Lab 7 Flashcards
Central nervous system
The brain and spinal cord that interpret incoming sensory information and issue order
The peripheral nervous system
Cranial and spinal nerves. Ganglia, and sensory receptors which serve as communication lines to carry impulses to the CNs and from the cns
Two divisions of peripheral nervous system
Sensory (afferent)- nerve fibbers that conduct impulses toward the cns
Motor (efferent)- conducts impulses alway from
The cns
Two divisions of motor
Somatic- voluntary- skeletal muscles
Autonomic nervous system - involuntary, smooth muscle, cardiac and glands
Division of ANS
Sympathetic. - fight or flight
Parasympathetic - wine and dine
Gyri
The ridges of the brain
Sulci
The shallow grooves between the ridges on the brain and grooves in the spinal cord
Fissure
Deeper groove
Ganglia
A group of nerve cell bodies in the PNS that receueve and transmit nerve impulses between the peripheral and central
Nuclei
Cluster of nerve cells bodies in the CNS
White matter
Composed of nerve axons, or tracts, with their myelin sheets
Gray matter
Composed of nerve cell bodies and dendrites
Neuron IDs
Dendrite
Axon
Cell body
Myelin sheath
Nodes of ranvier
Presynaptic terminals
Nissl body
Elaborate type of broken up endoplasmix reticulum within the soma
Neuron
Major nervous tissue cells and the only one that carries action potentials
Neuroglial cells
Support the neutrons in some manner
Astrocytes
Ependymal cells
Microglia
Oligodendrocytes
Schwann cells
Astrocytes
Star shaped cells that wrap around and cover blood vessels and neurons- primarily responsible for forming the blood brain barrier
Ependymal cells
Line the ventricles in the brain and are responsible for producing CSF (cerebrospinal fluid)
Microglia
Involved in immune response. These respond to inflammation and phagocytize necrotic tissue and microorganisms
Oligodendrocytes
Wrap around axons of neurons to form the myelin sheath in the CNS
Can wrap around more axons at a time
Schwann cells
Wrap around axons of neurons to form the myelin sheath in the peripheral nervous system
Spinal cord
An extension of the brain stem in association with communication mostly involved with reflexes and transfer information up pathways to the brain and down to leave the CNS
Conus medullaris
Structure that the spinal cord ends up in. L1 or L2
Filum terminale
A string of pia matter that anchors the cord to the coccyx
Denticulate ligaments
Lateral extensions of meninges which anchor the cord at the sides
Arachnoid and pia matter
Cauda equina p
31 pairs of spinal nerves arise from the spinal cord and exit through intervertebral foramina. The nerves that hang off the end of the spinal cord.
Gray matter
Inside spinal cord in a butterfly shape
Where is White matter in the spinal cord
Within the peripheral columns
Gray matter horns
Dorsal horns - posterior
Ventral horns - anterior
Lateral horns
Central canal
Open cancel in the center of the cord that contains CSF
Gray commissure
Around the canal in the spinal cord where fibers from
One side of the cord would cross over to the other side
Dorsal root
Passageway for sensory neurons to end the cord in the posterior horn
Dorsal root ganglion
Enlarged structure that houses the cell bodies of sensory neurons in the posterior horn
Ventral root
Contains motor neurons exiting the spinal cord
Arrangement of white matter
Arranged in columns around gray matter — composed of ascending and descending tracts. Split in half by anterior median tissue and posterior median sulcus
Epideral space
Dura
Subdural
Arachnoid
Pia matter
Mixed nerves
Because the spinal cord contains both sensory and motor neurons
Splitting of nerves exiting the spinal cord
Split into dorsal and ventral rami
Dorsal rami
Serve the skin and muscles of the back of the body
Ventral rami
Supports all areas except the thoracic area
Plexus
Dorsal rami and central rami form complex network of nerves
What extends into the intercostal nerves
Thoracic ventral rami
What contains sensory neurons and what carries motor neurons
Dorsal constrains sensory central root carries motor
Plexuses
Cervical
Brachial
Lumbosacral
Cervical plexus
C1-c5
To supply nerves if the head and neck
Phrenic nerve
Major motor branch of cervical plexus which innervates the diaphragm to trigger breathing - at the bottom
A break in the spinal cord at the cervical plexus could cause
A lack of breathing and death
Lung cancer can press on phrenic nerve
Brachial plexus
Arises from central rami of C5-T1, services the arm, and becomes five major peripheral nerves
Nerves in brachial plexus
Axillary
Radial
Median - middle of arm to wrist
Ulnar - easiest to damage. Tingling down arm
Musculotaneous
Lumbosacral
Largest. Serve the pelvic region of the trunk and limbs. Composed of lumbar plexus from L1-L4, and the sacral plexus from l4-S4.
Nerves in lumbosacral plexus
Femoral nerve
Sciatic nerve- largest nerve in body and serves the entire leg
Carpal tunnel syndrome
Damage to the median nerve in the brachial plexus
Components of a reflex arc
Receptor - action potentials originate
Sensory neuron - in through dorsal root
Interneuron - in grey matter , excitatory or non
Motor neuron - out to effector
Effector
Monosynaptic reflex arc
Do not have interneurons — the neuron synapses directly onto the motor neuron
Polysynaptic reflex arc
Contains one or more interneurons
Most reflexes are
Spinal reflexes do not require involvement of the brain
Reflexes involving the brain
Superficial cord reflexes and papillary reflexes
Reflexes are categorized as
Autonomic (visceral)
Somatic
Somatic reflexes
Stretch
Crossed extensor
Superficial cord
Babinski sign
Abnormal response to the plantar reflex where the toes flare and the large toe moves upward. Normal in babies bc nerves are not fully myelinated
Stretch reflex
Initiated by tapping a tendon, which stretched the muscle
Good example is the patellar reflex
Crossed extensor reflex
Incorporated the withdrawal reflex with an extension of an opposite limb
Superficial cord reflexes
Initiated by stimulated if receptors in the skin and mucosal
Ex. Plantar reflex where
Cranial nerve reflexes
Reflexes mediated by the cranial nerves — ex. Gag reflex
Autonomic reflexes
Pupillary reflex
Salivary reflex
Autonomic reflexes
Autonomic (visceral) - mediated through the ANS - usually do not know they’re occurring— blood pressure, sweating
Somatic reflexes
involve stimulation of skeletal muscle by the somatic division of the nervous system
Pupillary reflex
Eye reflexes involving the optic nerve
What causes pupils to constrict
Parasympathetic branch of ANS
Salivary reflex
Salivary glands produces saliva causes by increased parasympathetic activity due to smells
Major nerves in Lumbosacral plexus
Femoral thag services the thigh
Sciatic (largest in body) that serves the entire leg
What are pins and needles caused by
Compression on the sciatic nerve
When is the stretch reflex active and interactive
Undertone with peripheral damage
Hyperactive with damage in descending tracts of spinal cord
What causes pupils to dilate in a dark room
Impulses from the sympathetic nervous system
