Bio 366- Exam 2 Physiology

Decompression Sickness

A condition resulting from nitrogen trapped in the body's tissues caused by coming up too quickly from a deep, prolonged dive. A symptom of decompression sickness is "the bends" or deep pain in the muscles and joints.

respiratory acidosis

A drop in blood pH due to hypoventilation (too little breathing) and a resulting accumulation of Co2, decrease in pH.

When food enters the stomach, 3 chemicals are released that trigger parietal cells to secrete hydrochloric acid. One of the chemicals is called histamine. The over-the-counter medicine, Pepcid® that Mr. Estrada reported was helpful is a histamine receptor antagonist, or H2 blocker. Why is it called an H2 blocker and how did it help with Mr. Estrada's hyperacidity issue?

A histamine-receptor blocker inhibits the binding of histamine and diminishes hydrogen generation and HCl secretion, thus decreasing acidity.

If a patient does have exercise-induced bronchoconstriction, what do you expect the results to be on a Forced Vital Capacity (FEV1/FVC) test immediately after strenuous exercise?

FEV1/FVC<80%

If a patient does NOT have exercise-induced bronchoconstriction, what do you expect the results to be on a Forced Vital Capacity (FEV1/FVC) test be immediately after strenuous exercise?

FEV1/FVC>80%

Prior to exercise (i.e., at rest), what do you expect a patient who is expected to have exercise induced asthma's results to be on a Forced Vital Capacity (FEV1/FVC) test?

FEV1/FVC>80%

Tests that screen for diabetes

Fasting Glucose/Blood Sugar Test: glucose present in bloodstream (>126 mg/dl=diabetes) Oral Glucose Tolerance Test: how/if body is processing glucose Hemoglobin A1c Test: blood glucose over past 3 months Urinary Glucose Evaluation Urinary Ketone Evaluation: body begins burning fat when it doesn't have glucose stores

Type of bacteria commonly known to cause ulcerations in the upper GI tract

Helicobacter pylori (H. pylori)

Which disease affects the large intestine?

IBS

You take a popular high altitude drug called Diamox (acetazolamide), which alters the excretion rate of bicarbonate by the kidneys. Would you want the drug to increase or decrease bicarbonate excretion to help compensate for the acid-base imbalance in the previous question? (remember bicarb equation)

Increase

Urinalysis Abnormalities Leukocytes: Nitrites: Urobilinogen: Protein: pH: Blood: Specific gravity: Ketone bodies: Bilirubin: Glucose:

Leukocytes: infection (UTI) Nitrites: bacterial infection (UTI) Urobilinogen: liver damage/abnormalities Protein: kidney damage pH: metabolic or respiratory Blood: kidney damage Specific gravity: multiple Ketone bodies: diabetes if really high Bilirubin: liver disease Glucose: diabetes

Normal Urinalysis Leukocytes: Nitrites: Urobilinogen: Protein: pH: Blood: Specific gravity: Ketone bodies: Bilirubin: Glucose:

Leukocytes: none Nitrites: none Urobilinogen: trace Protein: none pH: 4.6 to 8.0 Blood: none Specific gravity: 1.003-1.035 Ketone bodies: none/trace Bilirubin: none Glucose: none

Would blood gas concentrations increase or decrease... •On the top of Mount Everest? •Below sea level?

Mount Everest: decrease Below sea level: increase

Explain why Mr. Estrada's dyspepsia is triggered by food, but then begins to subside about 2-4 hours after he eats?

Mr. Estrada's dyspepsia is triggered by food because he has a gastric (stomach) ulcer. Before he eats, the cephalic phase prepares the stomach for eating, prompting the secretion of acidic gastric juices into his empty stomach before he even ingests food. This is very irritating to the ulcer because he has significantly less mucus present in that area to protect against the incredibly low stomach pH of 2. This would certainly cause a significant amount of pain as the acid interacts with the unprotected tissue of the ulcer. Once he eats and the food reaches his stomach, the stomach begins to churn and work really hard to mix all of the food and this movement can also be incredibly discomforting. Approximately 2-4 hours after eating, the stomach begins to empty as the chyme heads out of the stomach and into the duodenum of the small intestine. He experiences relief during this time interval (the intestinal phase) because as food leaves the stomach, gastric secretions are inhibited and it stops churning. It might be helpful to direct him to avoid certain foods that are spicy or contain high levels of fat and to try eating smaller meals. This will help to prevent his stomach from having to work super hard and hopefully reduce the discomfort that accompanies meals until he finishes treatment.

