Pathophysiology Daily Quizzes for Exam 3

High output heart failure occurs when the blood volume is normal and the heart is beating normally. How can heart failure occur? Remember that heart failure means the heart is not pumping enough blood to meet the metabolic needs of the body. Conditions that raise that metabolic demand can cause this, such as hyperthyroidism, fever, and in a related fashion, septicemia.
Shock :

Lung Review: (stolen from A&P I)
The exchange of gases between the blood and the tissues is called what?   internal respiration
What is another term for ventilation?   Breathing -  moving air in and out of the lungs
Why (chemically speaking) do we need oxygen?  Remember that it accepts electrons at the end of the electron transport chain, and also picks up two hydrogen ions to make water.
Why do we sound funny when we have a cold? In addition to warming, filtering and moistening the air we breathe, our paranasal sinuses and nasal cavity act as resonating chambers that give our voice its characteristic sound.
We see pseudostratified ciliated columnar epithelium in the nasopharynx and trachea, but not in the oropharynx or laryngopharynx. Why not? The last two areas are also part of the digestive system, so rough foods (like charbroiled hamburger) may scratch these areas . Stratified squamous epithelium does a better job of protecting the under lying tissues against abrasion in these areas.
Which of the cartilages that make up the larynx could you use to tell if a decomposed body was male or female? In the male the thyroid cartilage forms a 90 degree angle, making the “Adam’s apple” more pronounced and making the vocal cords longer (and the voice deeper).
What is the function of the "false vocal cords"?  Along with the epiglottis, they prevent food or substances other than air, from entering the trachea while we are swallowing.
Why does the trachea have “C” shaped rings of  cartilage? If their function is to hold the trachea open, wouldn’t “O” shaped rings be better?
The open part of the C faces posteriorly, toward the esophagus. When a bolus of food comes down the esophagus, the esophagus can temporarily bulge into the trachea to let the food pass.
What is the carina?  This is the ridge on the inside of the bottom of the trachea where the right and left primary bronchi branch off. It has a very sensitive cough reflex.
You enjoy being with your best friend because he's so funny. Unfortunately, he made you laugh while you had a small, hard candy in your mouth and you inhaled it! Where would it probably end up?  It would most likely end up in the right lung, because the right primary bronchus is shorter, wider and more vertical than the left, and a falling object would tend to take the path of least resistance.
In lab, how do you tell the difference between a small bronchus and bronchiole?  Bronchi are held open by rings of cartilage. Bronchioles do not have these rings, and so can constrict and block off air flow, as happens in asthma.
Oh no! I’m in the lab and I have an asthma attack. I have neurotransmitters available from the parasympathetic and sympathetic nervous system. Which should I take?   I should definitely use the norepinephrine or epinephrine from the sympathetic nervous system, because they will dilate bronchioles. If I used acetylcholine, it could cause my bronchioles to constrict even more.
What are the membranes surrounding the lungs?   The visceral pleura is closest to the lung itself, and the parietal pleura lines the thoracic cavity wall.


