Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

LSB142 Anatomy and Physiology > CNS > Flashcards

CNS Flashcards

1
Q

Functions of the nervous system

A
  1. Sensory input – gathering information
    Sensory Receptors monitor changes, called stimuli
  2. Integration – Processes and interprets sensory input
  3. Motor output – a response or effect, activates muscles or glands
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Organisation of the nervous system

A
  1. Structures (structural classification)

2. Activities (functional classification)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Two structural classfications of the nervous system are?

A
  1. Central Nervous System (CNS)

2. Peripheral Nervous System (PNS)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Organs and functions of CNS

A

Organs – Brain and spinal cord
Functions - ▪ Integration; command center
▪ Interprets incoming sensory information
▪ Issues outgoing instructions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Organs and functions of PNS

A

Nerves extending from the brain and spinal cord
Spinal nerves – carry impulses to and from the spinal cord
Cranial Nerves – Carry impulses to and from the brain
Functions – Serve as communication lines among sensory organs, the brain and spinal cord and glands or muscles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Functional classifications of PNS

A
  1. Sensory – sense organs

2. Motor – somatic/voluntary (skeletal muscles) and autonomic/involuntary (cardiac and smooth muscle)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

2 principal Nervous tissue cell types

A 
Neurons
Supporting cells (Neuroglia)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What are the four types of Glial cells

A

Astrocytes
Microglial
Ependymal
Oligodendrocytes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Explain features of Astrocytes

A
  • Most abundant and versatile neuroglia
  • Positioned between neurons and capillary
  • Link nutrient supply in capillaries to neurons and control chemical environment from any harmful substances in the blood.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Explain features of Microglial Cells

A

Spider like phagocytes that monitor the health of nearby neurons and remove debris like dead bone cells and bacteria

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Explain features of Ependymal cells

A

Line the central cavities of the brain and spinal cord. The cilia maintains cerebrospinal fluid which fills the cavities and forms a watery cushion.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Explain features of Oligodendrocytes cells

A

▪ Wrap around nerve fibers in the central nervous system

▪ Produce myelin sheaths

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Major regions of the Neuron

A
  • Cell body -nucleus and metabolic centre of the cell

- Processes – fibres that extend from the cell body

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Components of neuron cell body

A

▪ Cell body is the metabolic center of the neuron
▪ Nucleus with large nucleolus
▪ Nissl bodies
Rough endoplasmic reticulum
▪ Neurofibrils
Intermediate filaments that maintain cell shape

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Components of the neuron processes

A

Dendrites – conduct impulses toward the cell body (100s)
Axons—conduct impulses away from the cell body ▪ End in axon terminals, which contain vesicles with neurotransmitters
Axon hillock – where axons start
Synaptic cleft—gap between axon terminals and the next neuron
Synapse—functional junction between nerves where a nerve impulse is transmitted

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is Myelin

A

White, fatty material covering axons ▪ Protects and insulates fibers ▪ Speeds nerve impulse transmission

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is myelin sheaths

A

Oligodendrocytes—produce myelin sheaths around axons of the CNS ▪ Lack a neurilemma

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What are the 3 functional classifications of neurons?

A
  1. Sensory Afferent neurons
  2. Motor efferent neurons
  3. interneurons
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What are the 3 structural classification of neurons and there features?

A

Multipolar neurons—many extensions from the cell body ▪ All motor and interneurons are multipolar ▪ Most common structural type
Bipolar neurons—one axon and one dendrite ▪ Located in special sense organs, such as nose and eye ▪ Rare in adults
Unipolar neurons—have a short single process leaving the cell body ▪ Sensory neurons found in PNS ganglia ▪ Conduct impulses both toward and away from the cell body

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Describe actions of a sensory neuron

A

▪ Carry impulses from the sensory receptors to the CNS. Cell body is located in ganglion
▪ Receptors include: Dendrites have specific receptors that sense changes nearby ▪ Cutaneous sense organs in skin ▪ Proprioceptors in muscles and tendons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Describe actions of a motor neuron

