SESSION 1 Flashcards Preview

Cell Physiology And Pharmacology🌟 > SESSION 1 > Flashcards

Flashcards in SESSION 1 Deck (45):

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

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



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


Define intracellular

Located or occurring within the cell


Define endocrine

Relating to glands which secrete hormones directly into the blood

Act over long distance

Major regulation of body function via neuroendocrine system:
- digestion
-metabolism/ respiration
-growth/ development
-behaviours- sexual/ stress response


Define paracrine

Relating to a hormone which has effect only in the area surrounding the gland

Acts on shorter distances- from cell to cell
Induce changes in receptor cells

E.g. Neurotransmitters- neurone to neurone across a synapse


Define autocrine

Relating to cell- produced substance that has an effect on the cell by which it is secreted

Act over microns when released from cells
Potential cancer treatment


Overview of signalling molecule targets

Classification of drug targets:


Ion channels

Exception: chemotherapy- target is structural protein/ DNA


Overview of signalling molecule: Receptors


Kinase Linked Receptors
Ion channels (Ligand gated)
Nuclear/ Intracellular
G- Protein Coupled Receptors


What is the difference between endogenous and exogenous signalling molecules binding with targets ?

Endogenous signalling molecules- optimal fit for the job

Exogenous signalling molecules - fit may be 'sub- optimal', possible side effects


Describe the major types of endocrine signalling molecules

Hydrophilic 1- amines
Small charged, hydrophilic
Receptors in plasma membrane

Hydrophilic 2- peptides to proteins
Short chain, insulin
Receptors in plasma membrane

Lipophilic- steroids
Derivative from cholesterol
Receptors are intracellular

Refer to comparative table on powerpoint


Describe therapeutic exogenous signalling molecules

Adrenaline- used in A & E
Insulin- controls blood sugar, diabetes
Steroids- used as an anti- inflammatory


Describe the primary signalling role of paracrine signalling molecules

Exhibitory- signal increase firing rate post- synaptically
Inhibitory- signal decrease firing rate post synaptically

Neurones can summate both kinds

Refer to comparative table for common neurotransmitter signalling functions


Local injury result in signalling response provided by paracrine signalling molecules
Local response- rapid, focused and integrated, does not involve he whole body

Define local chemical mediators

Cytokines- interleukins, chemokines, interferons and histamine

Eicosanoids- prostaglandins and leukotrienes

Others- platelet activating factor, nitric oxide and neuropeptides


Define the paracrine therapeutic exogenous signalling molecules

Hypertension- propanol antagonises adrenaline/ noradrenaline used
Parkinsonism- dopamine precursor
Depression- slow re- up take of serotonin
Epilepsy- GABA
Migrating- serotonin agonists

Inflammation- steroids blockers of inflammatory signals
Moderate pan- non steroidal anti- inflammatory black local mediator
Respiratory inflammatory responses- adrenergic agonists
Development for cancer treatment


Explain Kinase Linked Receptors

Mediate signals of wide variety of protein molecules
Act via phosphorylation of specific groups- resulting in a cascade effect


Explain ion channels ligand gate (inotropic receptors)

Many fast neurotransmitters : ACh
Modulating action potential generation in neurones and contraction in muscle
Coupled to Calcium ions


Explain nuclear/ intracellular receptors

Ligand need to be lipid soluble, e.g. Steroids
Activates/ inactivates a gene
Ligand receptor complex binds to gene transcription factor when at the nucleus


Explain G- Protein Coupled Receptors

Largest receptor group
Slow neurotransmitters; serotonin and dopamine
Three major types: Gs, Gi, Gq- activate different intracellular routes


What do ion channels do?

Selectively allow ion current to flow across the plasma membrane
Four major ion currents: Na+, K+, Ca2+, Cl-
Ion channels enable selective flow of ion current down its electrochemical gradient


Regulating ion channels

Ion channel activity can be facilitated or inhibited by phosphorylation of intracellular sites on channels via pKA, pKC and GPCR activation
Binding with exogenous channel blockers


What do transport/ carrier proteins do?

Transport of ions/ small molecules can use channels facilitated diffusion if there is gradient into/ out of the cell
Use ATP as an energy source
Used to transport across GI tract
Transport needed if highly polar or going against gradient


Give an important example of neurotransmitter re- uptake transport


Use co- transport of sodium to drive transport


What do enzymes do?

Targeting enzymes
Competitive inhibition at active binding sites with non- substrate
Increase levels of precursor substrate