BIO 2301 HUMAN PHYSIOLOGY -
EXAM 1 QUESTIONS WITH CORRECT
ANSWERS
Facilitated diffusion - ANSWER-Movement of specific molecules across cell
membranes through protein channels
Factors affecting Rate of diffusion - ANSWER-1. size (smaller faster)
2. polarity (non polar faster)
2. concentration gradient (bigger difference faster)
Osmosis - ANSWER-- The unassisted diffusion of water across a selective
permeable membrane
- Water will go through an aquaporin (a pore) and will move from where there is
more water to where there is less water (high to low) OR movement of water from an
area of low solute concentration to an area of high solute concentration
- Happens when the membrane is not permeable to the solutes
Osmotic pressure - ANSWER-- The pressure needed to stop osmosis
- Water follows salt concept
- The more particles there are, the greater the osmotic pressure
Osmolarity - ANSWER-- The concentration of solute particles in a solution
- NaCl and NH4Cl= x2
- Glucose and Urea = x2
- Must be constantly maintained or neurons will be damaged - osmoreceptors in the
hypothalmus detect increased in osmolarity (due to dehydration) which triggers
antidiuretic hormone release, thrist, and decresed excretion of water in urine
Inside a cell - ANSWER-.3 osmoles/liter or 300m osmoles/liter
Tonicity - ANSWER-- The ability of a solution to affect a cell - cell volume will
increase and decrease according to the concentration of the solute surrounding it
- It involves the number of nonpenetrating solutes in a solution and take into account
the permeability of the membrane to the solutes and water
- 3 solution types: isotonic, hypertonic, and hypotonic
Isotonic solutions - ANSWER-- Causes no changed in the cell
- Examples: 0.9% NaCl (normal saline), 5% dextrose (D5W), and lactated ringers
solutions (LRS)
- These are the solutions you want to give people intravenously
osmolarity = .3 osmoles/liter
Hypertonic solutions - ANSWER-- Have less water than the cell and so water leaves
the cell to enter the solution
- Causes crenation (shriveling of the cell)
- Examples: mannitol and 50% glucose
,osmolarity > .3 osmoles/liter
Hypotonic solutions - ANSWER-- Have more water than the cell so the water enters
the cell from the solution
- Causes the cell to swell and lyse (burst)
- Examples: distilled water - never give this intravenously (o = 0)
osmolarity < .3 osmoles/liter
Rules governing permeability - ANSWER-- Generally, nonpolar substances are
permeable (can enter or leave a cell)
- Polar substances may or may not be permeable depending on their size - small
polar substances can fit through pores in the membrane where as large ones cannot
Nervous system - ANSWER-Involved in communication and control
Central - ANSWER-processes, integrates, stores, and responds to information from
the PNS
brain and spin cord
Peripheral - ANSWER-detects stimuli and transmits information to the CNS and
receives information from the CNS
nervous tissues and sensory receptors
Peripheral function - ANSWER-Sensory- afferent (toward the CNS): transmits action
potentials from sensory receptors to the CNS
Motor- efferent (away from the CNS): carries action potentials away from the CNS in
cranial or spinal nerves (two subdivisions)
Neuron (nerve cell) - ANSWER-- The main cell and the functional unit of the nervous
system
- Allows for the communication and control by nerve impulses - aka action potentials
- Have a cell body (which contain organelles), many dendrites (the receptive regions
of the neuron), and a single axon (the area of the neuron that generates and
propagates the action potential)
- At the end of the axon there are many telodendria (branches) and at the end of
each telodendria there is a axonal terminal (aka bouton)
- Neurotransmitters are chemicals found in the axonal terminals
Solution components - ANSWER-water plus a substance = a solution (solute (Na+ or
glucose) or solvent (water))
Polar substances - ANSWER-dissolve in water; covalent bond between two or more
dissimilar atoms, in which electrons are shared unequally; are charged and must use
a channel; must use transport proteins; water is polar/hydrophilic
Nonpolar substances - ANSWER-do not dissolve in water; not soluable and
hydrophobic; cell membrane is usually lipid meaning it passes easily; lipids are non