A

Carry impulses from the central nervous system to viscera and/or muscles and glands. Cell bodies found within the central nervous system

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Describe actions of an Interneurons

A

Cell bodies located in the CNS ▪ Connect sensory and motor neurons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Action Potential Steps

A
  1. The plasma membrane at rest is inactive (polarized- -70 mV). Fewer positive inside than outside. As long as the inside of the membrane is more negative (fewer positive ions) than the outside, the cell remains inactive
  2. Action potential = nerve impulse. ▪ A graded potential (localized depolarization) exists where the inside of the membrane is more positive and the outside is less positive ▪ If the stimulus is strong enough and sodium influx great enough, local depolarization activates the neuron to conduct an action potential (nerve impulse)
  3. ▪ If enough sodium enters the cell, the action potential (nerve impulse) starts and is propagated over the entire axon ▪ All-or-none response means the nerve impulse either is propagated or is not ▪ Fibers with myelin sheaths conduct nerve impulses more quickly. Reaches 30mV
  4. ▪ Membrane permeability changes again—becoming impermeable to sodium ions and permeable to potassium ions ▪ Potassium ions rapidly diffuse out of the neuron, repolarizing the membrane ▪ Repolarization involves restoring the inside of the membrane to a negative charge and the outer surface to a positive charge. Less than -70mV. hyperpolerization
  5. ▪ Initial conditions of sodium and potassium ions are restored using the sodium-potassium pump ▪ This pump, using ATP, restores the original configuration ▪ Three sodium ions are ejected from the cell while two potassium ions are returned to the cell ▪ Until repolarization is complete, a neuron cannot conduct another nerve impulse. Goes back to -70 mV
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What is reflex and a reflex arc?

A

Rapid, predictable and involuntary responses to stimuli

Occur over neural pathways called reflex arcs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

2 types of Reflex arcs

A

Somatic Reflexes

Automatic Reflexes

26
Q

Explain Somatic Reflexes

A

All reflexes that stimulate the skeletal muscles
Involuntary, although skeletal muscle is under voluntary control.
E.G. Pulling your hand away from a hot object

27
Q

Explain Automatic Reflexes

A

Regulate the activity of smooth muscles, the heart and glands
E.G. Regulation of smooth muscles, heart and blood pressure, glands, digestive system

28
Q

5 elements of Reflex arc

A

Sensory receptor – reacts to a stimulus
Sensory neuron – carries message to the integration center
Integration center (CNS) – processes information an directs motor output
Motor neuron – carries messages to an effector
Effector organ – is the muscle or gland to be stimulated

29
Q

Difference between two-neuron and three neuron reflex arcs

A

Three neuron arcs are more complicated and has an interneuron

30
Q

4 main regions of the brain

A

Cerebral Hemispheres
Diencephalon
Brain Stem
Cerebellum

31
Q

Explain features of the cerebral hemisphere and the three main regions

A

Left and right superior parts of the brain
More than half the brain mass
Surface is made of ridges Gyri
Grooves called Sulci
Fissures are deeper grooves
Lobes are named for the cranial bones that lie over them
3 main regions are: 1. Cortex is superficial gray matter (fresh brain tissue) 2. White matter 3. Basal nuclei are deep pockets of gray matter

32
Q

Cerebral Areas involved in special senses

A 
Visual area (occipital lobe)
Auditory Area (temporal lobe)
Olfactory area (temporal lobe)
33
Q

Describe the primary somatic sensory area

A

▪ Located in parietal lobe posterior to central sulcus
▪ Receives impulses from the body’s sensory receptors
▪ Pain, temperature, light touch (except for special senses)
▪ Sensory homunculus is a spatial map
▪ Left side of the primary somatic sensory area receives impulses from right side (and vice versa)

34
Q

Describe the primary motor area

A

▪ Located anterior to the central sulcus in the frontal lobe
▪ Allows us to consciously move skeletal muscles
▪ Motor neurons form pyramidal (corticospinal) tract, which descends to spinal cord
▪ Motor homunculus is a spatial map

35
Q

What is Broca’s area?

