Exam 3 copy

Question 2

Neural Innervation of the GI Tract:Enteric Nervous System (ENS)

Answer 2

• Intrinsic set of nerves (“brain of gut”)- Neurons extending from esophagus to anus- Plexuses: myenteric plexus (GI tract motility) and submucosal plexus (controlling secretions)

Question 3

Neural Innervation of the GI Tract:Autonomic Nervous System (ANS)

Answer 3

• Extrinsic set of nerves- Parasympathetic stimulation: increases secretion and activity by stimulating ENS.- Sympathetic stimulation: decreases secretions and activity by inhibiting ENS.

Question 4

Peritoneal Folds

Answer 4

Peritoneal Folds

Question 5

External and Internal Anatomy of the Stomach

Answer 5

External and Internal Anatomy of the Stomach

Question 6

Chemical Digestion in the Stomach:Salivary Amylase

Answer 6

Salivary amylase: - digestion continues until inactivated by acidic gastric juice

Question 7

Chemical Digestion in the Stomach: Lingual Lipase

Answer 7

Lingual lipase: - acidic gastric juice activates lingual lipase - digest triglycerides into fatty acids and diglycerides

Question 8

Chemical Digestion in the Stomach:HCl

Answer 8

HCl - Parietal cells secrete H+ and Cl- separately but net effect is HCl- Kills many microbes, denatures proteins

Question 9

Chemical Digestion in the Stomach:Pepsin

Answer 9

Pepsin - Secreted by chief cells - Secreted as inactive pepsinogen - Digests proteins

Question 10

Chemical Digestion in the Stomach:Gastric Lipase

Answer 10

Gastric Lipase - Splits triglycerides into fatty acids and monoglycerides

Question 11

Absorption in the Stomach

Answer 11

• Small amount of nutrient absorption- Some water, ions, short chain fatty acids, certain drugs (aspirin) and alcohol.

Question 12

Anatomy of the Small Intestine

Answer 12

Anatomy of the Small Intestine

Question 13

Metabollism

Answer 13

All chemical reactions occuring in the body.

Question 14

Catabolism

Answer 14

Catabolism = breaking down of complex molecules.

Catabolism is exergonic—it produces more energy than it consumes.

Question 15

Anabolism

Answer 15

Anabolism = combine simple molecules to create complex molecules

Anabolism is endergonic = consuming more energy than it produces

Question 16

Overview of Cellular Respiration

Answer 16

Overview of Cellular Respiration

Question 17

Glycolysis Reactions

Answer 17

Glycolysis Reactions

Question 18

The Krebs Cycle is also known as…

Answer 18

The Krebs Cycle is also known as the citric acid cycle

Question 19

Where does the Krebs cycle occur?

Answer 19

In the matrix of the mitochondria

Question 20

What is the Krebs cycle?

Answer 20

A series of REDOX reactions.

Question 21

What are the important processes and steps of the Krebs cycle?

Answer 21

• 2 decarboxylation reactions release CO₂
• Reduced coenzymes (NADH and FADH₂) are the most important outcome
• One molecule of ATP generated by substrate-level phosphorylation

Question 22

Glycogenesis and Glycogenolysis

Answer 22

Glycogenesis and Glycogenolysis

Question 23

Lipoproteins - How are they categorized and named?

Answer 23

Lipoprotiens are categorized and named according to density (ratio of lipids to proteins)

Question 24

Lipoproteins - Chylomicrons

Answer 24

• Forms in small intestine mucosal epithelial cells
• Transport dietary lipids to adipose tissue

Question 25

Lipoproteins - Very Low-Density Lipoproteins (VLDLs)

Answer 25

• Forms in hepatocytes
• Transport endogenous lipids to adipocytes

Question 26

Low-Density Lipoproteins (LDLs)

Answer 26

* "bad" cholesteral * **Carry 75% of total cholesterol in blood** * *Deliver to body cells for repair and synthesis* * Can deposit cholesterol in fatty plaques.

Question 27

High-Density Lipoproteins (HDLs)

Answer 27

* "good" cholesteral * **Remove excess cholesterol from body cells and blood** * *Deliver to liver for elimination*

Question 28

Lipid catabolism (lipolysis)

Answer 28

* Triglycerides split into glycerol and fatty acids * Must be done in muscle, liver, and adipose tissue to oxidise fatty acids * Enhanced by epinephrine and norepinephrine

Question 29

Lipid anabolism (lipogenesis)

Answer 29

* Liver cells and adipose cells can synthesize lipids from glucose or amino acids * Occurs when more calories are consumed than needed for ATP production.

Question 30

Heat and Energy Balance - Hypothalamic thermostat is...

Answer 30

* Located in the preoptic area * It is the heat-losing (cooling) center and heat-promoting (warming) center.

Question 31

What functions does the kidney perform?

