A&p 2 exam 2

Where does gas, nutrient, and waste exchange occur?

Capillaries

As arteries move away from heart: / As veins move toward heart:

Arteries get smaller / Veins get larger

Distributing arteries vs. Conducting arteries

Distributing = Muscular arteries / Conducting = Elastic arteries

Systemic vs. Pulmonary blood oxygenation

Systemic arteries = Oxygenated (veins = deox) / Pulmonary arteries = Deoxygenated (veins = ox)

Function of vein valves & main blood reservoir

Valves prevent backflow / Main reservoir = Venous system (~65%)

Peripheral Resistance Relationships (Viscosity, Vessel Length, Radius)

• Higher Viscosity = Higher Resistance

• Longer Length =Higher Resistance

• Smaller Radius =Higher Resistance

Cardiac Output increases effect on Blood Pressure

Blood pressure increases

Effect of Hypertension & Hypotension on Net Filtration Pressure (NFP)

• Hypertension = Increases NFP (causes edema)

• Hypotension = Decreases NFP

Why is blood flow velocity slowest in capillaries?

To allow sufficient time for substance exchange between blood and tissue.

Capillary Fluid Balance (Filtration vs. Reabsorption)

More fluid is filtered at the arterial end than reabsorbed at the venous end.

Role of Atrial Natriuretic Peptide (ANP)

Promotes $Na+ and water excretion in kidneys =lowers blood pressure

What force drives fluid into lymphatic capillaries?

Interstitial fluid hydrostatic pressure

Drainage: Right Lymphatic Duct vs. Thoracic Duct

• Right Lymphatic Duct: Drains upper right body =empties into Right Subclavian Vein

• Thoracic Duct: Drains rest of body = empties into Left Subclavian Vein

Primary vs. Secondary Lymphoid Structures

• Primary: Red bone marrow, Thymus (site of production/maturation)

• Secondary: Lymph nodes, Spleen, Tonsils, MALT (site of immune response)

Lymphocyte Origin & Maturation Sites

• B cells: Originate & mature in Red Bone Marrow

• T cells: Originate in Red Bone Marrow, mature in Thymus

Thymus changes with age

Grows through infancy to puberty, then atrophies/involutes (replaces with fat).

What do Lymph Nodes filter vs. what does the Spleen filter?

Lymph nodes filter Lymph / Spleen filters Blood

Parasitic worm protection cell

Eosinophils

Function of Interferon

Cytokine released by virus-infected cells to protect neighboring cells from viral replication.

Pyrogens, Target organ, and Prostaglandin released

Target = Hypothalamus / Releases = Prostaglandin E2 ($PGE2) to induce fever.

CD4+ cells vs. CD8+ cells

• CD4+: Helper T cells ($TH)

• CD8+: Cytotoxic T cells ($TC)

MHC I vs. MHC II Molecules

• MHC Class I: Found on all nucleated cells (interacts with CD8+)

• MHC Class II: Found on APCs (interacts with CD4+)

Positive vs. Negative Selection of T cells

• Positive: Selects T cells that recognize self-MHC

• Negative: Eliminates T cells that attack self-antigens (prevents autoimmune disease)

• Activated B cells differentiate into...

• Plasma cells, which secrete antibodies

Cytotoxic T cell killing mechanism & Allergy Antibody

• Kills via Perforin and Granzymes

• Allergy antibody = IgE

Conducting Zone vs. Respiratory Zone

Conducting: Trachea/bronchi/terminal bronchioles (warms/cleans air, no gas exchange)

Respiratory: Alveoli & respiratory bronchioles (site of gas exchange)

Boyle's Law & Breathing Mechanics

• Inspiration: Volume go up then Intrapulmonary Pressure goes down (air enters)

• Expiration: Volume go down then Intrapulmonary Pressure goes up (air exits)

• Oxygen & CO2 Transport in Blood

O2: Mostly bound to Hemoglobin (~98.5%)CO2: Mostly as Bicarbonate ions (HCO3-) (~70%)

Factors causing Right Shift on Hb-O2 Curve (Bohr Effect)

increased temperature, increased P{CO2}, increased H+ (acidosis/low pH) then promotes O2 unloading to tissues.

Ventilation-Perfusion Coupling (Low Alveolar PO2})

Causes local arteriole vasoconstriction to divert blood flow to well-ventilated areas.

Main chemical stimulus for central chemoreceptors

Elevated P{CO2} (H+ in cerebrospinal fluid)

Stomach Parietal Cells vs. Chief Cells

• Parietal: Secretes HCl and Intrinsic Factor

• Chief: Secretes Pepsinogen

Bile origin/storage & function of CCK vs. Secretin

• Produced in liver, stored in gallbladder.

  • CCK: Stimulates gallbladder contraction & pancreatic enzymes

  • Secretin: Stimulates pancreatic bicarbonate release

• Lipid Digestion & Absorption Path

Emulsified by bile salts, digested by pancreatic lipase, packaged into chylomicrons, absorbed into lacteals.

• Cellular Respiration ATP Yield Sites

• Glycolysis: Cytoplasm (2 ATP, anaerobic)

• Krebs Cycle: Mitochondrial Matrix (2 ATP, aerobic)

• ETC: Inner Mitochondrial Membrane (~28–32 ATP, aerobic)

Hormones controlling Absorptive vs. Postabsorptive States

• Absorptive (Fed): Insulin

• Postabsorptive (Fasting): Glucagon

Path of Nephron Filtrate Flow

Glomerulus then Bowman's Capsule then PCT then Loop of Henle then DCT then Collecting Duct

• Renin-Angiotensin-Aldosterone System (RAAS) trigger & outcome

Low BP triggers Renin release then forms Angiotensin II then vasoconstriction + Aldosterone release then raises BP.

Aldosterone vs. ADH action on kidneys

• Aldosterone: Increases Na+(and water) reabsorption in DCT/collecting duct.

• ADH: Inserts aquaporins in collecting ducts to increase water reabsorption.

Countercurrent Multiplier (Loop of Henle) permeability

• Descending limb: Permeable to water, impermeable to NaCl.

• Ascending limb: Impermeable to water, actively pumps out NaCl.