polar
Solubility - ANSWER-- Like dissolves like
, - Polar liquids dissolve polar substances
- Nonpolar liquids dissolve nonpolar substances
Cell membrane transport - ANSWER-Substances need to move between fluid
compartment such as extracellular to intracellular and the other way around
Passive mechanisms - ANSWER-diffusion, facilitated diffusion, osmosis, filtration;
movement of ions and other atomic or molecular substances across cell membranes
without need of energy input
Active - ANSWER-the movement of ions or molecules across a cell membrane into a
region of higher concentration, assisted by enzymes and requiring energy
What substances can easily pass through the phospholipid bilayer of cell
membranes? - ANSWER-- Nonpolar substances will pass through easily
- Polar substances must go through a channel in the cell membrane
Diffusion - ANSWER-- The movement of small molecules from an area of high
concentration to an area of low concentration
- Does not require ATP energy
- Consists of a solute (molecules being dissolved) and a solution (water)
- Nonpolar, small lipid-soluble molecules will easily pass through the lipid bilayer
Somatic nervous system - ANSWER-Controls skeletal muscle and is under voluntary
control
Autonomic nervous system - ANSWER-- Controls smooth muscle, cardiac muscle,
and glands
- Involuntary control
- Two divisions: sympathetic and parasympathetic
Sympathetic nervous system - ANSWER-Fight or flight
Parasympathetic nervous system - ANSWER-Rest and digest
Action Potentials - ANSWER-- Nerve impulses
- Messages in the nervous system - the way neurons communicate
- Electrical events so they involve the flow of ions (Na and K) into and out of the axon
- Generated at the axon hillock (beginning of the axon)
- Travels down the axon towards the axonal terminal where it will cause the release
of a neurotransmitter
- The neurotransmitter will carry the message from that neuron across the space to
the next neuron
Electronegative - ANSWER-Inside of neuron is negative with respect to the outside
Schwann cells - ANSWER-Supporting cells of the peripheral nervous system
responsible for the formation of myelin
EXAM 1 QUESTIONS WITH CORRECT
ANSWERS
Facilitated diffusion - ANSWER-Movement of specific molecules across cell
membranes through protein channels
Factors affecting Rate of diffusion - ANSWER-1. size (smaller faster)
2. polarity (non polar faster)
2. concentration gradient (bigger difference faster)
Osmosis - ANSWER-- The unassisted diffusion of water across a selective
permeable membrane
- Water will go through an aquaporin (a pore) and will move from where there is
more water to where there is less water (high to low) OR movement of water from an
area of low solute concentration to an area of high solute concentration
- Happens when the membrane is not permeable to the solutes
Osmotic pressure - ANSWER-- The pressure needed to stop osmosis
- Water follows salt concept
- The more particles there are, the greater the osmotic pressure
Osmolarity - ANSWER-- The concentration of solute particles in a solution
- NaCl and NH4Cl= x2
- Glucose and Urea = x2
- Must be constantly maintained or neurons will be damaged - osmoreceptors in the
hypothalmus detect increased in osmolarity (due to dehydration) which triggers
antidiuretic hormone release, thrist, and decresed excretion of water in urine
Inside a cell - ANSWER-.3 osmoles/liter or 300m osmoles/liter
Tonicity - ANSWER-- The ability of a solution to affect a cell - cell volume will
increase and decrease according to the concentration of the solute surrounding it
- It involves the number of nonpenetrating solutes in a solution and take into account
the permeability of the membrane to the solutes and water
- 3 solution types: isotonic, hypertonic, and hypotonic
Isotonic solutions - ANSWER-- Causes no changed in the cell
- Examples: 0.9% NaCl (normal saline), 5% dextrose (D5W), and lactated ringers
solutions (LRS)
- These are the solutions you want to give people intravenously
osmolarity = .3 osmoles/liter
Hypertonic solutions - ANSWER-- Have less water than the cell and so water leaves
the cell to enter the solution
- Causes crenation (shriveling of the cell)
- Examples: mannitol and 50% glucose
,osmolarity > .3 osmoles/liter
