I would love some help with these questions, please. Thank you. Select one of th
ID: 3165517 • Letter: I
Question
I would love some help with these questions, please. Thank you.
Select one of the five vital functions listed in the introduction.
Blood pH (electrolytes)
Blood pressure
Body fluid levels (water)
Body temperature
O2 and CO2 levels
Summarize the processes by which the human body maintains homeostasis of this variable, including:
What is the set point for this variable? (i.e. what is the ‘normal’ resting range?)
How is this determined?
What can cause a shift in the range?
What stimuli can produce a change in this variable? Try to list 3 distinct examples.
What sensor mechanism(s) does the body employ to detect changes in the variable?
What are the body’s primary effectors for regulating this variable?
What external factors could increase the effectors’ ability to regulate this variable? Try to list 2 distinct examples.
What external factors could decline the effectors’ ability to regulate this variable? Try to list 2 distinct examples.
Give an example of a medical disease/condition which impairs the body’s ability to regulate this variable. Briefly summarize:
the pathology of this disorder (i.e. where does the feedback mechanism break down?)
symptoms experienced by the patient when this variable is “off balance”
the resultant impact on body function- what happens to body tissues/organs/organ system(s) when this variable is not maintained?
Explanation / Answer
Blood Pressure
Normal point : 120mm Hg - Systolic pressure
80mm Hg - Diastolic Pressure
Various disorders can cause alteration in BP:
1- Stroke
2- Heart attack and heart Failure
3- Blood clots
4- Aneurysm
5- Kidney disease
6- Thickened, narrow or torn blood vessels in the eyes.
7- Metabolic syndrome
8- Brain function and memory problems
Three stimulus :
1- Stress which would cause catecholamine release may lead to increase in BP
2- Hypovolemia due to blood loss and diuretics cause Sodium and water retention and will lead to increase in BP.
3- Noxious stimuli will lead to sympathetic stimulation which would lead to Increase in BP.
Sensor mechanisms in body :
1- Baroreceptors on carotid body and aorta.
2- Renin and Angiotensin system
The bodies primary effectors are : Blood vessels , Adrenal medulla and Kidneys
The two external factors which increase their ability is :
A- Exercise : exercise improves the physiological regulation of BP specially those affecting the cardiovascular system.
B- Drugs enhancing the effect of the effectors.
Stimuli decreasing the ability of the effector mechanism :Drugs which are toxic to the systems decreasing their functions
In 95 percent of the cases , hypertension is essential , in rest 5 percent it can be renovascular hyper tension.
Kidney diseases lead to the developement of Blood pressure . The feedback mechanism breaks at the level of renin angiotensin system.
Normally , when the amount of sodium reaching macula is less , there occurs release of renin from JG cells . This converts angiotensinogen to angiotensin1 which is converted by Angiotensin converting enzyme to angiotensin 2 which cause sodium and water and restored blood volume.
Symptoms of off balance Blood pressure :
High blood pressure on different organs :
Heart : Hypertensive heart disease - This leads to hypertrophy of the ventricles following which there occure heart failure due to improper filling.
Atherosclerosis : Hypertension is the major risk factor . Turbulent blood flow cause thrombosis and formation of atherosclerotic plaques.
Cerebral ischemia : Due to vasoconstriction of cerebral blood vessels , there can occur stroke and dementia .
Eyes : Vision loss can occur due to ischemia
Sexual dysfunction like erection and ejaculation wont occur properly.
Low blood pressure can cause following symptoms :
1- cold clammy skin
2- depression
3-fatigue
4-depression
5-dizziness and light headedness
5- Nausea and vomiting