Peptic ulcers can be caused by excessive use of _________.

NSAIDS

Using the atmospheric pressure at 33 feet below sea level, calculate the partial pressure of O2, N2 and CO2 in mmHg.

O2: 0.20*1520 mmHg = 304 mmHg N2: 0.80*1520 mmHg = 1216 mmHg CO2: 0.0004*1520 mmHg = 0.608 mmHg

You are going to visit grandma, who lives on top of a mountain. The atmospheric pressure at grandma's is 400 mmHg. Calculate the partial pressure of O2, N2 and CO2 in mmHg.

O2: 0.20*400 mmHg = 80 mmHg N2: 0.80*400 mmHg = 320 mmHg CO2: 0.0004*400 mmHg = 0.16 mmHg

Partial pressures of gases in air

O2: 20% N2: 80% CO2: 0.04%

Dalton's Law for Air

Pair = PN2 + PO2 + PCO2

You decide not to play basketball regardless because of this low oxygen pressure, which is making you feel sick. The main reason you feel sick is because you have begun to breath quickly to compensate for the low oxygen, but in turn, you feel sick because you've now altered your acid-base balance. What condition would you be in? (remember bicarb equation)

Respiratory Alkalosis

In addition, the H. pylori also disrupts the normal buffering effect that occurs in the duodenum. Explain this buffering effect and how it would protect the duodenum?

The duodenum secretes bicarbonate-rich juice into the duodenum and duodenal submucosal glands, and a mucus that is also rich in bicarbonate. This offers protection by neutralizing the acidic chyme and coating the duodenum in alkaline mucus.

Mr. Estrada is curious what bacteria have to with an ulcer. Dr. Moser tells him that the H. pylori increases stomach acid secretion and breaks down the lining of your stomach and duodenum. Why would damage to the mucosa layer allow other layers to be damaged?

The simple columnar epithelium contains mucus cells which produce an alkaline mucus that protects against the acidic gastric juices. If destroyed, the underlying layers are unprotected against the acid from the stomach.

Measure following on graph: Tidal volume (TV) Vital capacity (VC) Inspiratory reserve volume (IRV) Expiratory reserve volume (ERV) Residual volume (RV) Total lung capacity (TLC)

Tidal volume (TV) = 400 mL Vital capacity (VC) = 3000 mL Inspiratory reserve volume (IRV) = 2000 mL Expiratory reserve volume (ERV) = 600 mL Residual volume (RV) = 1200 mL Total lung capacity (TLC) = 4200 mL

For the following measurements, think through whether they would increase, decrease, or remain the same during exercise: Tidal volume (TV) Vital capacity (VC) Inspiratory reserve volume (IRV) Reserve volume (RV) Respiratory rate

Tidal volume (TV): increase Vital capacity (VC): stay the same Inspiratory reserve volume (IRV): decrease Reserve volume (RV): stay the same Respiratory Rate: increase

Tidal volume for patients with obstructive and restrictive disorders

Within normal range with exception of severe conditions

Methylene blue is a pro-drug that is used to reduce methemoglobin to hemoglobin. a.) Why didn't the patient respond to oxygen therapy before methylene blue was administered? b.) Why did the patient respond to oxygen therapy after methylene blue was administered?

a) The patient didn't respond to oxygen therapy before methylene blue was administered because she didn't have sufficient while hemoglobin was available, it wasn't in the form for oxygen to bind. This leads to an inability for O2 to bind and be transported in the blood even when it is present in excess. b) After treatment with methylene blue, methemoglobin was able to be converted to hemoglobin which is able to bind to oxygen. This allows it to be present in the blood and carried throughout the body.

