SESSION 1 Flashcards
(45 cards)
Explain the changes in the heart and lung function when exercising
Heart rate increases- pump more nutrients and oxygen to the muscles
Respiratory rate increases- increase uptake of oxygen and faster removal of carbon dioxide
A fit person has a lower pulse rate, breathing rate and lactic acid levels than an unfit person
Explain the advantages of using tympanic membrane thermometers
Tympanic thermometers are usually small hand-held devices with a probe that is inserted into the patient’s ear canal, measures the temperature of the tympanic membrane, which is a thin structure that is well perfused with blood
Advantages:
Quick and easy use so temperature can be measured more frequently
Safety- mercury spillage is not a concern
Describe the main cause of increased temperature associated with exercise
Biochemical reaction- heat produced as ATP is converted to ADP
The movement of muscle contractile proteins which would also produce heat
Why is it important for body temperature to be kept within operational limits?
Many mechanisms within the body depend on temperature, e.g. Enzymes
Hypothermia- when a person’s body temperature drops below 35C
Elderly people- can’t move to generate heat
Babies- bodies ability to regulate temperature isn’t fully developed
Hyperthermia- hyperthermia is defined as a temperature greater than 37.5–38.3 °C
The most common causes include heat stroke and adverse reactions to drugs.
Body temperature regulation- temperature too high
Hypothalamus detects change in temperature
Thermostat in the hypothalamus activates cooling mechanisms
Sweat glands activated, increasing evaporative cooling
Vasodilation: capillaries fill with blood and heat radiates from skin surface
Pilorelaxation: hairs flatten
Body temperature decreases
Body temperature regulation- temperature too low
Hypothalamus detects change
Thermostat in hypothalamus activates warming mechanisms
Shivering: rapid contraction and relaxation of skeletal muscles. Heat produced by respiration
Vasoconstriction: arteriolar get smaller to reduce blood going to the skin
Piloerection- hairs stand up
Body temperature increases
Clinical consequence of plasma potassium levels being too high and too low
Hypokalemia- too low
Symptoms: fatigue, constipation, loss of skeletal muscle, low blood pressure, excessive urination, extreme thirst
Causes: use of diuretics, kidney failure
Hyperkalemia- too high
Symptoms: slow heart rate, weakness, death
Causes: release of potassium from dying cells, kidney failure
Clinical consequence of plasma glucose levels being too high and too low
Hypoglycaemia- too low
Symptoms: sweating, hunger, nausea, confusion, seizures
Causes: liver disease, starvation, kidney failure, tumours- insulinoma
Consequence: diabetic coma, weight loss, Nerva damage, joint/ bone problems
Hyperglycaemia- too high
Symptoms: polyphasic(hunger), polydipsia(thirst), polyuria(increased urine)
Causes: diabetics, stress, beta blockers and myocardial infarction
Clinical consequence of plasma calcium levels being too high and too low
Hypocalcemia- too low
Symptoms: heart failure, muscle cramps, seizures, anxiety
Causes:hypoparathyroidism, vitamin D deficiency, kidney failure, pancreatitis, calcium channel blocker overdose
Hypercalcemia- too high
Symptoms: lack of concentration, bradycardia, muscle weakness- death
Causes: overactive parathyroid glands - lung/ breast cancer
Clinical consequence of plasma sodium levels being too high and too low
Hyponatremia- too low
Symptoms:nausea, confusion, headache, fatigue, seizures, coma
Causes:ecstasy, heart/ kidney/ liver problems, dehydration, severe vomiting/ diarrhoea
Hypernatremia- too high
Symptoms:tachycardia, mucosa, weight loss,
Hypertension- neuronal cell shrinkage (Brian injury)
Causes: decrease in total body water, same sodium levels in less water
Define entropy
Entropy means disorder
All living systems aim to minimise entropy and maximise order
Define endogenous signalling molecules
Gaseous molecules synthesised internally, in the organism
Define exogenous I signalling molecules
Natural plant based molecules
E.g. Morphine, antibiotics and aspirin
Define exogenous II signalling molecules
Synthetic man made molecules
E.g. Drugs
Define homeostasis
Maintaining the optimal internal environment for cells to function by physiological processes
Explain how control systems monitor and adjust the extracellular environment according to demand or disturbance to pertains conditions
1) stimulus produces change in variable
2) change detected by receptor
3) input information sent along afferent pathway to control centre
4) output information sent along efferent pathway to effector
5) response of effector feeds back to influence magnitude of stimulus and returns variable to homeostasis
Give examples of physiochemical parameters under homeostatic control
Temperature PH O2 CO2 H2O NA+ K+ Ca2+ Cl- Glucose
Define sensor
Detect physiological parameter
E.g. Core body temperature receptors and peripheral temperature receptors on the skin
Define set point
Compare against sensor signal to detect an error
E.g. Body temperature set point is 37 degrees
Optimum temperature for homeothermic, enzymes and proteins
Define controller
Bring system output back towards set point
E.g. Hypothalamus
Define effector
Set of components that bring about change back to optimal set point
Define the levels at which physiological control feedback loops interact
Synergistically, e.g. Temperature- skin blood supply and sweating
Antagonistically, e.g. Insulin vs glucagon
Define negative feedback
Adjusts the behaviour of the system in the opposite direction of where it is currently going
E.g. Temperature regulation- the body works to lower the temperature if there is an increase in the core temperature
Define extracellular
Situated or taking place outside the cell
