Unit 9 Nervous System Flashcards
What are the differences between the central nervous system and peripheral nervous system?
CNS - is composed of the brain and the spinal cord
PNS - is everything outside of the CNS
Describe the structure of the Neuron
Neuron structire is suited to their role as conducting cells
The soma/cell body has the most cytoplasm, the organelles and the nucleus
Dendrites branch off the cell body and appear as thing extensions
A long axon extends from the cell body
Differences in CNS and PNS when it comes to cell bodies and axons?
group of neuron cell bodies/Bundles of Axons
CNS = Nucleus / Tract
PNS = Ganglion / Nerve
Name the two divisions of the CNS and their functions
Somatic Nervous System controls conscious perception and voluntary motor response
Autonomic nervous system is responsible for involuntary control. ie homeostasis
What is the enteric nervous system?
is responsible for controlling the smooth muscle and glandular tissue in your digestive system.
- large part of the PNS
Glial cells within CNS/PNS and their basic function?
CNS PNS Function
Astrocytes satellite cell Support
Oligodendrocyte schwann cell / isolation, myelinations
Microglia // immune surveillance,
Ependymal Cell //creating cerebrospinal fluid
What is Myelin?
Myelin acts as insulation for axons provided by glial cells creating myelin sheath
Oligodendrocytes in the CNS
Schwann cells in the PNS
What are the 4 major regions of the brain?
- cerebrum
- diencephalon
- brain stem
- cerebellum
What neurological functions is the cerebrum responsible for?
- memory, emotion, and consciousness
What is the gyrus and sulcus?
Gyrus - the ridge of one of those wrinkles
Sulcus - is the groove between two gyri
The diencephalon is composed of what two major regions?
Thalmus - process and relay information between cerebral cortex and the PNS, spinal cord, or brain
Hypothalmus - inferior and slightly anterior to the thalamus , involved in regulating homeostasis, being in charge of the ANS and the endocrine system
Name 3 regions of the Brain Stem and their functions?
Midbrain Pons - sensory information about visual space, auditory space and somatosensory space
Hindbrain (Medulla oblongata) - controls the rate and force of heart contraction, the diameter of blood vessels and the rate of and depth of breathing
What is the function of the cerebellum?
- integrates motor commands from the cerebral cortex with sensory feedback from the PNS
- allows for coordination and precise execution of motor activities
Name 4 spinal cord regions
Cervical, thoracic, lumbar, sacral regions
Name the 3 different horns of the spinal cord and their functions
Posterior Horn - responsible for sensory processing
Anterior horn - sends out motor signals to the skeletal muscles
lateral horn - only found in the thoracic and upper lumbar and sacral regions, is the central component of the sympathetic division of the Autonomic nervous system (ANS)
What carries sensory information to the brain? carries motor commands from the brain?
Ascending tracts
descending tracts
What is the meninges and their function?
- covers the outer surface of the CNS
- protects the brain
- broken into the dura mater, arachnoid mater, pia mater
List layers of meninges from deepest to most superficial
Cerebral Cortex -> (deepest) Pia Mater -> (Meninges) subarachnoid space -> Arachnoid Mater -> (Meninges) Subdural Space -> Dura Mater -> (Meninges) Bone -> (most superficial)
What is dura mater? arachnoid mater? pia mater?
Dura mater - protective sheath over the entire brain and spinal cord
arachnoid mater - thin fibrous tissue that forms a loose sac around the CNS
Pia mater - thin fibrous membrane that follows the down the cerebral cortex
What is cerbrospinal fluid (CSF)?
- circulates throughout and around the CNS
- acts as a liquid cushion
- circulates to remove metabolic wastes from the interstitial fluid
What are the 12 pairs of cranial nerves and their functions? type of nerve?
- olfactory - smell // sensory
- optic - vision // sensory
- ocular motor - eye movement and pupil relfex // motor
- trochlear - eye movement // motor
- trigeminal - face sensation and chewing // mixed
- abducens - movement of eye side to side // mixed
- facial - taste and movement of facial muscles // mixed
- vestibulocochlear - hearing and balance // mixed
- glossopharyngeal - throat sensation, taste+swollowing // mixed
- Vagus - taste, control of larynx and pharynx // mixed
- accessory - neck movement // motor
- hypoglossal - movement of tongue // motor
The spinal nerves are split into regions, what are they?
Cervical nerves c1-c8 thoracic nerves T1-T12 Lumbar nerves L1-L3 Sacral nerves S1-S5 coccygeal nerve C0
What is the Somatic Nervous System?
- responsible for conscious perception of the environment and voluntary responses to that perception by skeletal muscles
Describe an example of a stretch reflex
- quad muscles stretches and stimulate sensory neurons to generate a nerve impulse (action potential)
- impulse travels to the spinal cord where a motor neuron is stimulated
- the motor neuron sends an impulse along the axon to the quad, causing its contraction and the leg to kick
What is a withdrawal reflex?
- is a response generated to a painful stimulus
ie. ) touching something hot
provide an example of withdrawal reflex
- sensory receptors in the skin sense extreme temperature, generating a nerve impulse (action potential)
- impulse is sent to spinal cord through dorsal root ganglion, where a motor neuron is stimulated
- motor neuron sends an impulse to skeletal muscle, causing contraction and removal of the body part of temp.
The autonomic nervous system has two divisions what are they and their functions?
Sympatheic division - fight our flight
parasympathetic - rest and digest
The sodium/potassium pump moves which into and out of a cell?
moves sodium ions out (Na+)
moves potassium ions into cell (K+)
- requires ATP
What are the types of channels/gates?
- ligand-gated, mechanically gated, voltage-gated, and leakage channels
What is membrane potential?
- is a potential of distribution of charge across the cell membrane in millivolts (mV)
- the inside of the cell is compared to the outside
- this distribution of ions causes a measure difference of -70mV called the resting membrane potential
Desrcibe action potential generation
- Na+ opens, rushes into cell driven by concentration gradient
- this causes the inside of the cell to become less negative (depolarization)
- membrane potential reaches +30mV
- K+ channels open up, K+ starts to leave the cell; taking its positive charge with it (repolarization)
- membrane voltage goes back to -70mV but actually overshoots
- brief hyper polarization occurs, K+ channels are slightly delayed in closing
When does the Wigan gated Na+ channel open? mechanically gated? voltage gated?
- open due to neurotransmitter binding
- open when a physical stimulus affects a sensory receptor
- opens once potential has risen to -55mV
Name the 4 Major categories of neurotransmitter systems. Provide brief description and example
Amino Acids - are the single molecule building blocks of proteins // glycine
Biogenic Amines - are enzymatically made from amino acids // dopamine
Cholingereric system - based on the neurotransmitter acetylcholine // acetylcholine
Neuropeptides - molecules made up of chains of amino acids connected by peptide bonds // beta-endorphin