Procedure in which a small piece of tissue is removed to then be analyzed in a laboratory

biopsy

Which conditions can decrease serum hemoglobin levels?

cancer, kidney failure, acute/chronic bleeding

A patient with GERD, has an ineffective _______ sphincter.

cardiac

If they are big enough, gallstones would block the _______.

cystic duct

Atmospheric pressure ________ with elevation. Gas concentration is ____ dense at higher altitudes.

decreases; less

Small perforations in the large intestine might result from _________.

diverticulitis

Ulcerations in the lining of the duodenum

duodenal ulcer

Abdominal discomfort

dyspepsia

Procedure in which a camera is inserted through the esophagus to examine an aspect of the GI tract

endoscopy

Ulcerations in the lining of the stomach

gastric ulcer

Malignant tumors affecting the esophagus, stomach, small intestine, large intestine, biliary system, pancreas, rectum, or anus

gastrointestinal cancer

Obstructive diseases

increase airway resistance •Asthma •Bronchitis •COPD •Cystic fibrosis •Emphysema Breathing through a straw

Atmospheric pressure ________ below sea level. When diving below sea level, concentration ___________ for all gases.

increases; increases

Restrictive diseases

inhibit inhalation limited chest expansion (distensibility) •Kyphosis •Obesity •Pulmonary fibrosis •Tuberculosis Hunched over

Gastric bypass surgery connects the stomach to the ________.

jejunum

What is the name of the sugar that is not digested and must be fermented by bacteria in the large intestine when an enzyme is deficient?

lactose

In some patients, a sulfonamide antibiotic can cause low hemoglobin. Based on this knowledge and the effects of methylene blue from the question before, what is the probable diagnosis for the patient?

methemoglobinemia

Relative to pre-disease, a patient with a/n _________ disease would show a decrease in a forced vital capacity test (FEV1/FVC) (i.e., an increase in time to exhale in our straw demos), while a patient while a patient with a/n ___________ disease would show a decrease in vital capacity (VC).

obstructive ; restrictive

Ulcerations in the lining of the stomach or first portion of small intestine

peptic ulcer

Mucosal ______ which come into contact with toxins in feces can develop into tumors.

polyps

You won a trip to Costa Rica for spring break! You sign up for diving lessons and find out they include math! Your dive instructor asks you to calculate the total atmospheric pressure while 33 feet under water.

pressure= 1520 mmHg and 2 atm Pressure increases by 1 atm (760 mmHg) for every 33 feet descended ~ in addition to the initial 1 atm (760 mmHg) above the water

Gestational diabetes

the body is less responsive to insulin •Spares glucose for fetus

Hemorrhoids are swollen and inflamed ________ around the anus.

veins

People with celiac disease have damaged ______.

villi

Insulin

•(Blood glucose (BG) - target BG) / correction factor = # of units of insulin for current BG •(142 mg/dl - 120 mg/dl) / 24 md/dl per unit = 0.9 units of insulin for current BG •Carbohydrates in meal / Insulin:carbohydrate ratio = # of units of insulin for meal •68 g / (1 unit/9 g) = 7.6 units of insulin for meal •Insulin correction factor + insulin needed for meal = total insulin administered •Total insulin needed = 0.9 units + 7.6 units = 8.5 units •Round to the nearest half unit

Gas exchange is driven by

•Dalton's law (Ptotal = P1 + P2 + P3 +........Pn) •Henry's law (C = KH x P)

FEV1/FVC

•FEV1 = forced expiratory volume in 1 sec •How much air can you expel in 1 sec? •FVC = forced vital capacity •Total volume or air expelled

Nitrogen Narcosis

•Increased PN2 increases the N2 blood gas concentration •Excess N2 diffuses into tissues •Same effect as a few martinis

Atmospheric pressure increase below sea level

•Increases 1 atm per 33-ft descent •1 atm = 760 mmHg •Don't forget the starting pressure at sea level

Normal blood glucose

70-100 mg/dL •1.0 dL = 0.1 L •Maintained primarily by insulin and glucagon

Pre-diabetes: fasting and glucose tolerance test

100-125 mg/dL 140-199 mg/dL

Diabetes: fasting and glucose tolerance test

>125 mg/dL ≥200 mg/dL

respiratory alkalosis

Arise in blood pH due to hyperventilation (excessive breathing) and a resulting decrease in CO2, increase in pH.

Tests that screen for Type 2 diabetes

Blood Pressure: High BP is a risk factor Lipid Panel/Cholesterol Test: High for either is a risk factor

Ventilation is driven by

Boyle's law (P1V1 = P2V2) •Pressure is inversely related to volume

Tests that screen for Type 1 diabetes

C-peptide Test: 1:1 ratio with insulin - is insulin being produced?

bicarbonate equation

CO2 +H2O ↔ H2CO3 ↔H+ + HCO3-