intro to physiology Flashcards
What is the greek translation of physiology?
The study of nature
What is the actual definition of physiology?
the branch of science that MECHANISTICALLY explains the NORMAL FUNCTIONING of living organisms
What is a system?
- It is parts that function together
- physiology is the functional viewpoint of the interconnected mechanisms
What are some examples of systems?
- nervous system
- respiratory system
- cardiovascular system
On what 3 levels can physiology be studied?
- the patient
- the organ
- the cell
Give 3 reasons why physiology is important for medicine
- understanding what is happening in the patient
- why current cures are failing
- making better cures
What is pathophysiology?
the mechanism by which a disease process causes the organ to fail
Explain the pathophysiology behind how diabetes affects a patient, starting from the cell
- type 1 diabetes mellitus (autoimmune destruction of beta cells)
- insufficient insulin
- hyperglycaemia
- inability of kidney to reabsorb glucose
- glucose in urine (sign)
- excess fluid loss into urine (sign)
- loss of glucose
- weight loss, hunger, thirst and fatigue (symptoms)
What are the 4 types of functional tissue?
- muscle
- nervous
- epithelial
- connective
What are the functions of muscle?
- drive movement
- shape changes
What are examples of muscle tissue?
- cardiac muscle
- skeletal muscle
- smooth muscle
What is the function of nervous tissue?
communicates signals rapidly
Give examples of nervous tissue
- brain
- peripheral nerve
What are the functions of epithelial tissue?
- controls and transports fluids
- forms barriers for protection
Give examples of epithelial tissue
- gastrointestinal lining
- respiratory lining
What is the function of connective tissue?
supports, protects and repairs structure and shape
Give examples of connective tissue
- bone
- cartilage
- RBC
Give an example of how understanding of electricity has helped in medicine
- ECG (electrocardiography)
- measures the electrical field given off by all the heart muscle cells acting in synchrony
- it can reveal if someone is having a heart attack (acute myocardial infarction)
What are the 8 physiological vital signs?
- heart/pulse rate
- blood pressure
- respiratory rate
- temperature
- oxygen saturation
- URINE production
- confusion/mental state
- pain (actually a symptom)
How are the physiological vital signs important?
they provide a functional (NOT structural) read out of crucial internal organ systems essential for life
Why does physiology require problem solving?
- vital signs represent separate systems, and they influence each other
- functional problems do not show us the source
- it gives us indirect information about what is wrong, but not direct info
Give an example of how problem solving is necessary in physiology
- high temperature implies infection
- but a high temperature is not “caused” by bacteria
- and there could be other causes of high temperature besides infection
What is homeostasis?
the regulation of the cell/bodys internal environnement (extracellular fluid) so that it tends to maintain a stable, constant condition
How many cells are in the human body?
100 trillion (10^14)
What are the 3 general principles of negative feedback?
- stability /set point
- opposing influences
- sensors
Give an example of STABILITY in negative feedback?
- thermoregulation
Explain the positive feedback loop for birth
- baby is in the womb
- perturbation: baby moves forward
- cervix is stretched
- SENSOR: stretch receptors in cervix detect stretch
- pituitary gland releases oxytocin
- uterus contracts, pushing the baby forward more
What are the 3 general principles of positive feedback?
- amplification
- all-or-none
- the 2 stages: extrinsic (initiate) and intrinsic (amplify)
Give an example of AMPLIFICATION in positive feedback
sucking and lactation
Give an example of ALL-OR-NONE in positive feedback
parturition (childbirth)
Give an example for the EXTRINSIC and INTRINSIC stages in positive feedback
- extrinsic: action potential
- intrinsic: depolarisation
Give an example of OPPOSING INFLUENCES in negative feedback?
insulin and glucagon
Give an example of SENSORS in negative feedback?
baroreceptors
What does physiological mean?
it covered the normal function in the body, usually to do with salts or electrolytes
What is the difference between a sign and a symptom?
- a sign is something that is objectively different, showing an altered state
- a symptom is something a patient tells you, that you cannot necessarily obsevre
