Anatomy Nervous System Final
Terms in this set (82)
What is the cauda equina?
horse's tail, collection of nerve roots that project inferiorly from the end of the spinal cord at L1
How many vertebrae are there in total?
What are the two segmental levels of enlargement in the spine?
1. Brachial/Cervical enlargement
2. Lumbosacral enlargement
Where does the brachial/cervical enlargement in the spinal cord branch off too?
Where does the lumbosacral enlargement in the spinal cord branch off too?
There are 33 vertebrae, but how many pairs of spinal nerves are there?
What is the purpose of the cervical and lumbosacral enlargements in the spinal cord?
To generate the 31 pairs of spinal nerves of the limbs
Meninges of the spinal cord:
dura mater, arachnoid mater, pia mater (same as the brain)
Where is gray matter located?
What is the dorsal horn?
The posterior region of gray matter in the spinal cord that receives sensory information
What is the central horn?
The anterior region of gray matter in the spinal cord that receives motor information
What is the intermediate zone of the spinal cord?
A gray matter region that is a group of interneurons
What is the lateral horn?
A gray matter region of the spinal cord that contains sympathetic nerve fibers and receives input from the brain stem, organs, and hypothalamus
How many pairs of spinal nerves do we have?
What are the 5 sections of the vertebrae?
How many pairs of cervical spinal nerves are there?
How many pairs of thoracic spinal nerves are there?
How many pairs of lumbar spinal nerves are there?
How many pairs of sacral spinal nerves are there?
How many pairs of coccygeal spinal nerves are there?
What are dermatomes?
a specific segment of skin supplied by a single pair of spinal nerves (sensory nerves)
Spinal nerves have cutaneous (skin) distributions called...
What are myotomes?
group of muscles supplied by a single nerve root (motor nerves)
How many major spinal nerve plexuses are there?
What is the major spinal nerve plexus that runs through the cervical region?
What are the major spinal nerve plexuses that runs through the brachial (or thoracic) region?
4 Ulnar and median nerves
What is the name of a lumbar and sacral plexus together?
What does the lumbosacral plexus do?
Provides innervation of lower extremities
What does the lumbosacral plexus contain?
the obturator, femoral, tibial and common fibular nerves
What do nerves that arrive from plexuses supply?
Skeletal muscles and skin
What happens when the spinal cord is transected?
a total loss of motor and sensation in regions inferior to the injury
Where is the transection of the spinal cord when one becomes a paraplegic?
Transection between T1-L1: this is the paralysis of the legs
Where is the transection of the spinal cord when one becomes a quadriplegic?
Transection in the cervical region, this is a paralysis of all 4 limbs
What are the 4 parts of the brain?
1. Brain stem (most inferior)
What does the brain stem do?
Connects the brain and spinal cord, and connects the spinal cord and cerebellum to the remainder of the brain
How many pairs of cranial nerves arise from the brainstem?
10 of the 12 pairs
What does the brainstem control?
BP, HR, breathing
What are the 3 parts of the brain stem?
1. medulla oblongata
What does the medulla oblongata do?
controls breathing, heart rate, breathing, coughing, sneezing, hiccuping, swallowing, voluntary muscle movement, etc.
Where is the pons located in the brainstem?
superior to the medulla oblongata
Where is the medulla oblongata located?
most inferior right above the spinal cord
where is the midbrain located?
this is she smallest part of the brainstem, and it is superior to pons
What does the pons connect?
The cerebrum and cerebellum
What does the pons do?
regulates breathing, swallowing, balance, chewing and salivation
Why do the pons and medulla oblongata overlap in functions?
Because the nuclei from the lower pons extend into the upper medulla oblongata
What does the cerebellum consist of?
gray and white matter
What 3 main functions (controls) does the cerebellum have?
1. Balance and eye movements
2. posture, fine motor coordination
3. involved with planning, practice, and learning of complex movements
Where is the diencephalon located?
between brainstem and cerebrum
What three parts does the diencephalon consist of?
What does the thalamus do?
it is the integration center, involved with emotions and pain perception
What does the hypothalamus do?
It is vitally important to overall body homeostasis and bodily regulations, control of hormones (endocrine system)
How many lobes does the cerebrum consist of and what are they?
What divides the left and right hemisphere of the cerebrum?
The longitudinal fissure
What does the frontal lobe do?
Involved with voluntary motor function, motivation, aggression, sense of smell and mood
What does the parietal lobe do?
contains the major sensory areas and receives sensory input such as touch, pain, temperature, balance and taste
What is the function of the occipital lobe?
What does the temporal lobe do?
hearing and smelling, memory, abstract thought, and judgement
What is CSF?
Where is CSF located?
In the subarachnoid space (below arachnoid mater- meninges)
What is the purpose of CSF?
1. Buoyancy- so the brain is not crushed by its own weight
2. Protection: liquid cushion to protect from sudden movements
3. Environmental stability: transports nutrients to the brain and removes waste
Which layer of meninges attaches directly to the brain?
How much of the blood pumped by the heart does the brain require?
What coats an axon?
A myelin sheath
What process occurs at the synapse?
A neurotransmitter is released when a signal is transmitted. Neurotransmitter is released from one axon and attaches to the dendrite of the next neuron to stimulate the sodium potassium
What is the structure of a neuron?
What is a myelin sheath?
Coats the axon to help with conductivity
What do oligiodendrocytes do?
they produce myelin sheath in the CENTRAL nervous system
What do Schwann cells do?
they produce myelin sheath in the PERIPHERAL nervous system
What is the synapse?
Gap between neurons
What is the state of a nerve when it is resting?
There is a negative charge on the inside, positive charge on the outside of neuron
What happens during the process of depolarization?
Neurotransmitter opens sodium potassium pump, and allows sodium into the cell- an action potential is created and goes the whole length of the neuron
What happens during the process of repolarization?
To get back to equilibrium, potassium ions rush out of the neuron to get back to the negative charge on the inside
What sulcus separates the frontal from the parietal lobe?
Do lordotic spinal curves open anteriorly or posteriorly?
lordotic spinal curves open posteriorly (towards the back)
Do kyphotic spinal curves open anteriorly or posteriorly?
kyphotic spinal curves open anteriorly (towards the front)
What is the function of the olfactory cranial nerve?
What is the function of the optic cranial nerve?
What is the function of the oculomotor cranial nerve?
Motor: eye movement
What is the function of the hypoglossal cranial nerve?
What is the function of the facial cranial nerve?
Motor: facial expression
What is meningitis?
inflammation of the meninges caused by viral or bacterial infection, dangerous because although the brain is expanding, the skull cannot
What is the danger of a subarachnoid hemorrhage?
Can lead to a stroke, seizures, or even death