Tier 1, Round 1

Section 6.5 (pg. 173 – 184)

Q1: What does CNS and PNS stand for? Which structures in the body constitute

each?

Q1: What does CNS and PNS stand for? Which structures in the body constitute each?

• A1:• CNS is central nervous system• PNS is peripheral nervous system• CNS is composed of the brain and spinal

cord• PNS is composed of the spinal nervesand

cranial nerves

Q2: Arrange the following in the correct order: sensory receptor, effector cells, motor neurons, sensory

neurons, relay neurons. Say which neurons belong to the CNS and which belong to the PNS.

Q2: Arrange the following in the correct order: sensory receptor,

effector cells, motor neurons, sensory neurons, relay neurons. Say which neurons belong to the CNS and which belong to the PNS.

• A2:• sensory receptor > sensory neurons (PNS) >

relay neurons (CNS) > motor neurons (PNS) > effector cells

Q3: What is the “conductor” of a neuron impulse? What does the myelin sheath

do to the action potential?

Q3: What is the “conductor” of an action potential? What does the myelin sheath do to the action potential?

• A3:• The “conductor” of an action potential is the

axon.• The myelin sheath greatly increases the rate

at which an action potential passes down an axon.

Q4: During the resting potential, most Na+ are ____ transported ___ __ the axon and most K+ are

transported ___ the cytoplasm. What other kinds of ions are present, and what do they do?

Q4: During the resting potential, most Na+ are ____ transported

___ __ the axon and most K+ are transported ___ the cytoplasm. What other kinds of ions are present, and what do they do?

• A4:• Most Na+ are activelytransported out ofthe

axon.• Most K+ are transported intothe cytoplasm.• The other ions are negatively charged

organic ionsthat create a net positivecharge outside the axon and a net negative charge inside the axon.

Q5: In an action potential, Na+ diffuses ___ and then K+ diffuses ___. This process is called _______, which is the ‘impulse.’ Once an impulse begins, it continues to

the end of the cell; this is ___-______.

Q5: In an action potential, Na+ diffuses ___ and then K+ diffuses

___. This process is called _______, which is the ‘impulse.’ Once an impulse begins, it continues to the end of the cell; this is ___-______.

• A5:• In an action potential, Na+ diffuses inand

then K+ diffuses out.• This process is called depolarization, which

is the ‘impulse.’• Once an impulse begins, it continues to the

end of the cell; this is self-propagation.

Q6: Once an action potential is sent, what is the process by which Na+ and K+ are returned to their

resting potential places? How is this accomplished?

Q6: Once an action potential is sent, what is the process by which Na+

and K+ are returned to their resting potential places? How is this accomplished?

• A6:• The process by which Na+ and K+ are

returned to their resting potential places is repolarization.• This is accomplished by active transport.

Tier 1, Round 2

Section 6.5 (pg. 173 – 184)

Q7: What is the chemical communication point between pre- and

post- neurons called?

Q7: What is the chemical communication point between pre- and post- neurons called?

• A7:• The chemical communication point between

neurons is the synapse.

Q8: What is the process by which physiological variables are kept within certain limits? Name four

of the five physiological variables listed in the book.

Q8: What is the process by which physiological variables are kept

within certain limits? Name four of the five physiological variables listed in the book.

• A8:• This process is called homeostasis.• Acceptable variables are blood pH, [CO2],

[C6H12O6], body temperature, and water balance.

Q9: What are the physiological changes that tell the body to adjust a value back to a certain point

called? Homeostatic mechanism are controlled by what?

Q9: What are the physiological changes that tell the body to

adjust a value back to a certain point called? Homeostatic mechanism are controlled by what?

• A9:• These physiological changes are called

negative feedback mechanisms.• Homeostatic mechanisms are mostly

controlled by the autonomic nervous system.

Q10: When body temperature is increasing or decreasing too much, the _______ is warned by ________. What are some warming and cooling

mechanisms?

Q10: When body temperature is increasing or decreasing too

much, the _______ is warned by ________. What are some warming and cooling mechanisms?

• A10:• When body temperature is increasing or

decreasing too much, the hypothalamus is warned by thermoreceptors.• Cooling mechanisms: sweatingand

arteriole dilation.• Warming mechanisms: arteriole

constrictionand shivering.

Q11: Negative feedback mechanisms also control blood glucose concentration. What do βcells

secrete? What do α cells secrete? What do these hormones do?

Q11: Negative feedback mechanisms also control blood glucose

concentration. What do β cells secrete? What do α cells secrete? What do these hormones do?

