a&p2 final (old content)

What are antigens and where are they found?

Cell surface proteins (on RBCs) used to distinguish self vs non-self

What is the function of antibodies?

Bind specific antigens and mark them for destruction

What determines ABO blood type?

Presence/absence of A and B antigens on RBC membranes.

What determines Rh status?

Presence of antigen D → Rh+

What is agglutination?

Antibodies cross-link RBCs → clumping.

Why can mismatched transfusions be fatal?

Cause hemolytic transfusion reactions.

Why is O- the universal donor?

No A, B, or Rh antigens.

Why is AB+ the universal recipient?

Has all antigens → no antibody reaction.

Why is the first Rh-mismatched pregnancy usually safe?

Mother hasn’t developed anti-D antibodies yet

What happens in later pregnancies?

Maternal antibodies attack fetal RBCs → hemolytic anemia.

How is Rh incompatibility prevented?

RhoGAM at ~28 weeks prevents antibody formation

What are the four chambers of the heart?

Right/left atria and right/left ventricles.

Function of atria

receive blood

Function of ventricles

pump blood out

What separates the chambers?

Interatrial and interventricular septa

Why is left ventricle thicker?

Pumps blood to the rest of the body

What is the function of valves?

Ensure one-way blood flow

What are the AV valves (names)?

tricuspid (right) and mitral (left)

What are the semilunar valves (names)?

Pulmonary and aortic

What causes valves to close?

Backflow of blood

Function of papillary muscles?

Contract to stabilize AV valves

Function of chordae tendineae?

Prevent valve prolapse into atria

What is the SA node?

Primary pacemaker in right atrium

Why is AV node delay important?

Allows ventricular filling

Conduction pathway

SA → atria → AV → bundle of His → bundle branches → Purkinje fibers

P wave represents?

Atrial depolarization

QRS complex?

Ventricular depolarization

T wave?

Ventricular repolarization

Key features of innate immunity

Nonspecific, no memory, rapid response

Key features of adaptive immunity

Specific, memory, improves with exposure

Examples of innate defenses

Skin, phagocytes, inflammation, fever

Cells of adaptive immunity?

B cells, T cells, plasma cells, memory cells

What happens during anaphylaxis?

Bronchoconstriction + vasodilation → shock

Treatment for anaphylaxis

Epinephrine

Function of pharynx

Passageway for air and food

Function of larynx

Airway protection + voice production

Function of trachea

Conduct air; cartilage prevents collapse

Difference between visceral and parietal pleura?

Visceral: on lungs; Parietal: lines thoracic cavity

Why is pleural fluid important?

Reduces friction and maintains pressure gradient

What drives breathing?

Pressure differences

What happens during inspiration?

Lung volume increases, pressure decreases, air goes in

What happens during expiration?

Lung volume decreases, pressure increases, air goes out

What muscle is most important for breathing?

Diaphragm

What is compliance?

Ease of lung expansion

Role of surfactant

Prevent alveolar collapse

What nerve controls diaphragm?

Phrenic nerve (C3–C5)

Function of digestive system

Digestion, absorption, waste elimination

GI tract vs accessory organs

GI: continuous tube; Accessory: assist digestion

Functions of the stomach

Storage, mechanical + chemical digestion

What is chyme?

Semi-liquid food mixture

Regions of the small intestine

Duodenum, jejunum, ileum

Main function of the small intestine

Absorption

Function of villi

Increase surface area

Carbohydrates are absorbed as

Monosaccharides (glucose)

Protein digestion begin in the

Stomach

What is emulsification

Bile breaks fat into droplets

What are micelles?

Transport lipids to cells

What are chylomicrons?

Transport lipids via lymph

Function of liver

Detox, metabolism, bile production

Function of gallbladder

Stores bile

Kidney functions

Filter blood, regulate BP, pH, electrolytes

Parts of nephron

Renal corpuscle + tubule

Where does filtration occur?

Glomerulus

PCT function?

Reabsorption

Loop of Henle function?

Concentration gradient

DCT function?

Fine tuning

Path of urine

Nephron → collecting duct → ureter → bladder → urethra

What triggers urination?

Stretch receptors in bladder

What happens during urination?

Detrusor contracts, internal and external sphincters relax

What controls defecation?

Spinal reflex + voluntary control