introduction to physiology

Question 1

what is physiology

Answer 1

-science of life
-the emphasis of integrating molecular, cellular, systems and whole body function is what distinguishes physiology from the other life sciences

Question 2

what does physiology help us understand

Answer 2

-how a healthy body works (how we function)
-how to maintain health and age well
-how living organisms cope with or adapt to different environments e.g. temperatures, altitudes
-what goes wrong with diseases
-how to treat diseases

Question 3

facts about the internal environment

Answer 3

-cells need a carefully regulated fluid environment to function
-internal environment must stay stable despite changes to the external environment
-homeostasis is what regulates constant steady state of the internal environment
-keeping the internal environment in a steady state needs energy input therefore is an active process

Question 4

what’s the intracellular fluid

Answer 4

-fluid found inside of cells

Question 5

what does the extracellular fluid consist of

Answer 5

-blood plasma (fluid that flows through blood vessels
-interstitial fluid (any fluid surrounding outside of cells)

Question 6

what must be regulated in the blood plasma

Answer 6

-oxygen
-glucose
-ions - Ca2+, K+, Na+, H+ (Ph)
-volume

Question 7

what must be regulated in the interstitial fluid

Answer 7

-glucose
-ions - Ca2+, K+, Na+, H+ (Ph)

Question 8

what must be regulated in the intracellular fluid

Answer 8

-ATP
-glucose
-ions - Ca2+, K+, Na+, H+ (Ph)
-volume

Question 9

what needs to be regulated in the whole body

Answer 9

-arterial blood pressure so oxygen can travel to cells
-core temperature so reaction will occur at the right rate
-glucose is regulated throughout all fluids for energy
-ions are all also regulated in all fluids which allows different types of reactions to occur

Question 10

what are the 4 essential components in a negative feedback loop

Answer 10

1) receptors: sense the vital parameter
2) control centre: compares input against a set point
3) output signal: signal from control centre to effector
4) effector: enables a change to return vital parameter

Question 11

what’s a negative feedback loop

Answer 11

something is disrupted, body makes changes to bring body body back to normal state

Question 12

thermoregulation: a negative feedback loop

Answer 12

-physiological adjustment in the opposite direction
-returns parameters back to their original values
-redundancy- multiple mechanisms present for many vital parameters (lots of different ways to return body back to normal for temperature for an example)

Question 13

what’s the total body water for a 70kg male

Answer 13

42 litres - 60% of body weight
-this varies for women (35 litre, 50%)

Question 14

what’s the osmolality of the internal environment

Answer 14

-osmolalaty is the total concentration of all particles that are free in a solution measured in mOsm (milliosomoles per kg of water)
-all of the internal environment is the same as don’t want cells to shrink or expand

Question 15

distribution of ions in ECF

Answer 15

-Na+= 145mM
-K+= 4.5mM
-Cl-= 116mM
-Ca2+=1mM
-more NaCl in ECF

Question 16

distribution of ions in ICF

Answer 16

-Na+= 15mM
-K+= 120mM
-Cl-= 20mM
-Ca2+=0.0001mM

Question 17

what does a phospholipid bilayer consist of

Answer 17

-amphipathic
-hydrophilic head
-polar
-interact with water
-hydrophobic tail
-non-polar
-interact poorly with water

Question 18

permeability of cell membrane

Answer 18

-impermeable to large molecules, and charged water soluble substances
-permeable to hydrophobic molecules e.g. O2, CO2, steroid hormones
-partially permeable to uncharged, polar molecules

Question 19

what do membrane proteins do in the cell membrane

Answer 19

-membrane proteins allow polar molecules e.g. ions, sugars, amino acids, nucleotides, water to pass through the membrane
-molecules can avoid the hydrophobic core of the phospholipid bilayer