Section 2: Head, Eyes, Ears & Urogenital Systems

Blood-Brain Barrier (BBB) Function

Tight junctions allow oxygen and glucose through while blocking blood cells, antibodies, and most bacteria.

Septic Meningitis Features

Bacterial, life-threatening, and bacteria can be cultured directly from CSF.

Aseptic Meningitis Features

Viral, usually milder, and no bacteria grow in CSF culture.

Listeriosis Cause & Trait

Caused by Listeria monocytogenes, which can grow at refrigeration temperatures (cold-tolerant).

Listeriosis Pregnant Risk

Crosses the placenta in pregnant women, potentially causing miscarriage or stillbirth.

Prion Definition

An infectious, misfolded protein that destroys brain tissue.

Prion Resistance

Extremely resistant to heat, radiation, and standard hospital disinfectants.

Conjunctivitis Features

Inflammation of the outer lining over the eye; produces pus if bacterial.

Keratitis Features

Painful inflammation of the cornea that directly threatens vision.

Trachoma Blindness Mechanism

Repeated Chlamydia infections scar the inner eyelid, turning eyelashes inward to scratch the cornea.

Why children get Otitis Media

Their Eustachian tubes are shorter, narrower, and more horizontal, preventing fluid drainage.

UPEC Evasion 1: Attachment

Uses specialization pili to anchor firmly to bladder walls.

UPEC Evasion 2: Protection

Forms intracellular biofilms inside bladder cells to hide from treatments.

UPEC Evasion 3: Defense

Uses filamentation (growing long) to prevent white blood cells from eating it.

Lactobacillus Vaginal Role

Ferments glycogen into lactic acid to maintain a low, protective pH.

Pelvic Inflammatory Disease (PID) Definition

Infection spreading up into the fallopian tubes.

Pelvic Inflammatory Disease (PID) Risks

Causes scarring that leads to ectopic pregnancy (egg stuck in tube) or infertility.

Chlamydia Elementary Body (EB)

The infectious, non-replicating form that survives outside host cells.

Chlamydia Reticulate Body (RB)

The non-infectious, actively replicating form inside host cells.

Syphilis Primary Stage

Painless sore (chancre) at the site of infection.

Syphilis Secondary Stage

Widespread skin rash and flu-like symptoms.

Syphilis Tertiary Stage

Severe tissue destruction (gummas), cardiovascular issues, and nerve damage.

Why losing CD4 T cells is fatal

CD4 T cells are the "generals" that signal B cells to make antibodies and Killer T cells to attack.

HIV Clinical Latency

Virus is actively replicating and destroying cells every day, even if the host feels healthy.

True Latency (e.g., Herpes)

Virus is completely dormant and non-replicating inside cells.