A

Part of the Cerebral Cortex

▪ Involved in our ability to speak ▪ Usually in left hemisphere

36
Q

3 Specialized areas of the Cerebral Cortex

A

▪ Anterior association area (frontal lobe) ▪ Posterior association area (posterior cortex) ▪ Speech area (for sounding out words)

37
Q

Name of the lobes

A

Frontal
Parietal
Occipital
Temporal

38
Q

Describe cerebral white matter

A

▪ Composed of fiber tracts deep to the gray matter
▪ Corpus callosum connects hemispheres
▪ Tracts, such as the corpus callosum, are known as commissures
▪ Association fiber tracts connect areas within a hemisphere
▪ Projection fiber tracts connect the cerebrum with lower CNS centers

39
Q

What is basal nuclei

A

▪ “Islands” of gray matter buried deep within the white matter of the cerebrum ▪ Regulate voluntary motor activities by modifying instructions sent to skeletal muscles by the primary motor cortex

40
Q

What is the diencephalon and components of it?

A

▪ Sits on top of the brain stem
▪ Enclosed by the cerebral hemispheres
▪ Made of three structures 1. Thalamus 2. Hypothalamus 3. Epithalamus

41
Q

What is the thalamus

A

▪ Encloses the third ventricle ▪ Relay station for sensory impulses passing upward to the cerebral cortex ▪ Transfers impulses to the correct part of the cortex for localization and interpretation

42
Q

What is the hypothalamus

A

▪ Makes up the floor of the diencephalon
▪ Important autonomic nervous system center ▪ Regulates body temperature ▪ Regulates water balance ▪ Regulates metabolism
▪ Houses the limbic center for emotions
▪ Regulates the nearby pituitary gland
▪ Houses mammillary bodies for olfaction (smell)

43
Q

What is the epithalamus

A

▪ Forms the roof of the third ventricle
▪ Houses the pineal body (an endocrine gland)
▪ Includes the choroid plexus—forms cerebrospinal fluid

44
Q

What is the brain stem

A

▪ Attaches to the spinal cord
▪ Parts of the brain stem
1. Midbrain 2. Pons 3. Medulla oblongata

45
Q

Describe the midbrain

A

▪ Extends from the mammillary bodies to the pons inferiorly
▪ Cerebral aqueduct (tiny canal) connects the third and fourth ventricles
▪ Two bulging fiber tracts, cerebral peduncles, convey ascending and descending impulses
▪ Four rounded protrusions, corpora quadrigemina, are visual and auditory reflex centers

46
Q

Describe pons

A

▪ The rounded structure protruding just below the midbrain ▪ Mostly composed of fiber tracts ▪ Includes nuclei involved in the control of breathing

47
Q

Describe medulla oblongata

A

▪ The most inferior part of the brain stem that merges into the spinal cord ▪ Includes important fiber tracts
▪ Contains important centers that control: ▪ Heart rate ▪ Blood pressure ▪ Breathing ▪ Swallowing ▪ Vomiting

48
Q

What is reticular formation

A

▪ Diffuse mass of gray matter along the brain stem ▪ Involved in motor control of visceral organs ▪ Reticular activating system (RAS) ▪ Plays a role in awake/sleep cycles and consciousness ▪ Filter for incoming sensory information

49
Q

What is the cerebellum

A

2 hemispheres with convulated surface
Outer cortex of gray matter and inner region of white matter
Controls balance
Provides precise timing for skeletal muscle activity and coordination of body movements
Fibres reach the cerebellum from the equilibrium apparatus from the inner ear, the eye and skeletal muscles.
Sends messages to body for smooth and coordinated actions
Movement becomes disorganised and clumsy if this part is damaged

