Exam 2 Flashcards
Cortical Nephron
80-85% of nephrons, short loops of Henle, dilute urine, peritubular capillaries
Juxtamedullary Nephron
15-20% of nephrons, longer loop of Henle, concentrated urine, peritubular capillaries and vasa recta
Three Layers of Glomerular Filtration Membrane
- Fenestration of Glomerular Endothelium - keep in RBCs
- Basement membrane of Glomerulus - keep in plasma proteins
- Slit Membrane between pedicels of Podocyte - keep in medium-sized proteins needed for energy and muscle building
Aldosterone Function
Regulates potassium excretion and sodium/water reabsorption. More aldosterone, more sodium reabsorption
Juxtaglomerular Apparatus
Where the ascending loop contacts the afferent arteriole. Macula densa on nephron, granular (smooth muscle) cells on arteriole
Macula Densa
Senses amount of blood filtered out of glomerulus, high BV causes afferent arteriole to constrict, decrease renin production
Mesangial Cells
Cells with contractile properties that regulate GFR by modifying size of arteriole
Regulation of Hypotension by the Juxtaglomerular Apparatus
- Decreased sodium plasma, decreased BV
- Granular cells sense decrease and secrete renin
- Renin converts angiotensinogen to angiotensin 1 - slightly constricts blood vessel
- ACE converts angiotensin 1 to angiotensin 2 - slightly constrict vessel, stimulate adrenal cortex
- Adrenal cortex produces aldosterone - promotes sodium reabsorption and potassium secretion
4 Pressures Involved in Glomerular Filtration
Net Filtration Pressure = Glomerular Blood Hydrostatic Pressure - Capsular Hydrostatic Pressure - Blood Colloid Osmotic Pressure
Myogenic Renal Regulation
Macula Densa and Mesangial cells in afferent arterioles contract in response to high blood pressure
Tubuloglomerular Renal Regulation
Macula densa inhibits nitric oxide release (vasodilator) to constrict afferent arteriole
Neural Renal Regulation
Sympathetic tone causes AA constriction, reducing urine output and increasing blood availability for other organs
Hormonal Renal Regulation
Angiotensin II constriction to decrease GFR, ANP increases sodium excretion to reduce BP
Inulin
Fructose polymer that is neither reabsorbed nor secreted, used to measure GFR
Transport Maximum
Maximum level of glucose or protein needed to saturate transporters
Glycosuria
Presence of glucose in urine due to reaching transport maximum
Paracellular Reabsorption vs Transcellular Reabsorption
PR - Passive fluid leakage between cells
TR - active transport of solutes through cells
Diabetes Insipidus
Improper secretion of ADH, or responsiveness to ADH, resulting into too dilute urine
Angiotensin II
Contract AA, signal production of aldosterone in response to low BP
ADH
Increase facultative reabsorption of water to decrease osmolarity of body fluids - response to either low BV or high BO
Atrial Natriuretic Peptide (ANP)
Stimulated by stretching of atria, increases sodium excretion to reduce BV
Parathyroid Hormone
Increase calcium reabsorption
Acute Renal Failure
ability of kidneys to excrete wastes, regulate BV, pH, and electrolytes is impaired - detected by high blood creatine, result of tubule inflammation or kidney ischemia (lack of blood)
Glomerulonephritis
Inflammation of glomeruli due to autoimmune attack against glomerular capillary basement membrane - causes leakage of protein into urine, decrease colloid osmotic pressure, edema (fluid outside of blood)
Renal Insufficiency
Nephrons destroyed by disease - high salt and water retention, uremia (too much waste in blood), high hydrogen and potassium levels in plasma which can cause a coma
Polycystic Kidney Disease
Inherited disorder where sacs fill with fluid rather than being excreted - kidneys enlarge and lose function
Intracellular Fluid and Extracellular Fluid
ICF - cytosol
ECF - Interstitial fluid (80%) and blood plasma (20%)
3 Body Fluid Compartments
Plasma membrane - separate ICF and interstitium
Blood vessel walls - separate plasma and interstitium
Capillary Walls - allow exchange of water and solute between plasma and interstitium
2 types of Diabetes Insipidus
Central Diabetes Insipidus - caused by CNS inadequate secretion of ADH