• A11:• In the pancreas, β cells secrete insulin, and

α cells secrete glucagon.• The secretion of insulin causes hepatocytes

to take in glucose and convert it to glycogen.• The secretion of glucagon causes hydrolysis

of glycogen in hepatocytes to release glucose.

Q12: What is type I diabetes? What is type II diabetes? Which is more

common?

Q12: What is type I diabetes? What is type II diabetes?

Which is more common?

• A12:• Type I diabetes is the form of the disease in

which the immune system destroys its own β cells.• Type II diabetes is the form of the disease in

which the body no longer responds to insulin as it should—this is called insulin resistance, and this is the more common form of the disease by far.

Tier 1, Round 3

Section E.1 (pg. 461 – 464)

Q13: Define the terms stimulus, reflex and response.

Q13: Define the terms stimulus, reflex and response.

• A13:• A stimulus is a change in the environment

that is detected by a receptor and elicits a response.• A reflex is a rapid, unconscious response.• A response is a reaction to a stimulus.

Q14: Draw a (rudimentary) picture of the spinal cord and the components of

a reflex arc. Label it, too.

Q14: Draw a (rudimentary) picture of the spinal cord and

the components of a reflex arc. Label it, too.

• A14:

Q15: How are natural selection and the responses of animals to their

environment related?

Q15: How are natural selection and the

responses of animals to their environment related?

• A15:• An animal’s response to its environment can

be considered a series of reflexes.• Some responses allow an animal respond to

its environment more advantageously than another animal with different responses.• Animals with advantageous variations in

their responses survive to reproduce more frequently than those with detrimental variations. Thus, the genetic programming for a particular behavior pattern propagates throughout the population.

Q16: Explain the advantageous behavior exhibited by a segment of the population of European blackcaps in terms of migration.

Q16: Explain the advantageous behavior exhibited by a segment

of the population of European blackcaps in terms of migration.

• A16:• European blackcaps generally migrate from

Germany in the summer to Spain in the winter. Some European blackcaps started migrating to the UK instead. These blackcaps left the UK 10 days earlier than the Spanish wintering birds, and so received the choices places to lay eggs. More eggs were laid by UK birds than Spanish birds.

Q17: Explain the advantageous behavior exhibited by two segments of the population

of Sockeye salmon in terms of habitat.

Q17: Explain the advantageous behavior exhibited by two

segments of the population of Sockeye salmon in terms of habitat.

• A17:• There are two types of habitat: slow, deep

Lake Washington and fast, shallow Cedar River. They’re connected to each other.• There are two types of males: lake males

who are fat and river males who are thin and narrow.• These two segments stopped interbreeding,

because it does no good to have a fat fish in a river.• Voilà. Now there are two different

populations because each was selected by it’s environment.

Q18: Jellyfish belong to which phylum?

Q18: Jellyfish belong to which phylum?

• A18:• cnidaria

Tier 1, Round 4

Section E.4 (pg. 481 – 489)

Q19: What are the molecules that move across the synaptic cleft? What receives these molecules? What are the two types of molecules that move across the

synaptic cleft?

Q19: What are the molecules that move across the synaptic cleft?

What receives these molecules? What are the two types of molecules that move across the synaptic cleft?

• A19:• The molecules that move across the

synaptic cleft are called neurotransmitters.• These molecules are received by receptor

molecules.• The two types of neurotransmitters are

excitatoryand inhibitory.

Q20: What happens when the action potential reaches the axon bulb?

Q20: What happens when the action potential reaches

the axon bulb?

• A20:• Ca2+ rush into the end of the neuron,

causing vesicles containing neurotransmitters to fuse with the presynaptic membrane (i.e. the neurotransmitters are dumped into the synaptic cleft).• The neurotransmitters then bind to specific

receptors on the postsynaptic membrane.

Q21: What do excitatory neurotransmitters do, and how do they

work?

Q21: What do excitatory neurotransmitters do,

and how do they work?

• A21:• Excitatory neurotransmitters generate an

action potential.• Excitatory neurotransmitters make the

postsynaptic membrane especially permeable to positive ions (such as Na+). Positive ions rush in, making the inside of the neuron positive. This launches a depolarization of that particular part of the neuron.• Depolarization self-propagates as per usual,

with Na+ diffusing in and K+ diffusing out.

Q22: What do inhibitory neurotransmitters do, and how do they

work?

Q22: What do inhibitory neurotransmitters do,

and how do they work?

• A22:• Inhibitory neurotransmitters stop an action

potential from continuing to the postsynaptic neuron.• Inhibitory neurotransmitters bind to a

specific receptor and causes hyperpolarization.• Hyperpolarization makes the inside of the

neuron more negative than it was to begin with by moving Cl- in and/or K+ out.

