Aanatomy: What do Nerves do (Part 1) Flashcards
What are the functions of the Nerve system?
Sense things (sensory functions)
Move about (motor/organ functions)
Make secretions (included as organ function)
React reflexly (reflexes)
Higher functions
How can the nervous system be divided?
Central Nervous system
Peripheral Nervous system
In the CNS what is a group of cell bodies called?
A Nucleus
In the PNS what is a group of cell bodies called?
A ganglion
What are bundles of axons travelling in the CNS called?
A Tract
What are the bundles of axons travelling in the PNS called?
A Peripheral nerve
What covers the axon for insulation?
Myelin sheath
When is the term “nerve” used?
When referring to the peripheral nerve
What are bundles of axons that leave the peripheral nerve called?
Branches
Where must a peripheral nerve synapse?
In the ganglion in the PNS - where the cell bodies are found
What type of signal is sent?
Initially a electrical signal is sent. It then forms a chemical signal
How can the brain be divided into two?
The Cerebrum
The Cerebellum
How can the cerebrum be divided?
Left Cerebral Hemisphere
Right Cerebral Hemisphere
What are gyri?
Ridge on the cerebral neocortex (cortex ) of the brain
What are Sulci?
Fissure/Furrow on the cerebral neocortex (cortex) of the brain
What is the cerebral neocortex composed of?
Gyri
Sulci
How many lobes does the cerebral hemisphere consist of?
4 lobes
How are the 4 lobes of the cerebral hemisphere named?
According to the bone of the cranial vault they lie in
What are the names of the lobes of the cerebral hemisphere?
Parietal Lobe
Temporal Lobe
Frontal Lobe
Occipital lobe
What separates the 2 cerebral hemispheres sagittally of the brain?
The Longitudinal fissure
What are the 12 cranial nerves?
CN I - The Olfactory Nerve CNII - The Optic Nerve CNIII - The Oculomotor Nerve CNIV - The Trochlear Nerve CN V - The Trigeminal Nerve CN VI - The Abducent Nerve CN VII - The Facial Nerve CN VIII - The Vestibulocochlear CN IX - The Glossopharyngeal CN X - The Vagus Nerve CN XI - The Spinal Accessory CN XII - The Hypoglossal nerve
What are the parts of the brain stem?
Midbrain
Pons
Medulla Oblongata
Spinal Cord
What are the fossa of the skull?
The Anterior Cranial Fossa
The Middle Fossa
The Posterior Cranial Fossa
What Foraminae are found in the anterior cranial fossa?
The cribriform plate of the ethmoid bone
What Foraminae are found in the Middle cranial Fossa (On the sphenoid bone)?
Optic Canal
Superior Orbital fissure
Foramen Rotundum
Foramen Ovale
What Foraminae are found in the Middle Cranial Fossa (On the temporal bone) ?
Internal Acoustic Meatus
Jugular Foramen
What Foraminae are found in the Posterior Cranial Fossa (The Occipital bone)
Hypoglossal Canal
Foramen Magnum
What cranial nerve’s foramenae are in the Anterior Cranial Fossa?
CN I
What cranial nerve’s foramenae are in the Middle Cranial Fossa?
CN II - CN VI
What cranial nerve’s foramenae are in the Posterior Cranial Fossa?
CN VII - CN XII
What is the name given for a CNs journey between CNS and the peripheral structures it supplies
Its Course
What is white matter?
Myelinated axons - giving it a white appearance
What type of matter is the spinal cord?
White matter
What is the grey matter?
The outermost layer is full of cell bodies
Describe the spinal cord?
Spinal cord runs down centre
White matter is located superficcally
Grey matter deep to the white matter
Anterior Horn of spinal cord - thicker part of grey matter
Posterior Horn of spinal cord - thinner part of grey matter
What are the parts of the spine?
Cervical
Thoracic
Lumbar
Sacral/coccygeal
What foramen does the spinal cord pass through?
Passes through the Foramen Magnum
What is the spinal cord protected by?
The Vertebral canal
What does the spinal cord connect to bilaterally?
31 spinal nerves
What are the two enlargements of the spine?
Cervical enlargement
Lumbosacral enlargement
Where does the spinal cord end?
Ends at the L1/L2 disc level
What forms the Vertebral canal?
The Vertebral Foramen
What are the parts of the spine?