Hypotonic solutions - ANSWER-- Have more water than the cell so the water enters
the cell from the solution
- Causes the cell to swell and lyse (burst)
- Examples: distilled water - never give this intravenously (o = 0)
osmolarity < .3 osmoles/liter
Rules governing permeability - ANSWER-- Generally, nonpolar substances are
permeable (can enter or leave a cell)
- Polar substances may or may not be permeable depending on their size - small
polar substances can fit through pores in the membrane where as large ones cannot
Nervous system - ANSWER-Involved in communication and control
Central - ANSWER-processes, integrates, stores, and responds to information from
the PNS
brain and spin cord
Peripheral - ANSWER-detects stimuli and transmits information to the CNS and
receives information from the CNS
nervous tissues and sensory receptors
Peripheral function - ANSWER-Sensory- afferent (toward the CNS): transmits action
potentials from sensory receptors to the CNS
Motor- efferent (away from the CNS): carries action potentials away from the CNS in
cranial or spinal nerves (two subdivisions)
Neuron (nerve cell) - ANSWER-- The main cell and the functional unit of the nervous
system
- Allows for the communication and control by nerve impulses - aka action potentials
- Have a cell body (which contain organelles), many dendrites (the receptive regions
of the neuron), and a single axon (the area of the neuron that generates and
propagates the action potential)
- At the end of the axon there are many telodendria (branches) and at the end of
each telodendria there is a axonal terminal (aka bouton)
- Neurotransmitters are chemicals found in the axonal terminals
Solution components - ANSWER-water plus a substance = a solution (solute (Na+ or
glucose) or solvent (water))
Polar substances - ANSWER-dissolve in water; covalent bond between two or more
dissimilar atoms, in which electrons are shared unequally; are charged and must use
a channel; must use transport proteins; water is polar/hydrophilic
Nonpolar substances - ANSWER-do not dissolve in water; not soluable and
hydrophobic; cell membrane is usually lipid meaning it passes easily; lipids are non
polar
Solubility - ANSWER-- Like dissolves like
, - Polar liquids dissolve polar substances
- Nonpolar liquids dissolve nonpolar substances
Cell membrane transport - ANSWER-Substances need to move between fluid
compartment such as extracellular to intracellular and the other way around
Passive mechanisms - ANSWER-diffusion, facilitated diffusion, osmosis, filtration;
movement of ions and other atomic or molecular substances across cell membranes
without need of energy input
Active - ANSWER-the movement of ions or molecules across a cell membrane into a
region of higher concentration, assisted by enzymes and requiring energy
What substances can easily pass through the phospholipid bilayer of cell
membranes? - ANSWER-- Nonpolar substances will pass through easily
- Polar substances must go through a channel in the cell membrane
Diffusion - ANSWER-- The movement of small molecules from an area of high
concentration to an area of low concentration
- Does not require ATP energy
- Consists of a solute (molecules being dissolved) and a solution (water)
- Nonpolar, small lipid-soluble molecules will easily pass through the lipid bilayer
Somatic nervous system - ANSWER-Controls skeletal muscle and is under voluntary
control
Autonomic nervous system - ANSWER-- Controls smooth muscle, cardiac muscle,
and glands
- Involuntary control
- Two divisions: sympathetic and parasympathetic
Sympathetic nervous system - ANSWER-Fight or flight
Parasympathetic nervous system - ANSWER-Rest and digest
Action Potentials - ANSWER-- Nerve impulses
- Messages in the nervous system - the way neurons communicate
- Electrical events so they involve the flow of ions (Na and K) into and out of the axon
- Generated at the axon hillock (beginning of the axon)
- Travels down the axon towards the axonal terminal where it will cause the release
of a neurotransmitter
- The neurotransmitter will carry the message from that neuron across the space to
the next neuron
Electronegative - ANSWER-Inside of neuron is negative with respect to the outside
Schwann cells - ANSWER-Supporting cells of the peripheral nervous system
responsible for the formation of myelin
