OMK Week 2 Block 1

Which cells are the first line of defense in the innate immune system?

Epithelial barriers, phagocytes, NK cells, complement proteins

Which immune response develops over days and involves lymphocytes?

Adaptive immunity

Which branch of adaptive immunity targets intracellular microbes?

Cell-mediated immunity

Which branch of adaptive immunity targets extracellular microbes?

Humoral immunity

Which cells produce antibodies?

B cells (plasma cells)

What is the main function of helper T cells?

Activate macrophages, B cells, and other immune cells via cytokines

What is the main function of cytotoxic T lymphocytes (CTLs)?

Kill infected or altered host cells

Which molecules present antigens to T cells?

MHC molecules

Which MHC class presents to CD8+ T cells?

MHC class I

Which MHC class presents to CD4+ T cells?

MHC class II

Which cytokine promotes Th1 differentiation?

IL-12

Which cytokine promotes Th2 differentiation?

IL-4

Which cytokine promotes Th17 differentiation?

IL-6, TGF-β

Which cytokine activates macrophages?

IFN-γ

Which cytokine is involved in allergy and eosinophil activation?

IL-5

Which antibody isotype is most effective at complement activation?

IgM

Which antibody isotype is most abundant in serum?

IgG

Which antibody isotype is most abundant in mucosal secretions?

IgA

Which antibody mediates allergic responses and parasite defense?

IgE

Which antibody isotype is produced first during a primary immune response?

IgM

What process leads to antibodies with higher binding affinity over time?

Affinity maturation

What process changes antibody isotype without altering antigen specificity?

Isotype class switching

Where does affinity maturation and isotype switching occur?

Germinal centers in secondary lymphoid organs

Which enzyme is critical for isotype switching?

AID (Activation-Induced cytidine Deaminase)

What is a polyclonal antibody response?

Response involving multiple B cell clones producing different antibodies

What is a monoclonal antibody response?

Response from one B cell clone producing identical antibodies

Which immune cells have Fcγ receptors for IgG?

Macrophages, neutrophils, NK cells, B cells

What happens when immune complexes bind Fc receptors on phagocytes?

Phagocytosis and destruction of the complex

What type of hypersensitivity reaction is mediated by IgE?

Type I hypersensitivity

Which antiviral is a guanosine analog requiring phosphorylation by viral thymidine kinase?

Acyclovir

Which antiviral is the oral prodrug of acyclovir?

Valacyclovir

Which antiviral is effective against HSV and VZV but not CMV?

Acyclovir

Which antiviral is used for ganciclovir-resistant CMV and does not require phosphorylation?

Foscarnet

Which antiviral is a pyrophosphate analog?

Foscarnet

Which antiviral is a guanosine analog effective for CMV retinitis?

Ganciclovir

Which oral prodrug of ganciclovir has better bioavailability?

Valganciclovir

Which drug is a DNA polymerase inhibitor used for HSV and VZV with less frequent dosing?

Famciclovir

Which antiviral is used topically for HSV lesions?

Penciclovir

Which PK parameter describes the theoretical volume that would contain the drug at the same concentration as in plasma?

Volume of distribution (Vd)

What is the equation for Vd?

Amount of drug in the body / plasma drug concentration

Which PK parameter measures the rate of drug elimination?

Clearance (CL)

What is the equation for clearance?

Rate of elimination / plasma concentration

What is the equation for half-life (t½)?

(0.693 × Vd) / CL

What is bioavailability (F)?

Fraction of administered drug reaching systemic circulation unchanged

What is the main determinant of oral drug bioavailability?

First-pass metabolism

Which phase of metabolism involves oxidation, reduction, and hydrolysis?

Phase I metabolism

Which enzyme family is responsible for most Phase I metabolism?

Cytochrome P450 enzymes

Which phase of metabolism involves conjugation to make drugs more water-soluble?

Phase II metabolism

Name three Phase II conjugation reactions.

Glucuronidation, acetylation, sulfation

Which G protein pathway activates adenylyl cyclase?

Gs

Which G protein pathway inhibits adenylyl cyclase?

Gi

Which G protein pathway activates phospholipase C?

Gq

Which second messenger is increased by Gs activation?

cAMP

Which second messengers are increased by Gq activation?

IP₃ and DAG

Which G protein signaling pathway increases intracellular calcium?

Gq via IP₃

Which receptor type uses intrinsic tyrosine kinase activity?

Receptor tyrosine kinases (RTKs)

Which receptor signaling pathway involves JAK/STAT?

Cytokine receptors without intrinsic kinase activity

What is the ligand for nicotinic acetylcholine receptors?

Acetylcholine (ACh)

What is the ligand for muscarinic acetylcholine receptors?

Acetylcholine (ACh)

Which sensory receptor detects vibration and is rapidly adapting?

Pacinian corpuscle

Which sensory receptor detects sustained pressure and skin stretch?

Ruffini endings

Which sensory receptor detects light touch and texture, and is slowly adapting?

Merkel cells

Which sensory receptor detects fine touch in hairless skin and is rapidly adapting?

Meissner’s corpuscles

Which pathway carries fine touch, vibration, and proprioception?

Dorsal column-medial lemniscus pathway

Which pathway carries pain and temperature sensation?

Spinothalamic tract

Where do first-order neurons of the dorsal column pathway synapse?

Nucleus gracilis and nucleus cuneatus in the medulla

Where do second-order neurons of the dorsal column pathway decussate?

Medial lemniscus in the medulla

Where do spinothalamic tract neurons decussate?

Within 1–2 segments in the anterior white commissure of the spinal cord

Which dermatome corresponds to the thumb?

C6

Which dermatome corresponds to the middle finger?

C7

Which dermatome corresponds to the little finger?

C8

Which dermatome corresponds to the nipple line?

T4

Which dermatome corresponds to the umbilicus?

T10

What is the neurotransmitter released by most sensory afferent neurons?

Glutamate

Which type of nerve fiber transmits sharp pain?

A-delta fibers

Which type of nerve fiber transmits dull, aching pain?

C fibers