tear film and is very protective) **Clear** so you can't see it, but **contains blood vessels** that you can see

Question 88

Squamous carcinoma of the eye

Answer 88

Gelatinous layer that **covers surface of cornea** (so can't see well) Most **common** **malignant** disease

Question 89

Cornea

Answer 89

Central visual axis, must remain clear for good vision Key refractive surface **5 layers**

Question 90

5 layers of the cornea

Answer 90

1) Epithelium 2) **Bowman's layer** 3) **Stroma** (most of the thickness of cornea) 4) **Descemet's membrane** 5) Endothelium

Question 91

Infectious corneal ulcer

Answer 91

Most **common** disease of cornea Most common reason for this disease is **contact lens** wearing Can perforate through eye, through stroma and can lose eye if not treated rapidly

Question 92

Lens

Answer 92

Behind iris **Grows** for your entire life Lens fibers surrounded by **thin capsule** Most common disease of lens is **cataract**

Question 93

Cataract

Answer 93

Precipitation of aggregation of **lens crystalline proteins** **Opaque**, so can't see through it

Question 94

Anterior chamber

Answer 94

Bounded by **cornea** **anteriorly**, **iris posteriorly**, scleral spur, ciliary body Key structures for **aqueous drainage**: **Schlemm's canal** and **trabecular meshwork**

Question 95

Uvea

Answer 95

Contains **iris, ciliary body** and **choroid** Contains **melanocytes** to absorb scattered light and give you a good view

Question 96

Iris

Answer 96

Anterior border layer Stroma **Constrictor muscle** **Dilator muscle** Posterior pigmented epithelium

Question 97

Ciliated body

Answer 97

Produces **aqueous** (non-pigmented layer) 2 layers: **pigmented** layer and **non-pigmented** layer Muscle for accommodation Important **blood vessel** that can rupture during trauma

Question 98

Malignant melanoma of eye

Answer 98

Most common malignant disease of **uvea** Slower growing than melanoma on the skin, but still can kill you

Question 99

Retina

Answer 99

Thin membrane that **covers entire posterior compartment**, contiguous with optic nerve Joins ciliary body **Processes** **light**, modulates, and sends to **lateral geniculate ganglion** 3 major cellular layers: **ganglion cell layer** (will form optic nerve)**, inter-nuclear layer** (electrical modulation system)**, photoreceptors**, retinal pigment epithelium (integrated with photoreceptors and keeps them alive)

Question 100

Macular degeneration

Answer 100

Causes **decrease in central vision** Fibrous tissue grows between retina, from choroid Doesn't cause complete blindness

Question 101

Optic nerve

Answer 101

At posterior part of eye **Tubular** structure containing numerous **axons** of ganglion cells and glial cells arranged in columns which are separated by fibrous sheaths

Question 102

Optic atrophy

Answer 102

Final common pathway of most optic disease