C1-7 T1-12 L1-5 5 Sacral Vertebrae 4 Coccygeal Vertebrae
What is the name of the part of the spine were the spinal cord ends?
The Conus Medullaris
What is the name given to the extra vertebral column with no spinal cord in it?
The Cauda Equina
How many pairs of cervical spinal nerves are there?
8 pairs
How many pairs of thoracic spinal nerves are there?
12 pairs
How many pairs of Lumbar spinal nerves are there?
5 pairs
How many pairs of sacral spinal nerves are there?
5 pairs
How many pairs coccygeal spinal nerves are there?
1 pair
Where are the spinal nerves located?
In the Intervertebral foramen
What is the name of the posterior branch of the spinal nerve?
The Posterior ramus
What connect the spinal nerve to the spinal cord?
Roots and rootlets
What connects the structures of the body wall to the spinal nerve?
The Rami
What aspect of the spinal nerve branches is bigger?
The Anterior aspect is bigger than the Posterior
Where is the anterior ramus located?
In the Anterolateral body wall
Where is the anterior roots and rootlets located?
In the Vertebral canal
Where is the posterior ramus located?
In the Posterior Body wall
What pars of the body wall do the spinal nerves supply?
Every Pair of Spinal Nerves supply one strip of the body wall
What is the dermatome map?
the “segmental” arrangement of the spinal nerves supply to the body wall
What is the dermatome of the spinal nerve?
The area of skin (strip) supplied by both the anterior and the posterior rami
What part of the dermatome does the posterior rami supply?
The Paramedian strio
What rami supply the limbs?
The Anterior Rami - Via the Plexi
What do the large anterior rami supply?
Remainder of the Posterior Part of the dematome
Lateral Dematome
Anterior Dematome
Limb Dermatome
What is a nerve plexus?
Plexi are networks of interwined anterior rami axons
What does the=cervical plexus consist of?
C1 - C4
What does the right cervical plexus supply?
Supplies the Neck Wall
What does the Brachial Plexus consist of?
C5-T1
What does the Lumbar Plexus consist of?
L1-L4
What does the Brachial Plexus supply?
Upper Limb
What does the Lumbar Plexus supply?
Lower Limb
What does the Sacral Plexus consist of?
L5 - S4
What does the Sacral Plexus supply?
Pelvis
Perineum
Lower Limb
What is the Musculocutaneous Nerve?
Named nerve branch of the Brachial Plexus
What is the musculocutaneous nerve made from?
Axons from C5 and C6 anterior rami
What do named nerves result from?
A Plexus
What are the named nerves that result in supply to the upper limb?
axillary nerve median nerve musculocutaneous nerve radial nerve ulnar nerve
How is the Peripheral Nervous system wired?
wiring going from head to brain
wiring going from brain to head
wiring going from body & limbs to brain
wiring going from brain to body & limbs
wiring going from organs to brain
2 sets of wiring going from brain to organs
wiring going from brain to “body wall organs
What are Cranial nerves wired between?
wiring going from head to brain
wiring going from brain to head
Connect with the brain
What are Spinal nerves wired between?
wiring going from body & limbs to brain
wiring going from brain to body & limbs
What are autonomic nerves wired between?
2 sets of wiring going from brain to organs
wiring going from brain to “body wall organs”
What is CNS composed of?
Brain
Spinal Cord
What are the only spinal cord segments that have lateral Horns?
T1
L2
Why do T1 and L2 have lateral horns?
Cell bodies of the next sympathetic neurones in the chain
Where are sympathetic axons in the spinal cord?
Descend from the brain in the spinal cord white matter
Describe the Sympathetic supply to the Soma.
Autonomic centres in brain send signal
Connections from T1-L2 via Rami Communicans
Sympathic trunks run the full length of the vertebral column
What cranial nerves contain the parasympathetic axons?
Cranial Nerve III
Cranial Nerve VII
Cranial Nerve IX
Cranial Nerve X
Mainly the vagus nerves
What nerves carry the parasympathetic system for organs of the hindgut, pelvis and perineum?
Sacral spinal nerves
Where does the Parasympathetic Outflow travel to?
Internal Organs
Glands
(travels to everything the sympathetic system does, but not skeletal muscle )
How many Parasympathetic ganglia are in the head?
4 Parasympathetic Ganglia