Physiology Problem Solving Homework
Summer 2015
Type in all your answers under each question using complete, grammatically correct sentences. Use Times 12 font and keep everything single spaced.
Please put effort into this, as it will be graded according to effort and the correctness of your answer with respect to physiological/scientific logic.
Minimum effort and input on your end will be graded with minimum effort and output on my end. For example, when an explanation is asked for, you need to back up your statements with ‘evidence’. A blank statement is not an explanation unless you back it up with logic or with data.
Since this is a word document, items will shift as you type. It is your job to keep the organization of this assignment clean by using margins and common sense. For example, don’t start a new headings at the bottom of a page, with the starting paragraph on the next page ( in editing, that is sometimes referred to as ‘orphaning’ or ‘decapitation’).
This is an individual effort. If a student copies work from another student, both students will receives a zero on this assignment.
Type your name, aligned to the right, at the bottom of each page.
Name : ______
First set of questions
What are electrolytes and what important role do they play in your body as discussed in our recent lectures. Limit your discussion to the major electrolytes seen and definitely include their importance in osmotic homeostasis. In addition, discuss their importance in the activity of neurons and why their specific concentrations are not equal inside/outside of cells. Your job is to provide a scientific logical and physiological summary of this important concept in one page.
The following Table gives 3 solutions. Only one solution is iso-osmotic with blood. The Osmolarity of blood is 300 milli-Osmolor. Explain which solution is iso-osmotic and back up your claim with data.
Solution 1 / Solution 2 / Solution 350 mM NaCl / 40 mM NaCl / 100 mM NaCl
25 mM KCl / 10 mM KCl / 5 mM KCl
25 mM MgCl2 / 20 mM CaCl2 / 5 mM CaCl2
100 mM Glucose / 120 mM Glucose / 25 mM Glucose
30 mM Fructose / 20 mM Fructose / 10 mM Fructose
(Note : make sure this table does not become cut in pieces when items in your document become shifted).
Explain how a solution, that is iso-osmotic with blood, may not always be iso-tonic. Think about the definition of osmosis and ‘tinker’ with the examples above.
What is the composition of normal physiological saline and explain why this is considered close to isotonic with blood.
Second set of Questions
Note : start this series of question at a new page and provide the answers to the question under each question. Once again, this is not a tweeting event or a texting event : complete sentences are required ! The questions are typed in italics. Your answers should NOT BE in italics. Some question are simple, some require you to look things up. DO not answer
A new Nurse intern has been working non-stop for 15 hrs in the ER. A patient was showing serious signs of dehydration. The Nurse took action without checking with the attending physician and administered 1 liter of sterile distilled water intravenously (I-V)
A few hours later , the patient was in worse condition. The resident physician drew blood from the patient and noticed that, after centrifugation, that the top plasma layer was pink instead of opaque white.
Questions :
1. From your previous lecture, what are the major fluid ‘compartments’ in the human body and how much fluid is in each compartment.
Your answer :
2. How much total blood does the average person have ? What is hematocrit and what is plasma ? How much % of blood is plasma and how much is that for a typical person ? What are the normal levels for hematocrit ?
Your answer :
3. The osmolority of blood is actually the osmolarity of the liquid in blood (=plasma). If you know that plasma Osmolarity is 300 milliOsmolar, and the Nurse added 1 Liter of distilled water to the blood, what would the osmolarity of the plasma be after the infusion ? Show your reasoning or calculations .( assume the 1 Liter added stays within the blood circulation)(hint: you need to take into account your answer from the questions above2).
Your answer :
4. If you can’t make the calculations, you still should be able to make a logical physiological deduction and explain why the plasma of the patient turned pinkish ? This example is often used in textbooks to illustrate aspects of osmosis. What do we call what happened in this specific condition and why ?
Your answer :
Third set of Questions
In a one page ( or more), explain what Hypernatremia is ! You need to discuss signs and symptoms , possible pathophysiology at cellular level and organ level, and treatment. (you can look this up easily)!
Finally , explain the things that would happen to brain tissue if there is a sudden dramatic (acute) condition of hypernatremia. Discuss briefly what will happen to neuronal cell volume and neuronal interstitial volume . And what extreme procedure could be used to reverse this condition ?
( for a hint:http://www.sciencedirect.com/science/article/pii/S0736467913002023 )
Fourth Question
In the figure below, DRAW the important spinal tracts that run up and down within the spinal cord. Make this CLEAN and clearly visible. Put the ascending tracts on the left side and the descending tract on the right side of the spinal cord. You can use different colors to indicate the ascending and descending tracts.
