Intro To The Nervous System

Question 1

Functions of the nervous system

Answer 1

Sensation, integration, action SIA

Question 2

Sensation

Answer 2

Constant monitoring of internal and external environment by receptors that respond to appropriate stimuli

Question 3

Integration

Answer 3

Interpretation and processing of sensory information and decision to act or not

Question 4

Action

Answer 4

Activation or inhibition of effectors

Question 5

Divisions of the nervous system

Answer 5

CNS - brain and spinal cord derived from neural tube,where integration and cognition occur

PNS-cranial and spinal nerves, transmit electrical impulses (action potentials) Afferent signals-from receptors to CNS (sensory) Efferent signals-from CNS to effectors (motor)

Question 6

Neuron types

Answer 6

Bipolar, pseudo-unipolar,multipolar

Question 7

Bipolar neuron

Answer 7

One axon, one dendrite

Special sensory

Question 8

Pseudo-unipolar neuron

Answer 8

Sensory neurons

Single axon (one end in PNS, other in CNS)

PNS-somatic and visceral sensory

Question 9

Multipolar neurons

Answer 9

Motor neurons

Single axon, many dendrites

Common in CNS and brain

Question 10

Nervous system connective tissues

Answer 10

• Endoneurium: covers a single axon (nerve fiber)and its myelin sheath
• Perineuriumi covers a fascicles composed of several axons
• Epineurium:covers multiple fascicles, fatty tissue,and vasculature; forms an anatomical nerve

EPE

Question 11

Nerve cell bodies

Answer 11

Typically clustered together

Nucleus: group of nerve cell bodies in the CNS

Ganglion:group of nerve cell bodies in the PNS

Nelly can’t get past

Question 12

Collection of axons (nerve fibers)

Answer 12

• Tract= collection/bundle of axons in the CNS often connecting nuclei (neighboring or distant)
• Nerves= collection/bundle of axons in the PNS
  
  • E.g. Maxillary nerve or facial nerve
  • other terms: Ramus, root, trunk, division, cord

Question 13

GSA

Answer 13

General Somatic Afferent

Somatosensory

Touch, temperature, pain,and proprioception from the somatic/conscious body

Question 14

GVA

Answer 14

General Visceral afferent

Viscerosensory

Pain, chemo-, baro-,mechano-,sensation from the visceral/internal organs

Question 15

SSA

Answer 15

Special somatic Afferent

Vision, hearing, balance

Question 16

SVA

Answer 16

Special Visceral Afferent

Taste and smell

Question 17

GSE

Answer 17

General Somatic Efferent

Somatomotor

To skeletal muscle: carried by cranial nerves Ill, IV, VI, XIs (11 spinal segment),XII, and Spinal nerves

3, 4, 6, 11, 12

Question 18

GVE

Answer 18

General Visceral Efferent

Visceromotor

To smooth and cardiac muscles: carried by autonomic nerves (sympathetic and parasympathetic)

Question 19

SVE

Answer 19

Special Visceral Efferent

Branchiomotor

To skeletal muscles derived from the branchial arches; carried by cranial nerves V,VII,IX,X,XIc (11 cranial portion)

5, 7, 9, 10, 11

Question 20

Sensory neurons with axons in PNS

Answer 20

Called first order or primary neurons

Cell bodies in dorsal root ganglia

Question 21

Sensation types and receptors

Answer 21

• Mechanoreception:fine/discriminative touch (localization), crude touch, pressure,vibration
• Thermoreception:temperature
• Nocioception:pain
• Proprioception:relative position of body parts and joints
• Photoreception: light
• Barosensation:pressure and touch
• Chemoreception:taste and smell, O2/CO2 receptors

Question 22

Complex sensations

Answer 22

• Peripheral nerves are bundles of neurons and often carry multiple modalities and multiple types of sensation
• Sensory loss can involve multiple pathways (e.g. touch and pain)if the nerve or circulation is compromised

