GROSS ANAT OF THE NERV SYSTEM

Question 1

What are the components of the CNS?

Answer 1

BRAIN: Forebrain (Telencephalon, Diencephalon), Brain Stem (Midbrain, Pons, Medulla), Cerebellum; SPINAL CORD: Cervical, Thoracic, Lumbar, Sacral, Coccygeal

Question 2

What are the components of the PNS?

Answer 2

The nerves that connect your CNS to the rest of your body. Cranial nerves (Origin = brain stem, Exceptions CN I and II); Spinal nerves (Origin = spinal cord)

Question 3

Define afferent signals/information.

Answer 3

Neuronal projections to a neuron, group of neurons or central nervous system.

AFFERENT ARRIVES!

Question 4

Define efferent signals/information.

Answer 4

Neuronal projections from a neuron, group of neurons or central nervous system.

EFFERENT EXITS!

Question 5

What is the difference between the autonomic and somatic nervous systems?

Answer 5

Autonomic (unconscious visceral motor); Somatic (conscious motor and sensory)

Question 6

What are 3 functions of the nervous system?

Answer 6

1. Sensory (afferent) = sensory receptors detect stimuli and transmit information to the brain or spinal cord; 2. Integrative function = interneurons analyze and integrate sensory information; 3. Motor function (efferent) = motor neurons initiate actions in effectors.

Question 7

What is the CNS?

Answer 7

Brain and spinal cord

Question 8

What is a nucleus?

Answer 8

A group of neurons within the CNS with similar function, connectivity, and neurotransmitters

Question 9

What is a tract?

Answer 9

A bundle of axons traveling together within the CNS

Question 10

What is a synapse?

Answer 10

A point of connection/communication between neurons

Question 11

What is afferent?

Answer 11

Arriving information

Question 12

What is efferent?

Answer 12

Exiting information

Question 13

What is the PNS?

Answer 13

Cranial nerves and spinal nerves

Question 14

What is a nerve?

Answer 14

A bundle of axons (plus associated connective tissue and blood vessels) located outside the brain and spinal cord

Question 15

What is a ganglion?

Answer 15

A group of neurons outside of the CNS with similar function, connectivity and neurotransmitters

Question 16

What is the somatic nervous system?

Answer 16

Afferent and efferent systems that regulate motor innervation of skeletal muscle and relay sensory information from the external environment

Question 17

What is the autonomic nervous system?

Answer 17

Efferent systems that regulate motor innervation of smooth muscle and glands

Question 18

What is the visceral sensory system?

Answer 18

Afferent sensory information from the internal environment (hollow organs)

Question 19

What are the components of the somatic nervous system?

Answer 19

Somatic sensory neurons (Afferent) convey information from sensory receptors; Somatic motor neurons (Efferent) convey information from the CNS to skeletal muscles.

Question 20

What are the components of the autonomic nervous system?

Answer 20

Sensory neurons (Afferent) convey information from visceral organs; Autonomic motor neurons (Efferent) convey information from the CNS to smooth muscle, cardiac muscle, and glands.

Question 21

How are neurons classified?

Answer 21

Nervous tissue is comprised of neurons and neuroglia. Neurons are excitable, postmitotic, and highly variable; Neuroglia support, nourish, and protect neurons.

Question 22

What are the important characteristics of neurons?

Answer 22

Neurons are highly specialized cells with organelles. Key components include cell body/soma, Nissl bodies, dendrites, axons, and terminal boutons.

Question 23

What is the function of an axon?

Answer 23

The axon carries electrical impulses away from the neuron’s cell body and toward other neurons, muscles, or glands.

Question 24

What is the function of a dendrite?

Answer 24

Dendrites receive electrical or chemical signals from other neurons.

Question 25

What are the 3 types of neurons in vertebrates?

Answer 25

1. Multipolar = 1 axon, many dendrites; 2. Bipolar = 1 axon and 1 main dendrite; 3. Pseudo-unipolar = 1 process exits the soma and splits.

Question 26

What are the components of a synapse?

Answer 26

1. Electro-chemical impulse travels along axon; 2. Presynaptic neuron releases neurotransmitters; 3. Neurotransmitters bind to receptors on postsynaptic neuron; 4. Electro-chemical impulse continues.

Question 27

What are the 4 types of glia found in the CNS?

Answer 27

1. Astrocytes = contact capillaries and neurons; 2. Oligodendrocytes = myelinate axons; 3. Microglia = phagocytes; 4. Ependymal Cells = line ventricles and produce CSF.

Question 28

What are the 2 types of glia found in the PNS?

Answer 28

1. Schwann cells = myelinating cells; 2. Satellite cells = surround neuron cell bodies and support.

Question 29

What cells are responsible for myelination in the CNS?

