Examine the ramifications of spleen removal.

Fred and Mary were working in the library and were asked to shift textbooks from one shelf to another. Fred asked Mary to hold out her hands so he could stack several books on her arms to carry multiple books at once. Fred noticed when he placed a textbook on Mary’s arms they would extend downward slightly for a moment and then return quickly to the original position, this happened with each additional textbook he added. Mary was surprised by this as she didn’t feel as if she was voluntarily restoring her arm position. When Fred placed a 5th very heavy textbook onto the stack in Mary’s arms her arms relaxed and all the text books fell to the floor, Mary insisted she didn’t drop the books purposefully but did feel the load was becoming too heavy for her to maintain her arm position.

1a) Which reflex is first being elicited as Fred adds each book to Mary’s arms to enable Mary to maintain her arm position? Provide a description of this neural reflex pathway, including the stimulus, receptor, neural pathway, effector and response. You may use a diagram if you wish.

1b) As Fred added the 5th textbook the increased load caused Mary’s arms to relax. Which sensory receptor was activated here and what is this detecting in the muscle? How does this result in Mary dropping the books?

1. One can increases their anaerobic threshold through aerobic endurance training. If aerobic athletes add strength training to their training routine, is this effective for increasing the anaerobic threshold?

Micro-computed tomography

1. How does this technique work and what does it measure?
2. What equipment is required for this technique?
3. How is the experiment/measurement performed?
4. What do the typical results look like? (you may want to include images here)  

An elderly relative or friend is worried about an upcoming hip replacement surgery. They aren't very internet savvy, nor do they trust "all that technology stuff." Plus, "this surgeon doesn't know about all my other health issues and medications like my doctor do." Describe the person you are helping through this situation: what specific topics would you discuss with them with regards to technology in medicine to ease their worries? How would you help them learn about the risks and benefits of the procedure, how the procedure is done, and how their recovery will be handled?

1. For Bone histomorphometry
   1. How does this technique work and what does it measure?
   2. What equipment is required for this technique?
   3. How is the experiment/measurement performed?
   4. What do the typical results look like? (you may want to include images here)  

for a blood volume of 5L and a cardiac output of 5L/ minute, what is the circulation time, that is to say, the average time required for a blood cell to pass completely around the systemic and pulmonary circuits?

a. same question above for a shrew?

b. what about an exercising shrew?

a person has a resting tidal volume of .5L, an expiratory reserve volume of 1 L, a residual volume of 1.5L and a vital capacity of 5L. About 150ml of the tidal volume represents dead space and 350 ml represents alveolar ventilation. at the end of a normal expiration, 2500 ml of alveolar gas remains in the alveoli and airways (the function residual capacity) In the subsequent inspiration, this volume is mixed with 359 ml of inspirer air to give a total of 2850 ml.

a. what proportion of the original alveolar gas remains in the alveoli after this one breath?

b. why is this value important?

c. what proportion is left on renewed after another breath?

16. Which of the following statements concerning alveoli would be correct? SELECT ALL THAT APPLY!!

a. Pulmonary surfactant of the alveoli is secreted by Type II alveolar cells.

b. When intra-alveolar pressure becomes greater than atmospheric pressure expiration will occur.

c. The walls of the alveoli are very thin and are surrounded by a network of capillaries so that air and blood are separated by only a very thin respiratory membrane.

d. Alveoli are the site of gas exchange in the lungs. e. The wall of the alveoli is composed primarily of simple squamous epithelium.

Special Senses:

What so special about the "Special Senses".

Why do we call General Senses general and Special Senses Special??