Question 23

Hypoesthesia

Answer 23

Numbness

Question 24

Parasthesia

Answer 24

Pins and needles

Tingling, pricking, or burning sensation

Question 25

Motor (efferent) division Motor neurons with axons in PNS

Answer 25

* Lower motor neurons * Cell bodies in CNS (ventral horn motor neurons) * Somatic (GSE):to skeletal (striated)muscle * Visceral(GVE):to smooth and cardiac muscle * visceral motor:autonomic nervous system * Branchial (SVE): carried only by cranial nerves

Question 26

Autonomic nervous system

Answer 26

* Visceral motor (GVE) * Sympathetic-fight or flight * Parasympathetic-rest and digest * Regulates involuntary bodily functions * Presynaptic neuron * have cell bodies in the CNS * from CNS to ganglion or directly to target organ * Post synaptic neuron * have cell bodies in the ganglion * from ganglion to effector organ

Question 27

Difference between sympathetic and parasympathetic nervous systems

Answer 27

Question 28

Different Actions of Sympathetic and Parasympathetic Nervous System

Answer 28

Question 29

Meningeal Spaces

Answer 29

Question 30

Regions of vertebral column

Answer 30

cervical, thoracic, lumbar, sacral, coccygeal

Question 31

Vertebral foramen

Answer 31

form a longitudinal canal for the passage of the spinal cord

Question 32

Intervertebral foramen

Answer 32

formed by 2 adjacent vertebrae, allow nerves to exit/enter the spinal cord

Question 33

Intervertebral discs | (outer/inner)

Answer 33

Outer annulus fibrosis Inner nucleus pulposis outside, a falcon is preying

Question 34

Meninges

Answer 34

* Protect and support the CNS * Connective tissues: * dura mater (outer layer) * endosteal layer: only found inside skull * meningeal layer: surrounds brain and spinal cord * continuous with epineurium around spinal cord * arachnoid mater * loose, web layer allows flow of cerebral spinal fluid * pia mater * inseperable from surface of spinal cord

Question 35

Spinal cord Extends from? Surrounded by? Ends in? Anchored by?

Answer 35

* extends from foramen magnum to L1-L2 vertebral level * surrounded by meninges (meningeal layer of dura mater, arachnoid mater, and pia mater) * ends in conus medularis * anchored inferiorly by the filium terminale, a fibrous strand of pia mater * spinal roots and nerves form lumbar-coccygeal levels of cord continue as the cauda equina ("horse tail" of nerve roots)

Question 36

Numbering Spinal Nerves

Answer 36

* cervical segments: spinal nerves emerge from the intervertebral foramen above the vertebrae of the same number; C8 nerve emerges below C7 and above T1 * thoracic-coccygeal segments: spinal nerves emerge from the intervertebral foramen below the vertebra of the same number

Question 37

Cross Section of Spinal Cord

Answer 37

* white matter: nerve tracts=myelinated axons * gray matter: cell bodies * dorsal horn: sensory (GSA/GVA) cell bodies * ventral horn: motor (GSE) cell bodies * lateral horn * autonomic (GVE) cell bodies * T1-L2 (sympathetic) spinal levels * S2-S4 (parasympathetic) spinal levels

Question 38

Root

Answer 38

contains either motor or sensory fibers leaving the spinal cord

Question 39

Spinal nerve

Answer 39

contains all neurons- motor and sensory, epaxial and hypaxial

Question 40

Ramus

Answer 40

contains neurons going to epaxial or hypaxial regions

Question 41

dorsal horn + root= ventral horn + root=

Answer 41

sensory motor

Question 42

Dorsal root ganglion

Answer 42

contains cell bodies of sensory neurons part of the PNS (outside of spinal cord) found in or near the intervertebral foramen

Question 43

dorsal ramus= ventral ramus=

Answer 43

motor + sensory to epaxial region motor + sensory to hypaxial region