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Flashcards in Exam 2 Deck (49):
1

The _______ is the first place on a neuron that fires an action potential.

Axon hillock

2

The resting membrane potential of cells:

Is maintained by the sodium potassium pump

3

If a cell became permeable to sodium

The cell would depolarize

4

Graded potentials

can sum temporally or spatially.
can be excitatory.
can be inhibitory
cause action potentials

5



The opening of which of the following channels would cause an inhibitory graded potential?

Ligand gated potassium channel

6

The rising or depolarization phase of an action potential is due to

Opening of voltage gated sodium channels

7

The falling or depolarization phase of an action potential is due to

Opening of voltage gated potassium channels

Closing of voltage gated sodium channels

8

The absolute refractory period of an action potential:

spans all of the depolarization phase and most of the repolarization phase.

is the period in which a second action cannot be fired.

is the period in which the sodium channels are either open or inactivated.

causes the unidirectional flow of action potentials.

9

During the relative refractory period it is harder to fire another action potential because _________.

Voltage gated potassium channels are open and the membrane is hyperpolarized

10

Unmyelinated axons:

Have action potentials spread down the axon by contiguous conduction

11

Electrical synapses:


are much less common than chemical synapses.

transfer messages faster than chemical synapses.

are formed when two neurons are connected by gap junctions.

are bidirectional.

12



Order the following events that occur at the synapse from first to last. 1 - calcium triggers exocytosis of neurotransmitter from the presynaptic neuron 2 - neurotransmitter diffuses across the synapse and binds to a receptor on the postsynaptic cell 3 - an action potential reaches the axon terminal of the presynaptic cell 4 - neurotransmitter is removed from the synapse to terminate the response 5 - voltage gated calcium channels open on the axon terminal of the presynaptic cell 6 - the postsynaptic cell responds

3,5,1,2,6,4

13



At an excitatory synapse, neurotransmitter released from the presynaptic neuron may cause the __________.

Depolarizer of the postsynaptic cell

14

What type of glial cells myelinated efferent and afferent neurons

Schwann cells

15

Which of the following is the correct order of the meninges, from bone to neural tissue?

Dura mater : arachnoid mater : pia mater

16

In order for ions like sodium, potassium and calcium to move across the capillary endothelial cells of the blood-brain barrier, they must ________.

Be transported across endothelial cells

17

The brain uses 20% of the oxygen we take in during rest because:

It is continuously active

It cannot do anaerobic glycolysis

It can only aerobically metabolize glucose

ALL OF THESE ARE CORRECT

18

The ________ is the region of the brain that controls heart and blood vessel function, respiration, and many digestive functions.

Brainstem

19



The ________ is the region of the brain involved in the control of subconscious coordination of learned motor tasks like walking.

Cerebellum

20



The ________ is a region of the diencephalon that filters and refines sensory information, allowing us to direct our attention to specific external stimuli

Thalamus

21



The ________ is a region of the diencephalon that provides an important link between the endocrine and nervous system.

Hypothalamus

22



The ______ is a region of the cerebrum that selects and maintains purposeful motor activity while suppressing useless or unwanted patterns of movement. This area of the brain is damaged in Parkinson's disease.

Basal nuclei

23



Which of the following characteristics is NOT a specialization of the right side of the cerebrum in most individuals

Logic

24

The ______ contains the visual cortex because visual information is processed there

Occipital lobe

25



The _______ localizes the source of sensory input from the skin and perceives the level of intensity of the stimulus.

Primary somatosensory cortex

26



A reading disability like dislexia is due to a problem in _________ that governs language comprehension.

Wernicke’s area

27

Sensory neurons often act as the _____ in basic reflexes.

Afferent pathway

28

The knee jerk reflex is an example of a _________ reflex

Stretch

29

Which of the following physiological responses would be associated with elevated sympathetic nervous system activity?

Increased contractile force of the heart

30

Which of the following endocrine glands is innervated by sympathetic preganglionic neurons and releases epinephrine and norepinephrine into the bloodstream when stimulated?

Adrenal medulla

31



The sympathetic nervous system has ________ preganglionic neurons and _______ postganglionic neurons.

Short : long

32

Parasympathetic preganglionic neurons release the neurotransmitter ________; sympathetic postganglionic neurons release the neurotransmitter ________.

Acetylcholine : norepinephrine

33

With respect to their innervation, individual skeletal muscle fibers (cells) are innervated by:

A single motor neuron

34



The steps of synaptic transmission at the neuromuscular junction are listed below, out of order. Choose the correct order. 1 - Acetylcholine binds to receptors on the motor end plate. 2 - Acetylcholine is released by exocytosis from the motor neuron. 3 - An action potential is produced on the muscle fibers sarcolemma. 4 - Voltage-gated calcium channels on the motor neurons plasma membrane open. 5 - An action potential arrives at the motor neurons axon terminal.

54213

35



Which of the following types of receptors would the body use to detect overall solute levels in blood?

Osmoreceptors

36



Which of the following statements concerning receptors is correct?

Tonic receptors are important in situations where maintained information about a stimulus is valuable.

37



Which of the following statements about sensory coding is TRUE?

Coding for a stimulus type is maintained from receptor to cortex.

The intensity of stimulus is coded for by the frequency of the action potential.

The location of the stimulus is coded for by the receptive field activated.


The type of stimulus is coded for by the specific pathway activated.


All of the above are true.

38



Sensory receptors that respond to tissue-damaging stimuli or stimuli that have the potential to damage tissue are called ________.

Nociceptors

39

Which is a characteristic of fast pain?

Impulses carried along myelinated fibers

40

Pain signals from visceral receptors are 'referred' to the body surface by ________.

The convergence of visceral and somatic afferent neurons on the same second-order neurons

41


The radial muscles of the iris are innervated by the ________ nervous system and their contraction causes pupillary ________.

Sympathetic: dilation

42

When the ciliary muscles of the eye are contracted, the zonular fibers are _____ and the lens is relatively ________, allowing the eye to focus on objects that are ________.

Slack : round : close

43

Cones:

Have High acuity

44



When we enter a dark room, the retinal and opsin molecules within the ________ must first ________ before low light levels can be detected.

Rods : associate

45

What type of sensory receptor detects sound waves in the cochlea?

Mechanoreceptor

46

Amplitude or loudness of sound is coded for by ________.

The degree of deflection of the stereocilia on the hair cells stimulated.

47

Whether the hair cells in the semicircular canal are depolarized or hyperpolarized is dependent upon the ________.

Direction the stereocilia on the hair cells are bent

48



Which taste is perceived when sodium ions in food or drink enter through channels on taste receptor cells?

Salty

49

Olfactory receptors:

Are specialized endings on afferent neurons.

detect thousands of types of odorants.

only detect chemicals that are volatile.

send excitatory messages to the olfactory bulb when a specific odorant binds to a receptor.

ALL OF THE ABOVE ARE CORRECT