HUBS 191 FINAL EXAM 2026 COMPLETE
QUESTIONS ANSWERS PREMIUM STUDY GUIDE
◉ Typical core body temperature
Answer: 'Core' Body Temperature is generally maintained between
36 to 37.5 C which allows for optimal
metabolic and physiological functioning. Oral and axillary
temperatures are usually about 0.5 C less
than rectal (core). 'Peripheral temperature' is more variable.
◉ Core Body Temperature - Why is it so important?
Answer: At higher temperatures proteins start to denature. At lower
temperatures, chemical reactions slow down, preventing normal cell
function. As cells of the nervous system become compromised, the
ability to thermoregulate is lost. Rapid worsening of the initial
condition and accelerated movement of temperature away from
normal leading toward death. This is an example of a viscous cycle
and a detrimental positive feedback loop.
◉ Diffusion
Answer: Diffusion results from the random movement of individual
molecules as a consequence of their thermal energy. Distance
travelled is proportional to the square root of time - It takes four
times as long to diffuse twice as far OR, quarter of the time to diffuse
,half the distance. Diffusion is therefore very rapid over the short
distances within cells and between cells and capillaries.
◉ What substances are able to diffuse directly through the lipid
bilayer of our cells from regions of high to low concentration (down
their concentration gradient)?
Answer: Oxygen
Carbon dioxide
Steroid hormones
Anaesthetic agents
Such diffusion is passive because the net direction of movement is
'downhill' and so requires no energy input from the body.
◉ Many other substances (because of their size or physiochemical
properties) are not able to 'dissolve' in the lipid bilayer. How do they
cross?
Answer: Water diffuses through protein channels known as
aquaporins. There are specific channels for many ions e.g. K+, Na+
and Ca++
◉ Types of membrane channels used in simple diffusion
Answer: Channels are usually specific and may be open/close
spontaneously (leak channels) or in response to various stimuli e.g.
,chemicals (ligand gated), change in membrane potential (voltage
gated).
◉ Carrier Mediated Passive Transport is also known as facilitated
diffusion, what is this process?
Answer: Substance binds to carrier on one side of the membrane
which induces the carrier to change shape and release of substance
to the other side. ("Downhill" i.e. down conc. gradient).
For example, glucose entry into cells when insulin is present.
◉ Passive vs Active transport
Answer: Passive transport moves molecules down their
concentration gradient and requires no energy whereas active
transport moves molecules against their concentration gradient and
requirers energy.
◉ Primary Active Transport description, example and function.
Answer: Energy from the hydrolysis of ATP used to
move substances against their concentration gradient.
e.g. The sodium-potassium pump which moves 3 Na+ out of the cell
in exchange for 2 K+.
, - maintains ionic gradients
- helps regulate cell volume
◉ Exocytosis and Endocytosis
Answer: Substances transported out of (or into) the
cell in membranous (bilayer) vesicles.
Physiological examples:
- Secretion of insulin by β cells of pancreas (exocytosis)
- Phagocytosis of microbes by neutrophils (endocytosis)
◉ What is osmosis?
Answer: Osmosis is the net movement of water across a membrane
down its own concentration gradient (or toward the region of higher
solute concentration).
Differences in solute concentration across cell membranes can cause
fluid shifts and create pressure that can damage cells.
◉ What is osmolarity and normal osmolarity in ECF and ICF.
Answer: Osmolarity is a measure of the total number of solute
particles per litre of solution. Units are osmol/L or mosmol/L.
Normally 275-300 mosmol/L in ECF and ICF.
QUESTIONS ANSWERS PREMIUM STUDY GUIDE
◉ Typical core body temperature
Answer: 'Core' Body Temperature is generally maintained between
36 to 37.5 C which allows for optimal
metabolic and physiological functioning. Oral and axillary
temperatures are usually about 0.5 C less
than rectal (core). 'Peripheral temperature' is more variable.
◉ Core Body Temperature - Why is it so important?
Answer: At higher temperatures proteins start to denature. At lower
temperatures, chemical reactions slow down, preventing normal cell
function. As cells of the nervous system become compromised, the
ability to thermoregulate is lost. Rapid worsening of the initial
condition and accelerated movement of temperature away from
normal leading toward death. This is an example of a viscous cycle
and a detrimental positive feedback loop.
◉ Diffusion
Answer: Diffusion results from the random movement of individual
molecules as a consequence of their thermal energy. Distance
travelled is proportional to the square root of time - It takes four
times as long to diffuse twice as far OR, quarter of the time to diffuse
,half the distance. Diffusion is therefore very rapid over the short
distances within cells and between cells and capillaries.
◉ What substances are able to diffuse directly through the lipid
bilayer of our cells from regions of high to low concentration (down
their concentration gradient)?
Answer: Oxygen
Carbon dioxide
Steroid hormones
Anaesthetic agents
Such diffusion is passive because the net direction of movement is
'downhill' and so requires no energy input from the body.
◉ Many other substances (because of their size or physiochemical
properties) are not able to 'dissolve' in the lipid bilayer. How do they
cross?
Answer: Water diffuses through protein channels known as
aquaporins. There are specific channels for many ions e.g. K+, Na+
and Ca++
◉ Types of membrane channels used in simple diffusion
Answer: Channels are usually specific and may be open/close
spontaneously (leak channels) or in response to various stimuli e.g.
,chemicals (ligand gated), change in membrane potential (voltage
gated).
◉ Carrier Mediated Passive Transport is also known as facilitated
diffusion, what is this process?
Answer: Substance binds to carrier on one side of the membrane
which induces the carrier to change shape and release of substance
to the other side. ("Downhill" i.e. down conc. gradient).
For example, glucose entry into cells when insulin is present.
◉ Passive vs Active transport
Answer: Passive transport moves molecules down their
concentration gradient and requires no energy whereas active
transport moves molecules against their concentration gradient and
requirers energy.
◉ Primary Active Transport description, example and function.
Answer: Energy from the hydrolysis of ATP used to
move substances against their concentration gradient.
e.g. The sodium-potassium pump which moves 3 Na+ out of the cell
in exchange for 2 K+.
, - maintains ionic gradients
- helps regulate cell volume
◉ Exocytosis and Endocytosis
Answer: Substances transported out of (or into) the
cell in membranous (bilayer) vesicles.
Physiological examples:
- Secretion of insulin by β cells of pancreas (exocytosis)
- Phagocytosis of microbes by neutrophils (endocytosis)
◉ What is osmosis?
Answer: Osmosis is the net movement of water across a membrane
down its own concentration gradient (or toward the region of higher
solute concentration).
Differences in solute concentration across cell membranes can cause
fluid shifts and create pressure that can damage cells.
◉ What is osmolarity and normal osmolarity in ECF and ICF.
Answer: Osmolarity is a measure of the total number of solute
particles per litre of solution. Units are osmol/L or mosmol/L.
Normally 275-300 mosmol/L in ECF and ICF.