Answer 31

* **Regulation of blood ionic concentration** * *(most important ions = Na⁺, K⁺, Ca²⁺, Cl^- and HPO4^2- [phosphate ions])* * **Regulation of blood pH** * *(via secretion of H+ into urine and conservation of HCO3- [bicarbonate ions], which are an important buffer of H+ in the blood. Normal blood pH is 7.4 +/- 0.2)* * **Regulation of blood volume** * (inc. BV = inc. in BP; kidneys inc. or dec. BV by conserving or eliminating water in the urine) * **Regulation of blood pressure** * *Also:* * Maintenance of blood osmolarity * Production of hormones (Calcitrol [the active form of vitamin D] and erythropoietin) * Regulation of blood glucose level * Excretion of wastes from metabolic reactions and foreign substances (drugs or toxins)

Question 32

Cortical Nephrons - Overview

Answer 32

* Cortical nephrons **comprise 80-85% of nephrons** * Renal corpuscle *located in outer portion of cortex* and ***short loops of Henle** extend only into outer region of medulla*

Question 33

Cortical Nephrons - Flow 

Answer 33

Cortical Nephrons - Flow 

Question 34

Juxtamedullary Nephrons - Overview

Answer 34

* Juxtamedullary nephrons **comprise the other _15_-20% of nephrons** * *Renal corpuscle is **deep in cortex*** and ***long loops of Henle** extend deep into medulla* * Receive blood from peritubular capillaries and vasa recta * Ascending limb has thick and thin regions * ***_Enable kidneys to secrete either very dilute or very concentrated urine._***

Question 35

Juxtamedullary Nephrons - Flow 

Answer 35

Juxtamedullary Nephrons - Flow 

Question 36

Tubular Reabsorption

Answer 36

Reabsorption is the return of most of the filtered water and many solutes to the bloodstream. * About 99% of filtered water is reabsorbed * Proximal convoluted tubule cells make largest contribution * Solutes are reabsorbed by both active and passive processes

Question 37

Tubular Secretion

Answer 37

Tubular secretion is the transfer of material from blood into tubular fluid. * Secretion of H⁺ helps control blood pH * Secretion helps eliminate substances from the body

Question 38

Summary of Filtration, Reabsorption and Secretion in the Nephron Collecting Duct 

Answer 38

Summary of Filtration, Reabsorption and Secretion in the Nephron Collecting Duct 

Question 39

Body Fluid Compartments 

Answer 39

Body Fluid Compartments 

Question 40

The body can gain water by... 

Answer 40

The body can gain water by: * Ingestion of liquids and moist foods (2300 mL/day) * Metabolic synthesis of water during cellular respiration (200 mL/day) 

Question 41

The body can lose water through... 

Answer 41

The body can lose water through: * Kidneys (1500 mL/day) * Evaporation from skin (600 mL/day) * Exhalation from Lungs (300 mL/day) * Feces (100 mL/day) 

Question 42

Intracellular Fluid (ICF) vs. Extracellular Fluid (ECF)

Answer 42

* ECF's most abundant cation is Na⁺, anion is Cl^- * ICF most abundant cation is K⁺, anions are proteins and phosphates (HPO₄^2-) * Na⁺/K⁺ pumps play a major role in keeping K⁺ high inside cells and Na⁺ high outside cells.

Question 43

Sodium (Na⁺)

Answer 43

* Most abundant ion in ECF * 90% of extracellular cations * Plays pivotal role in fluid and electrolyte balance because it accounts for almost half of the osmolarity of ECF * Level in blood is controlled by: * Aldosterone—increases renal absorption * ADH—if sodium is too low, ADH release stops * Atrial Natriuretic Peptide (ANP)—increases renal excretion

Question 44

Bicarbonate (HCO₃^-)

Answer 44

* 2nd most prevalent extracellular anion * Concentration increases in blood passing through systemic capillaries picking up carbon dioxide * Carbon dioxide combines with water to form carbonic acid which dissociates * HCO3- drops in pulmonary capillaries when carbon dioxide is exhaled * Chloride shift helps maintain correct balance of anions in ECF and ICF * Kidneys are main regulators of blood HCO3- * Can form and release HCO3- when blood level is low or excrete excess to the the urine if blood level is high.

Question 45

Calcium (Ca2+)

Answer 45

**Most abundant mineral in body:** * 98% of calcium in adults is in skeleton and teeth * In body fluids, main an extracellular cation * Plays important roles in blood clotting, neurotransmitter release, muscle tone, and excitability of nervous and muscle tissue. **Concentration is regulated by parathyroid hormone:** * Stimulates osteoclasts to release calcium from bone—resorption * Also enhances reabsorption from glomerular filtrate * Increases production of calcitrol to increase absorption from GI tract

Question 46

Acid-Base Balance

Answer 46

* Keeping H+ concentration (pH) of body fluids at an appropriate level is a major homeostatic challenge. * 3D shape of proteins sensitive to pH * Diets with large amounts of proteins produce more acids than bases, which acidifies blood * Several mechanisms help maintain pH of arterial blood between 7.35 and 7.45 1. Buffer systems 2. Exhalation of CO2 3. Kidney excretion of H+

Question 47

Acid-Base Imbalances

Answer 47

The normal pH range of arterial blood is between 7.35 and 7.45 * ***Acidosis*** = blood pH below 7.35 (acidic) * ***Alkalosis*** = blood pH above 7.45 (basic)

Question 48

What are the major physiological effects of acid-base imbalances?

Answer 48

* **Acidosis**—results in depression of synaptic transmission in CNS * **Alkalosis**—results in overexcitability of CNS and peripheral nerves

Question 49

Respiratory Acidosis

Answer 49

Respiratory Acidosis: * Abnormally high PCO2 in systemic arterial blood * Cause is inadequate exhalation of CO2 * Any condition that decreases movement of CO2 out—emphysema, pulmonary edema, airway obstruction * Kidneys can help raise blood pH * Goal is to increase exhalation of CO2 - ventilation therapy

Question 50

Respiratory Alkalosis

Answer 50

Respiratory Alkalosis: * Abnormally low PCO2 in systemic arterial blood * Cause is hyperventilation due to oxygen deficiency from high altitude or pulmonary disease, stroke, or severe anxiety. * Renal compensation can help. * One simple treatment: breathe into a paper bag for a short time