Answer 29

Oligodendrocytes

Question 30

What cells are responsible for myelination in the PNS?

Answer 30

Schwann Cells

Question 31

What cell type lines the ventricles?

Answer 31

Ependymal cells

Question 32

Which cells migrate into the CNS and are not derived from the neural crest or neural tube?

Answer 32

Microglia

Question 33

What cell types form the blood-brain barrier?

Answer 33

Astrocytes

Question 34

What is the main component of gray matter?

Answer 34

Gray matter contains neurons and their proximal dendrites (no myelin)

Question 35

What is the main component of white matter?

Answer 35

White matter contains myelinated axons and myelinating oligodendroglia.

Question 36

What is a synapse?

Answer 36

A site of communication between two neurons.

Question 37

What is a sulcus?

Answer 37

A groove in the brain.

Question 38

What is a gyrus?

Answer 38

A bump in the brain.

Question 39

How many lobes make up the cerebral cortex?

Answer 39

Frontal, Parietal, Occipital, Temporal, Limbic, Insula

Question 40

What are the anatomical landmarks that separate the different cortical lobes?

Answer 40

Parieto-occipital sulcus, central sulcus, lateral fissure.

Question 41

What is the anatomical landmark that separates the cerebral hemispheres?

Answer 41

The superior sagittal sulcus.

Question 42

What are the 3 meningeal layers, superficial to deep?

Answer 42

Dura mater, Arachnoid mater, Pia mater

Question 43

What creates cerebrospinal fluid, and where is it found?

Answer 43

Choroid plexus in the lateral ventricles.

Question 44

What absorbs cerebrospinal fluid, and where is it found?

Answer 44

Arachnoid granulations in the arachnoid mater.

Question 45

What are the functions of the meningeal layers?

Answer 45

Dura mater = tough protection; Arachnoid mater = CSF circulation; Pia mater = follows brain surface.

Question 46

What subdivisions of the lateral ventricle are associated with the lobes?

Answer 46

Frontal - anterior horn; Temporal - inferior horn; Occipital - posterior horn; Parietal - body.

Question 47

Which ventricle is found within the diencephalon?

Answer 47

Third ventricle.

Question 48

Which ventricle is found within the brain stem?

Answer 48

Fourth ventricle.

Question 49

What is the path of cerebrospinal fluid through and out of the ventricles?

Answer 49

Choroid Plexus secretes CSF into ventricles, drains to subarachnoid space, circulates, and is absorbed by arachnoid granulations.

Question 50

What two arteries are the main contributions to the cerebral vascular circle?

Answer 50

Internal carotid (anterior areas) and Vertebral (posterior areas).

Question 51

What larger artery is the source of these arteries?

Answer 51

Internal carotid branches from common carotid; Vertebral branches from subclavian.

Question 52

What are the 3 main branches of the cerebral vascular circle?

Answer 52

Anterior cerebral (ACA), middle cerebral (MCA), posterior cerebral (PCA).

Question 53

From which artery does the right subclavian branch?

Answer 53

The right subclavian branches from the brachiocephalic artery.

Question 54

From which artery does the brachiocephalic branch?

Answer 54

The brachiocephalic branches from the aortic arch.

Question 55

From which artery does the left subclavian branch?

Answer 55

The left subclavian branches from the aortic arch.

Question 56

What are the three main branches of the cerebral vascular circle?

Answer 56

1. Anterior cerebral (ACA) - supplies the medial aspect of the frontal & parietal lobes. 2. Middle cerebral (MCA) - supplies the lateral aspect of the frontal, parietal, & temporal lobes. 3. Posterior cerebral (PCA) - supplies the medial & lateral aspects of the occipital lobe & a portion of the medial aspect of the temporal lobe.

Question 57

From what germ layer does the nervous system arise?

Answer 57

The nervous system arises from the ectoderm.

Question 58

What mesodermal structure induces the neural plate?

Answer 58

The notochord induces the neural plate.

Question 59

What happens if the anterior neuropore fails to close?

Answer 59

Failure of the anterior neuropore to close results in anencephaly.

Question 60

What happens if the posterior neuropore fails to close?

Answer 60

Failure of the posterior neuropore to close results in spina bifida.

Question 61

What forms the ventricular system?

Answer 61

The ventricular system forms from the lumen within the neural tube.

Question 62

Why are there two lateral ventricles?

Answer 62

The two lateral ventricles form from the developing hemispheres of the brain.

Question 63

Where is the neural crest formed?

Answer 63

The neural crest is formed as it separates from the neural tube.

Question 64

What types of cells does the neural crest become?

Answer 64

The neural crest becomes: - Dorsal root ganglia neurons - Autonomic ganglia neurons - Pia mater (meninges) - Schwann cells (peripheral nerves) - Satellite cells (peripheral ganglia) - Melanocytes (skin)