How do the right and left lung differ and why? The right lung has three lobes and two fissures; the left lung has two lobes and one fissure. The right lung is shorter because of the space taken up by the liver; the left lung is long and narrow, and contains the cardiac notch (where the heart goes) and the lingula, a little tongue-like flap of tissue.
What three types of cells would you find in an alveoli, and what do they do? The majority of the cells in the alveoli are the simple squamous epithelial cells (type I) that make up part of the respiratory membrane across which gas exchange takes place. We also find Type II cells that produce surfactant to lower the surface tension of the water in the lungs, and macrophages called "dust cells" that  consume foreign particles and microorganisms that reach the alveoli.
What is respiratory distress syndrome, and what can be done to help? This is caused by a lack of surfactant production in a premature infant; they use up all their energy trying to expand their lungs and exhaust themselves to the point of death. We used to administer high amounts of oxygen to these babies, but that caused other problems. Now we can give the surfactant until the baby makes its own.
Describe the alveolar-capillary or respiratory membrane. How is it suited to diffusion? It is made up of two simple squamous cells, one from the alveolus and one from the capillary, and the basement membrane between them. This is the thinnest membrane we can make and still keep the air in the lungs and the blood in the vessels.
Describe the muscles involved in inspiration. Which one is the most important? We normally use the external intercostal muscles and the diaphragm. By far, contracting the diaphragm draws in the most air. When we want to take a deeper breath, we can also use the sternocleidomastoids, scalenes and pectoralis minor muscles.
How does expiration occur? What additional muscles are involved in forced inhalation and in forced exhalation? Expiration is normally a passive process - we just relax the muscles of inspiration. For a forceful expiration we can also contract the internal intercostals and the abdominal muscles.
Be able to calculate minute volume of respiration. This is the amount of air a person moves in and out in one minute. Simply multiple the tidal volume times the number of breaths per minute.
What is the medullary rhythmicity center, and what does it controll? How is it influenced by the pneumotaxic area of the pons? This is the area of the brain that sets the normal pattern of breathing. The pneumotaxic area of the pons receives information from stretch receptors in the lungs, and will over-ride and shut off inspiration before the lungs overinflate.
What influences the central chemoreceptors, and how do they respond? The peripheral chemoreceptors?
The central chemoreceptors look for changes in carbon dioxide and pH (which are tied together). When pH drops, we breath faster to eliminate CO2, and when pH rises we breath more slowly.  The peripheral chemoreceptors respond to oxygen levels, but don't respond until the oxygen level is very low.
What is hyperventilation and how does it affect blood pH? Why? This is breathing too fast. We blow off too much carbon dioxide, and our pH rises. This can cause changes in the brain that can cause fainting or dizziness.
What is the normal atmospheric pressure at sea level? What do we mean by a partial pressure?
760 mmHg. The partial pressure is the part of the total pressure that is due to a particular gas, such as oxygen.
How does the partial pressure of a gas influence its diffusion? Gases diffuse from areas of high partial pressure to areas of low partial pressue.
How is oxygen transported in the blood (be specific). Bound to the iron in the heme portion of hemoglobin.
Why is carbon monoxide dangerous? Because it binds to the same place as oxygen, but more tightly, so it decreases the ability of the blood to transport oxygen.
What three ways does the blood transport carbon dioxide? How is MOST of the carbon dioxide transported? Dissolved in plasma (only a little), bound to the globin part of hemoglobin (23%), but most (70%) of the carbon dioxide is transported as bicarbonate ion.

When an area of the lung becomes hypoxic, the blood vessels supplying that area : constrict, so that blood can be sent to a part of the lung where there is more oxygen. This is the opposite of what happens elsewhere in the body.
The two major factors that reduce pulmonary function are: inadequate blood flow to the lungs (hypoperfusion) and inadequate air flow to the alveoli (hypoventilation).
Why are lung infections common in hospitals? Factors that reduce airflow also reduce the clearance of particles from the airways and predispose to infection; factors like: positioning, constrictive bandages, coma, and central nervous system depression.
What are the typical signs and symptoms associated with respiratory disorders? Cough, dyspnea and cyanosis.
What would cause a person to cough? This is usually due to mucus or fluids accumulating in the lower respiratory tract due to inhalation of irritating substances, lung tumors, and pulmonary edema.
Does a lack of cyanosis mean that an individual is okay? No, in adults cyanosis is not apparent until severe hypoxemia is present.
Does cyanosis always mean a person is hypoxic? Not necessarily. Individuals with polycythemia may show signs of cyanosis with adequate oxygenation.
What is respiratory failure? It is the inability of the lungs to adequately oxygenate the blood and/or to clear it of carbon dioxide.
When not enough oxygen gets into the alveoli, what do the capillaries of the lung do? They constrict, which can increase the blood pressure in the lungs, cause pulmonary edema, and heart failure.
Lung pathologies tend to affect which side of the heart? The right side. The right side of the heart can be thought of as the organ that comes just before the lungs as far as circulation is concerned. (The left heart comes after the lungs.)
What characterizes airway obstruction? reduced ventilation caused by small airway diameter, accumulation of secretions or loss of pulmonary elastic recoil.
What is the principal feature of ARDS? Acute pulmonary edema from capillary damage, which can arise from many etiologies.