The mountain wind rattled the window of the small cabin as Drew sifted through the papers covering the kitchen table, looking for his physiology notes. Instead of his blue notebook, a pink sheet of paper from Mountain View Labs caught his eye. A closer look showed it to be his 73-year-old grandmother’s lab report from some recent blood tests. Mimi had protested all the way to the appointment and all the way home, but Drew had insisted that if he came home for Tanksgiving break, then she was going for the check-up that she had put of for far too long. Mimi had chronic kidney disease, and the doctors wanted her to start dialysis more than a year ago. Not surprisingly, his stubborn Kentucky-born-and-raised grandmother had refused. She was not a good candidate for home dialysis and the nearest dialysis clinic was an hour away. She didn’t drive much because of cataracts, and there was no one else to take her. Drew had immediately ofered to delay his junior year at the University of Kentucky to stay home and care for her. Mimi was adamantly opposed. “You will stay in school, Andrew Paul Killian! Te best way out of these mountains is college, and you’re not dropping out because of me.” Even after Drew discovered the county ofered senior citizens free transportation to medical appointments, she shook her head. “God the Almighty will take me home when He’s ready, dialysis or not.” Mimi had raised Drew since the age of three, and he knew when she made up her mind, no one on Earth could change it. Drew glanced at Mimi as she watched TV. He knew her kidney disease was advancing. He had noticed over the summer that she tired easily and her feet and ankles were badly swollen. She had always loved to debate politics with anyone who dared, but now she had trouble keeping track of conversation. Last week she only picked at her turkey and cranberry sauce, saying that she was too nauseated to eat much. She blamed it on the doctor scaring her about her high blood pressure at the appointment the day before, but Drew saw how baggy her clothes were and knew she hadn’t been eating much for quite some time. Drew started to scan the lab report, thinking his physiology class might help him understand the results. He had just enough time to note that Mimi’s blood urea nitrogen (BUN) was 208 mg/dL and creatinine was 15 mg/dL before she interrupted him. “Drew, there’s a Star Wars marathon starting!” She patted the sofa beside her. “Bring the rest of the snickerdoodle cookies and watch with me.” Drew found it hard to resist Star Wars or Mimi, so he laid the test results aside and spent the rest of the evening cheering for Luke and the Jedi. Te next morning Drew packed his car for the drive back to Lexington. He found his physiology notes, but Mimi had squirreled away the lab results. When he asked, Mimi fapped her hands at him. “Pffft, stop worrying! You just keep calling every morning to check on me like you have been. And Jimmy lives right over the hill. I’ll call him if I need anything.” Drew shook his head. Jimmy Seavers was at least a decade older than Mimi and relied on two canes to walk. He didn’t know how much help Jimmy would be, but Mimi was shooing him into the car to avoid any further protest. He hugged her long and hard, and reluctantly headed down the mountain road.

3. Describe the compensation provided by Mimi’s respiratory system. What effect will this have on her P_CO2?

Please answer all questions.

6. If tropomyosin is never moved off actin, what would be the result?

7. If you died, why would you develop rigor mortis?

8. All of the motor units in the fingers were very large (many muscle fibers per motor unit. How would this affect function?

9. If the calcium (Ca++) pumps did not function how would this affect muscles?

Going Under the Knife: A Case on Membrane Structure and Function

Twenty-year-old Kevin groaned and clutched his abdomen as he lay on the emergency room gurney. He had just been diagnosed with acute appendicitis and was waiting to be taken to the operating room (OR). Although he desperately wanted the pain to stop, Kevin was terrified of having general anesthesia. He hoped his fear wasn’t obvious to his older brother Cole, who was finishing medical school and thought he knew everything.

“Hang in there,” Cole said, for what seemed like the eighteenth time. “I’m sure they’ll get you upstairs as soon as they can. They don’t want that thing to burst.”

Kevin grunted. “I know…but does that anesthesia staff work all the time? How can I not wake up when someone’s slicing my gut open?”

Cole assumed a professorial air, and Kevin wished he’d kept his mouth shut. However, Cole didn’t get a chance to say anything before an aide arrived to take Kevin to the OR.

In the OR, someone placed a mask over Kevin’s face and when he blinked, he suddenly found himself in a hospital room with Cole waiting in a chair by the bed. “Welcome back to consciousness, little brother. How’s your abdomen feel?”

Kevin frowned. “Not as bad as it did. So it’s over? How did I get here already?”

“You’ve been out for a few hours,” Cole chuckled and then launched into the wonders of general anesthesia. “Certain neurons have to depolarize and undergo an action potential to maintain consciousness, but some anesthetics can hyperpolarize them and produce unconsciousness. The anesthetic binds to and opens a certain kind of potassium channel, which increases the “leak” current of potassium. However, it doesn’t affect voltage-gated potassium channels. This inhibits the neurons, and therefore you aren’t conscious of the surgeons performing the procedure. Amazing!”

Kevin groaned again, but not from the pain this time. Cole was undoubtedly right but he sounded like a textbook. “I’m just glad the stuff worked. Now when can I go home?”

Short answer questions

1. Kevin is conscious when certain neurons in his brain are active—they depolarize and undergo action potentials. Describe the process of depolarization of a neuron to threshold.

2. What does Cole mean when he says that anesthesia “inhibits the neurons?”

3. If the anesthesia opens more potassium leak channels, why are Kevin’s neurons less likely to produce action potentials?

4. Suppose Kevin’s pre-op blood work indicates that his extracellular potassium concentration is much higher than usual. This condition is known as hyperkalemia and must be corrected before he can undergo surgery. One of the dangers of hyperkalemia is that it makes neurons and muscle cells more excitable. Why does elevated extracellular potassium have this effect?