Nephrogenic Diabetes Insipidus - inability of kidneys to respond to ADH, can be caused by genetic defect of channels or receptors
Formation and Release of ADH
ADH made in the hypothalamus, released from the posterior pituitary gland
ANP and BNP
ANP - atrium stretch increases salt excretion
BNP - ventricle stretch promotes diuresis (urine production), can help diagnose CHF
Functions of Electrolytes in Body Fluids
Control osmosis of water, maintain acid-base balance, carry electrical current (nervous system), serve as cofactors
Extracellular vs Intracellular Electrolytes
E - Sodium, chloride
I - Potassium, magnesium
Protein Buffer System Mechanisms
COOH group loses hydrogen or NH2 gains hydrogen
Hemoglobin Buffer System Mechanism
Oxyhemoglobin trades oxygen for hydrogen to become reduced hemoglobin, oxygen also binds with hydrogen to neutralize
Carbonic Acid-Bicarbonate Buffer System Mechanism
hydrogen and bicarbonate ion creates carbonic acid, carbonic acid can become hydrogen ion and bicarbonate ion
Phosphate Buffer System Mechanism
Hydroxide ion and Dihydrogen phosphate becomes water and monohydrogen phosphate. Monohydrogen phosphate and hydrogen ion become dihydrogen phosphate
Treat Respiratory Acidosis
excrete more Hydrogen ions and increase bicarbonate reabsorption, blood pH fixed but still high CO2
Treat Respiratory Alkalosis
decrease excretion of hydrogen ions and reabsorption of bicarbonate, blood pH fixed but CO2 still low
Treat Metabolic Acidosis
hyperventilate to lose CO2, blood pH will be normal but bicarbonate levels will still be low
Treat Metabolic Alkalosis
hypoventilation to retain CO2, blood pH will be normal but bicarbonate levels will still be high
Kidneys vs Lungs in pH balance
kidneys slower regulation but more long term effect, lungs faster regulation but less long term effect
Layers of the GI Tract
Mucosa - epithelium, lamina propria, muscularis mucosae
Submucosa
Muscularis - Circular and longitudinal muscle
*Submucosal plexus (nerves), Myenteric plexus (activate muscularis), Mesentery (fat anchor)
Hard Palate
Bony roof of the mouth
Soft Palate
Muscular roof of the mouth that allows movement of uvula
Uvula
Prevents swallowed food from entering nasal cavity
Lingual Frenulum
Limits posterior movement of the tongue
Gingivae
Cover tooth sockets and helps anchor teeth
Tongue Details
Skeletal muscle, mucous membrane, chewing swallowing speech, papillae and taste buds, salivary amylase and lipase
Pharynx
The throat, skeletal muscle to control the start of the swallowing reflex, mucous membrane to defend against infection
Esophagus Details
Collapsible, muscular tube posterior to trachea connective pharynx to stomach
Deglutition
Tongue shapes bolus and moves to back of the mouth, weight of food triggers swallowing reflex, uvula seals nasal cavity and epiglottis covers larynx
Stomach Cell Types and Functions
Surface Mucous Cell - secrete mucous to protect against acid
Mucous Neck Cell - secrete mucous and little absorption
Parietal Cell - secrete intrinsic factor for absorption of b12 and HCl to kill microbes, denature proteins, convert pepsinogen
Chief Cell - secrete pepsinogen which will break down proteins as pepsin
G Cell - secrete gastrin based on stretch receptors which will stimulate parietal and chief cells, increase motility, relax pyloric sphincter
HCl creation
Carbon dioxide and Water form Carbonic Acid with Carbonic Anhydrase
Bicarbonate and Cl antiporter, Cl facilitated diffusion
H-K ATPase, K facilitated diffusion
Phases of Digestion
Cephalic - senses of food to stimulate gastric secretion and motility (P and G stimulation
Gastric - stretch of stomach stimulates receptors, majority of gastric acid secretion
Intestinal Phase - inhibit gastric secretion and emptying due to secretin and CCK release
Digestive Enzymes
Salivary Amylase, Lingual Lipase, Pepsin and Gastric Lipase
Gastrin
Stretch of stomach promotes secretion of gastric juice, motility, relax pyloric sphincter
Secretin
High pH enters duodenum which stimulates pancreatic secretion and inhibits gastric secretion
CCK