Kidney:
Urine is concentrated by: The action of the loop of Henle and occurs in the distal convoluted tubules and collecting ducts.
A dilute urine is formed: when ADH secretion is not released and water is not reabsorbed from the distal convoluted tubules and collecting ducts.
Where does filtration occur? Only in the renal corpuscle - through the filtration membranes of the glomerulus.
What force causes fluid to leave the glomerular capillaries? The hydrostatic or perfusion pressure of the blood.
What two forces oppose filtration? The osmotic or oncotic pressure of the blood and the hydrostatic force of the filtrate in Bowman's capsule.
When will the renin-angiotensin system be activated? When the blood pressure in the afferent arteriole decreases.
When the glomerular filtration rate decreases, the plasma creatinine concentration will: increase.
Trace the flow of filtrate through the kidneys by putting the following in the correct order: collecting duct, Bowman's capsule, distal convoluted tubule, loop of Henle, proximal convoluted tubule. Bowman's capsule, proximal convoluted tubule, loop of Henle, distal convoluted tubule, collecting duct.
You see protein in a urine sample. What is the most likely location of the problem (be specific)? The glomerulus- this is where the urine is filtered, and the filtration membrane usually holds these proteins in the blood. If there is protein in the urine, it indicates a breakdown in the filtration membrane.
The patient has difficulty concentrating urine and retaining sodium. Where is the problem? The part of the kidney most responsible for this would be the distal convoluted tubules and collecting ducts, so this problem is affecting the tubules.
In general, when the kidneys are not functioning, what would you expect to happen in the rest of the body? Hypertension, anemia, edema, electrolyte imbalance, acidosis. Can you figure out why these conditions occur?
Your patient is experiencing an acute onset of frequency, dysuria, groin pain, fever and chills. You suspect either bacterial cystitis or acute pyelonephritis. What would you look for in a urine sample that could indicate where the problem was? Look for white cell casts - these are white cells that have been pushed together to form an impression of the walls of the tubules - indicating the infection is in the kidney itself - pyelonephritis.
Which gender is more likely to experience urinary bladder infections? Why? Females due to the short length of the urethra - it is relatively easy for bacteria, especially those from the intestinal tract, to travel that distance into the bladder.
When would we see an increase in the incidence of bladder infections in the other gender? In males the incidence goes up after the age of 40 when enlargement of the prostate gland can cause retention of urine in the bladder.
The most common type of renal stone is made of : calcium phosphate.
An example of a type III hypersensitivity affecting the kidney would be: acute glomerulonephritis following a streptococcal infection. The antigen-antibody complexes are deposited in the walls of the glomerulus, which is then damaged through the activation of complement and frustrated phagocytosis by neutrophils.
An example of a type II hypersensitivity affecting the kidney would be: Goodpasture syndrome where antibodies are formed against the basement membranes of the capillaries in the lung and glomerulus. Remember that this is a type of RPGN and is most common in men 20 -30 years of age.
The nephrotic syndrome is characterized by: proteinuria of greater than 3.5 grams/day.
Bone fractures may be seen with chronic renal failure because: The kidney activates vitamin D, which promotes calcium absorption. When the kidney fails, it is unable to activate vitamin D, so less calcium is absorbed from the intestines, and bones can become fragile.
Blood in the urine appears a smoky brown color. Where is the blood coming from? Probably from the glomerulus. The long exposure to an acidic urine causes the color change. Bleeding in the lower urinary tract is usually pink or red.