Q23: What is acetylcholine, and with what types of synapses is it used? How

does acetylcholine work?

Q23: What is acetylcholine, and with what types of

synapses is it used? How does acetylcholine work?

• A23:• Acetylcholine is a neurotransmitter that

works with cholinergic synapses.• Ach depolarizes the postsynaptic

membrane, causing the creation of another action potential.• Acetylcholinesterase breaks down Ach so it

doesn’t go on depolarizing.• Ach is involved with the parasympathetic

nervous system, meaning it relaxes.

Q24: What is noradrenaline, and with what types of synapses is it used? How

does acetylcholine work?

Q24: What is noradrenaline, and with what types of

synapses is it used? How does noradrenaline work?

• A24:• Noradrenaline is a neurotransmitter that

works with adrenergic synapses.• Noradrenalinealsodepolarizes the

postsynaptic membrane, causing the creation of another action potential.• Noradrenaline is involved with the

sympathetic nervous system, meaning it spazzes you out.

Tier 1, Round 5

Section E.4 (pg. 481 – 489)

Q25: Name some of the ways in which drugs affect the brain.

Q25: Name some of the ways in which drugs affect

the brain.

• A25:• block a receptor for a neurotransmitter• block release of a neurotransmitter• enhance release of a neurotransmitter• mimic a neurotransmitter• block removal of a neurotransmitter

Q26: How do excitatory drugs behave?

Q26: How do excitatory drugs behave?

• A26:• Nicotine mimics acetylcholine, but it cannot

be broken down by acetylcholinesterase, so the effect lingers.• Nicotine causes dopamine to be released.• Cocaine and amphetamine stimulate

transmission at adrenergic synapses and so makes you alert and euphoric.• Cocaine blocks dopamine removal from the

synapse, and amphetamine stops it from being broken down.

Q27: How do inhibitory drugs behave?

Q27: How do inhibitory drugs behave?

• A27:• Benzodiazepine and alcohol increase the binding

of GABA, the main inhibitory neurotransmitter, to the postsynaptic neuron.

• Both drugs cause the postsynaptic neuron to become hyperpolarized, inhibiting further action potentials.

• These drugs produce a feeling of sedation, and somehow alcohol also increases dopamine concentration.

• Tetrahydrocannabinol binds to the same receptors as anandamide and cause hyperpolarization.

Q28: How do THC and cocaine affect mood, synapse and behavior?

Q28: How do THC and cocaine affect mood,

synapse and behavior?

• A28:• THC affects learning, coordination, problem

solving and short-term memory negatively.• Cocaine makes you gabby, alert and

euphoric, and you stop feeling the need to eat and drink. Essentially, it makes you spazzy, so large amounts of it make you behave “erratically” and “violently.”

Q29: Explain the three main factors in addiction: genetic predisposition, social

factors and dopamine secretion.

Q29: Explain the three main factors in addiction: genetic

predisposition, social factors and dopamine secretion.

• A29:• Using twin experiments, scientists have discovered that

if one identical male twin has an addiction, the other twin is 50% more likely to have an addiction as well.

• A deficiency in dopamine receptors also causes an increased susceptibility to addiction.

• If a child is surrounded by drug addicts, he or she is more likely to become a drug addict him or herself.

• Constant stimulation of dopamine receptors causes them to become progressively less responsive to dopamine; in order to get the same sensation desired from a drug, greater and greater quantities must be taken.

Q30: What type of inheritance accounts for wide variation in traits such as eye

and skin color?

Q30: What type of inheritance accounts for wide variation

in traits such as eye and skin color?

• A30:• polygenic inheritance

Tier 2

Lightning Round!

QL1: List the nine steps involved in the mechanism of synaptic transmission.

QL1: List the nine steps involved in the mechanism

of synaptic transmission.

• AL1:1. Calcium ions diffuse into the terminal buttons.2. Vesicles containing neurotransmitter fuse with the plasma membrane and release

the neurotransmitters.3. Neurotransmitter diffuses across the synaptic gap from the presynaptic neuron to

the postsynaptic neuron.4. Neurotransmitter binds with a receptor protein on the postsynaptic neuron

membrane.5. This binding results in an ion channel opening and sodium ions diffusing in through

this channel.6. This initiates the action potential to begin moving down the postsynaptic neuron

because it is depolarized.7. Neurotransmitter is degraded by specific enzymes and is released from the receptor

protein.8. The ion channel closes to sodium ions.9. Neurotransmitter fragments diffuse back across the synaptic gap to be reassembled

in the terminal buttons of the presynaptic neuron.