Amino acids and fats enter duodenum which inhibits gastric emptying, stimulates bile secretion, induce satiety
Leptin
High fat content in body triggers regulation of fat storage and acts on hypothalamus to decrease apetite
Pancreas
Produce enzymes into duodenum to digest macros, Produce sodium bicarbonate to buffer stomach acid
*Stimulated by secretin
Function of Liver and Gallbladder
Store glycogen and fat, produce plasma proteins, detoxify blood, produce bile
Store, concentrate and release bile in response to fat entering duodenum (CCK)
Regulation of Bile and Pancreatic Secretion (steps)
CCK and secretin are released
CCK induces enzyme secretion and Secretin induces bicarbonate secretion
Bile created by liver, partially stimulated by secretin
CCK causes gallbladder contraction and relaxation of hepatopancreatic sphincter to release both bile and pancreatic juice
Small Intestine Functions
Mix, digest, absorb, propel chyme
Complete digestion of main macros, begins NA digestion
90% absorption
Mechanical Digestion in the Small Intestine
Segmentation - circular muscle mixes chyme with digestive juices and promotes absorption
Migrating Motility Complex (MMC) - peristalsis by circular and longitudinal muscle
Small Intestine Cells
Absorptive Cells
Goblet Cells - mucous
Enteroendocrine Cells - Secretin and CCK
Paneth cells - secrete lysozyme (bactericidal)
First Location of Nutrients after absorption
Liver determines how much to store and how much to give to rest of body
Carbohydrate Digestion Steps
Pancreatic Amylase turns starch into disaccharides
Brush Border Enzymes create monosaccharides
Secondary Active Transport with Sodium
Facilitated diffusion through monosaccharide carrier, Na-K ATPase
Protein Digestion Steps
Pancreatic Protease and Brush Border Enzymes turn protein in amino acids
Secondary Active Transport with Sodium
Facilitated Diffusion through Amino Acid Carrier, Na-K ATPase
Lipid Digestion Steps
Fat emulsified by bile salts
Pancreatic lipase turns triglyceride to monoglyceride and fatty acids
Those 3 form micelle and diffuse into cell
Fatty acids and monoglycerides recombine with protein to form chylomicron
Chylomicron enters lymphatic system through vesicles from Golgi Apparatus and exocytosis into Lacteal
Nucleic Acid Enzyme
Ribonuclease, Deoxyribonuclease, brush border enzymes
Hepatic Portal Vein
Brings amino acids and monosaccharides into the liver
Left Subclavian vein
Where lacteal/lymphatic system leads to after fat absorption
Enzyme that actively transports sodium and potassium
Na-K ATPase, involved in maintaining concentrations for water absorption
Colon Functions
Haustral churning (bulge packing feces), peristalsis (localized), mass peristalsis
Bacteria break down protein/amino acids, produce B vitamins
Some water, ion, vitamin absorption
GluT Transporters and Insulin
GluT allows glucose to pass into cell, Insulin increases GluT insertion, thus increasing glucose uptake and decreasing blood sugar
*Diabetes - insulin not responded to, high blood sugar
Glycogensis
Form glycogen from glucose
Glycogenolysis
Form glucose from glycogen
Gluconeogensis
Form glucose from proteins, triglyceride, lactic acid
Stimulated by cortisol, glucagon, thyroid hormones
4 types of lipoproteins
Chylomicron - dietary lipids to adipose tissue
VLDL - transport triglycerides from hepatocytes to adipocytes
LDL - carry 75% of total cholesterol, deliver to cells
HDL - remove excess cholesterol from cells and blood, transport to liver to be eliminated
Calorie
Heat needed to raise temp of 1 kg water by 1 degree Celsius
Protein and vitamin B12 connection
Foods high in protein typically possess B12
Omega 3 vs 6 Fatty Acid
Omega 3 is better
Saturated vs Unsaturated Fat
Saturated stacks and blocks blood vessels, unsaturated has kink so unlikely to form plaque
Electrolyte Function Review
Sodium - impulse, muscle, electrolyte balance
Chloride - osmotic pressure, HCl
Potassium - fluid volume, impulse, muscle, pH
Bicarbonate - buffer
Magnesium - enzyme cofactor, myocardium, CNS transmission, sodium pump operation
Calcium - bones and teeth, blood coagulation, neurotransmitter release, muscle tone, muscle and nerve excitability
Phosphate - buffer