In your finished figure above, number the different ascending tracts from 1,2… and so on. Mark the descending tracts with A, B,C,.. and so on.
On the following page you will provide next to the corresponding number or letter, the name of each tract and the function of that specific tract (using full sentences). In other words, what information is being carried in these tracts ! Adjust the spacing and add more tract numbers or letters where required ( and there are more than 3 for each). Use complete sentences.
Information for all of this can be found in your textbook There is no reason for this to be not complete.
Ascending tracts
1 =
2.
3.
Descending tracts
A.
B.
C.
Case Presentation on Spinal Cord Injuries
Introduction
The spinal cord carries messages between the brain and the rest of the body. Traumatic injury to the spinal cord can result in a condition called acute spinal cord injury (SCI), resulting in motor, sensory, or autonomic dysfunction which may be temporary or permanent. SCI is a common cause of permanent disability and death in both children and adults. Bike accidents and diving into unexplored shallow waters are the typical reasons why the average person ends up with SCI.
Before attempting to answer the questions associated with this case, students should review the functional anatomy of the spinal cord as well as the normal physiology of spinal reflexes. The questions following this case study can be researched properly and decent answers using complete sentences are expected. The more effort you put into this, the more you will learn about spinal cord injuries and the better your score will be. Use this as an opportunity to educate yourself about these accidents.
The Case
Jason Hendrix is a 21-year-old senior at the University of Texas, majoring in economics. While on spring break in Florida, Jason was involved in a one-vehicle motorcycle accident. In the accident, Jason was thrown from his bike to the pavement, landing on his back. A police officer witnessed the accident and immediately called for medical assistance. Emergency personnel arrived within minutes, and upon recognizing the seriousness of Jason’s back injury, immobilized his neck and secured him to a rigid board prior to transporting him to the emergency room of the nearest hospital.
When he arrived at the hospital, Jason was conscious and complained of pain in his lower back. Upon examination by the emergency room personnel, Jason was found to have numerous abrasions and contusions, and loss of both sensation and motor control of his legs. After he was stabilized, a complete neurological exam was performed to assess and localize Jason’s injury. The neurological exam revealed the following:
Jason demonstrated normal or near normal strength in flexing and extending his elbows, extending his wrists, and when flexing his middle finger and abducting his little finger on both hands. However, he exhibited no movement when medical personnel tested his ability to flex his hips, extend his knees, and dorsiflex his ankles. Stretch reflexes involving the biceps, brachioradialis, and triceps muscles were found to be normal, while those involving the patella and ankle were absent. In addition, Jason was found to have normal sensitivity to pin prick and light touch in areas of his body above the level of his inguinal (groin) region, but not below that region of the body.
The Questions
Answer in complete sentences. Don’t provide listings, bulleted answers, or fragments of sentences. Provide answers under each question. You should have at least two pages when finished with these questions.
1) Define the terms reflex and identify the components of a reflex arc.
2) What is the difference between a reflex and a reaction and explain which one would occur faster than the other.
3) What is the difference between a somatic reflex and a visceral reflex ?
2) Define the term spinal cord injury (SCI), neurological level of injury, tetraplegia, and paraplegia.
3) What is the state of prevalence of SCI in the USA ? In other words, what are the medical statistics for people suffering SCI per year ( I want several sentences with real data here… look it up ! The internet is a wonderful tool.)
4) Define the terms dermatome and myotome and explain how each relates to SCI or how it can be used to diagnose SCI.
5) Explain how a stretch reflex works and describe how such reflexes are used to anatomically localize SCI.
6) Based upon the results of Jason’s neurological exam, what is the neurological level of his SCI? In other words, where specifically in the spinal cord is his damage located ?
For this last question, I want to see a discussion on why you excluded each region of the spinal cord according to the neurological exam. For example, if you decide that the cervical spinal segments are not the problem, why did you decide this ? Clinical examinations are like court cases; statements without evidence to back up your statements are of no use. Answers are in textbook, labmanual …
Please show some effort in your approach. Answer the questions completely and with full sentences. Use your textbook or Google for the information requested.
Fifth set of questions.
Explain what the term channelopathies means. Give an example of a channelopathy related disease and explain the cause of the disease and the symptoms involved. Finally explain the fainting goat phenomena within the context of channelopathies !