50
Q

Protection of the CNS

A

▪ Meninges ▪ Cerebrospinal fluid (CSF) ▪ Blood-brain barrier

51
Q

Components of the Meninges

A

Dura mater
Arachnoid Space
Pia mater

52
Q

Explain the Cerebrospinal fluid

A

▪ Similar to blood plasma in composition
▪ Formed continually by the choroid plexuses
▪ Choroid plexuses—capillaries in the ventricles of the brain
▪ CSF forms a watery cushion to protect the brain and spinal cord
▪ Circulated in the arachnoid space, ventricles, and central canal of the spinal cord

53
Q

Steps of the cerebrospinal fluid circulation

A
  1. CSF is produced by the choroid plexus of each ventricle
  2. CSF flows through the ventricles and into the subarachnoid space via the median and lateral apertures. Some CSF flows through the central canal of the spinal cord
  3. CSF flows through the subarachnoid space
  4. CSF is absorbed into the dural venous sinuses via the arachnoid villi
54
Q

Features of the blood brain Barrier

A

▪ Includes the least permeable capillaries of the body
▪ Allows water, glucose, and amino acids to pass through the capillary walls
▪ Excludes many potentially harmful substances from entering the brain, such as wastes
▪ Useless as a barrier against some substances (fats, respiratory gases). Blood born alcohol, nicotine impact brain.

55
Q

Name 5 traumatic brain injuries

A
  1. Concussion – Slight brain injury, little perm. Damage
  2. Contusion – marked nervous tissue destruction occurs, coma may occur
  3. Death may occur due to head blows: Intracranial haemorrhage, Cerebral Edema
  4. Cerebrovascular accident (CVA) or stroke
    ▪ Results when blood circulation to a brain area is blocked and brain tissue dies
    ▪ Loss of some functions or death may result ▪ Hemiplegia—one-sided paralysis ▪ Aphasia—damage to speech center in left hemisphere
  5. Transient Ischemic Attack (TIA)
    ▪ Temporary brain ischemia (restriction of blood flow) ▪ Numbness, temporary paralysis, impaired speech
    May be warning for a more serious issue
56
Q

How many pairs of spinal nerves come from spinal cord

A

31, provide two way conduction pathway to brain

57
Q

Grey matter of spinal cord

A

▪ Internal gray matter is mostly cell bodies
▪ Dorsal (posterior) horns house interneurons
▪ Receive information from sensory neurons in the dorsal root; cell bodies housed in dorsal root ganglion
▪ Anterior (ventral) horns house motor neurons of the somatic (voluntary) nervous system
▪ Send information out ventral root ▪ Gray matter surrounds the central canal, which is filled with cerebrospinal fluid

58
Q

White matter of spinal cord

A

▪ Composed of myelinated fiber tracts
▪ Three regions: dorsal (ascending), lateral (ascending and descending), ventral columns (ascending and descendimg) ▪ Sensory (afferent) ascending tracts conduct impulses toward brain
▪ Motor (efferent) descending tracts carry impulses from brain to skeletal muscles

59
Q

Describe the Dura Matter

A

▪ Outermost leathery layer
▪ Double-layered external covering ▪ Periosteum—attached to inner surface of the skull ▪ Meningeal layer—outer covering of the brain
▪ Folds inward in several areas ▪ Falx cerebri ▪ Tentorium cerebelli

60
Q

Describe the Pia Matter

A

Internal layer ▪ Clings to the surface of the brain and spinal cord

61
Q

Describe the Arachnoid Layer

A

▪ Middle layer ▪ Weblike extensions span the subarachnoid space to attach it to the pia mater ▪ Subarachnoid space is filled with cerebrospinal fluid ▪ Arachnoid granulations protrude through the dura mater and absorb cerebrospinal fluid into venous blood

62
Q

What are some receptors?

A
  1. Free nerve endings (pain and temperature receptors)
  2. Meissner’s corpuscle (touch receptor)
  3. Lamellar Corpuscle (Deep pressure receptor)
  4. Golgi tendon organ and muscle spindle (proprioceptor)

LSB142 Anatomy and Physiology (15 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions