Lecture 29 Flashcards
Does our body fluctuate around the set point?
Yes
What is a normal range?
Each individual has a normal range which their levels of a given variable fluctuate
What is the population reference range?
It is based on the breadth of individual normal ranges within a population
Does the populations reference range tend to be wider than normal fluctuations than within an individual?
Yes
Is an individuals range more narrow or wider than the population?
Narrow
What happens if an individual starts to move outside the normal range?
May lead to symptoms of a disorder, even when hormone levels are within the population reference range.
Are all individuals set point the same as the population?
Most individuals have a set point within the population reference but not the exact same as one another.
Which physiological variables are maintained homeostatically through hormones?
- Blood sugar concentration
- Growth and repair
- Basal metabolic rate
- Blood calcium concentration
- Body /water /osmolarity /composition
- Hunger
- Blood pressure / volume
- Red blood cell count
- Circadian rhythms
- Factors relating to sexual maturity and reproduction
Does each physiological variable have different hormones?
Yes
What is negative feedback?
Reduce the change until the stimulus is removed or directly inhibit further release REMMERMERMEMBWR
How do you maintain the effects of hormones?
Need to maintain hormone levels
What happens when there is a problem with hormone levels?
Hypo secretion and hyper secretion
What happens when there is a problem with hormone receptors?
Hyposensitive and hypersensitive
What can hormone problems be caused by?
Autoimmunity
Genetic mutation
Tumours and many others
How is diabetes mellitus diagnosed?
Glucose tolerance test, insulin levels, and longer-term exposure (HbA1c test)
What types of stress are there?
Mental stress, overpopulation so stress on people and environment, natural disasters which again causes physical, mental and environment stress and famine so prolonged starvation can cause massive stressors on the body.
Are all types of stress bad for you? and why/ why not?
No, appropriate levels of exercise are good for you as it can aid reaction times, also to get away from a dangerous environment.
What are some common visceral reflexes?
- Cardioacceleratory reflex- increase in heart rate and force of contraction
- Vasomotor reflexes- changes in diameter of peripheral vessels
- Pupillary light reflex- Changes in pupil diameter
What are the affects at the flight, fight or fright mode?
Increased mental alerteness, energied used by all cells, sweat gland secretion, heart rate and respiratory rate, mobilisation of glycogen and lipid reserves, changes in circulation, reproduction in digestive activity and urine production.
What are some effects on the body from stress?
Hair loss, mouth ulcers, random tremors, cardiovascular disease and mental and emotional problems
How do you overcome stress?
Take a little time off, but not too much or it’ll build back up.
What is a hyperparathyroidism tumour and what can occur from them?
Leads to excess PTH secretion, then bones become soft, deformed and fragile, raises the blood levels of calcium and phosphate ions. Then promotes formation of kidney stones composed of calcium phosphate deposits
What is goitre and what occurs?
An iodine deficiency disorder which leads to thyroid gland is unable to make enough TH, when stored TH is depleted to stimulate the thyroid gland to make more TH, without iodine TH cannot be made.
What is the results from goitre?
Loss of negative feedback control and overstimulation of the thyroid gland and excess TSH stimulates growth of the thyroid gland
What are some examples where you need to change set point to maintain homeostasis
- Change in altitude causes a change in blood count for oxygen carrying capacity
- Shift to a location with different climate causes a change in BMR
- Fever causes a change in set point temporarily
