What are the two basic divisions of the nervous system that communicate information back and forth to each other?
- Central Nervous System (CNS)
- Peripheral Nervous System (PNS)
What does the CNS consist of?
What does the PNS consist of?
What are the two divisions of the PNS?
Is the sensory division of the PNS efferent or afferent?
Is the motor division of the PNS efferent or afferent?
What are the two types of sensory input?
- Somatic sensory
- Visceral sensory
What are general somatic sensory inputs?
- Proprioception in skin, body wall, limbs
What are special somatic sensory inputs?
What are general visceral sensory inputs?
- Chemical changes
- Irritation in the viscera
- Nausea and Hunger
What are special visceral sensory inputs?
What are the two types of motor motor outputs?
- Somatic motor
- Visceral motor
What kind of motor output is voluntary?
What kind of motor output is involuntary?
What is general somatic motor?
Motor innervation of all skeletal muscles
What is branchiomeric somatic motor?
What is general visceral motor?
- Motor innervation of smooth muscle, cardiac muscle, and glands
- Equivalent to autonomic nervous system (ANS)
What are the orientation vectors?
What direction is rostral for quadriped vertebrates?
Towards the beak
What direction is caudal for quadriped vertebrates?
Towards the tail
What direction is dorsal for quadriped vertebrates?
Towards the back
What direction is ventral for quadriped vertebrates?
Towards the belly
What is the neuraxis like for quadriped vertebrates?
- Roughly parallel to the ground
- Consistent through the entire neuraxis
What is the neuraxis like for bipedal primates?
- Perpendicular to the ground
- But dorsal and ventral in the brain becaome rostral and caudal in the spinal cord
What kind of species have intermediate neuraxes that could make orientation vector terminology confusing?
What orientation vector terms are consistent in the human brain and spinal cord?
What orientation vector term is used for left and right?
What orientation vector term is used for more in the middle of the body?
What orientation vector terms are used to mean toward and away from the head?
- Cranial: toward
- Caudal: away
What orientation vector terms for extremities are used to mean far and close to the middle of the body?
- Distal: farther
- Proximal: closer
What kind of plane cuts the brain dorsal/ventrally?
What kind of plane cuts the brain rostral/caudally?
What kind of plane cuts the brain laterally?
What are the major subdivisions of the brain?
What is another name for the telencephalon?
What does the telencephalon consist of?
- Basal ganglia
What is another name for the diencephalon?
What does the diencephalon consist of?
What is the prosencephalon?
What is another name for the prosencephalon?
What is another name for the mesencephalon?
What does the mesencephalon consist of?
- Colliculi (hills)
- Tectum (roof)
- Tegmentum (covering)
What does the metencephalon consist of?
What does the myelencephalon consist of?
What does the hindbrain consist of?
What does the brainstem consist of?
What is CSF?
- Cerebral spinal fluid
- Cell-free ultra filtrate of blood formed by the choroid plexuses
What forms the CSF?
Where are the choroid plexuses located?
In each ventricle of the brain
What are ventricles in the brain?
What are the 1st and 2nd ventricles of the brain? Where are they located?
- Lateral ventricles
- In the cerebral hemispheres
Where is the 3rd ventricle of the brain located?
In the diencephalon
What is the 3rd ventricle connected to? How?
- 4th ventricle
- Via the cerebral aquaduct
Where is the 4th ventricle located?
Between the pons & medulla oblongata
What is the 4th ventricle of the brain continuous with?
The central canal of the spinal cord
What is a gyrus?
What is a sulcus?
What is a fissure?
A deep sulcus
What is the circle of Willis?
An arterial anastomosis between the internal carotid and posterior cerebral arteries, and the anterior cerebral arteries
How are arterial aneurysms diagnosed?
From visual disturbances resulting from pressure on the optic chiasm/nerves
Where do 80% of arterial aneurysms occur?
At the circle of Willis
What kind of issue creates visual signs similar to arterial aneurysms, leading to early diagnosis?
Tumors or cysts on the hypothalamus and pituitary gland
What do you see if you pull the frontal lobe and temporal lobe apart at the lateral fissure?
What do cortical areas do?
- Sensory and motor processing
- Cognitive functions
What is the homunculus?
Somatosensory and motor maps
Who was Wilder Penfield?
- Mapped the homunculus during surgeries for focal motor epilepsy
What is in the deep cerebrum?
The basal ganglia (nuclei)
What are the two parts of the corpus striatum?
- Caudate nucleus
- Lentiform nucleus
What is included in the basal ganglia?
- Corpus striatum
- Fibers of corona radiata
- Internal capsule
What fibers come out of the corpus striatum?
Fibers of corona radiata
Which fibers run deep to lentiform nucleus?
What happens when there is abnormal functioning of the basal ganglia?
- Several movement disorders
- Parkinson's disease
- Huntington's chorea
- Tic disorders (Tourette syndrom, OCD, etc.)
What are the two parts of the lentiform nucleus?
What is included in the epithalamus?
- Pineal gland
- Stria medullaris
What does the greek "epi" mean?
On or above
What does the greek "hypo" mean?
What is the thalamus?
- Sensory and pre-motor relay nuclei
- Target of basal ganglia and descending cortical feedback
What does dura mater mean?
What are the 3 meningeal layers?
- Dura mater
- Pia mater
What does arachnoid mean?
What does pia mater mean?
Describe the dura mater meningeal layer.
- Forms flat partitions
- Falx cerebri
- Tentorium cerebelli
What is the purpose of forming flat partitions in the dura mater?
- Provides stabilization and support for the brain
- Limits excessive movement
Where is the falx cerebri located?
Positioned in the central sulcus, between hemispheres
What does the tentorium cerebelli do?
Separates the cerebrum from the cerebellum
Describe the arachnoid meningeal layer.
- The arachnoid is not always observed as a discrete membrane
- Rather as the inner lining of the dura
- Does not extend down to the sulci
- The space beneath it is filled with CSF and criss-crossed with a spiderweb-like matrix of fine fibers that led to its name
Describe the pia mater meningeal layer.
- Delicate, highly vascularized membrane
- Clings tightly to brain over every sulcus and gyrus
- Hard to separate from the brain
What is subdural space?
- Potential space
- Between the dura mater and arachnoid
What is the subarachnoid space?
- Real space
- Filled with CSF
- Between the arachnoid and pia mater
What are 3 functions of the CSF?
- Communication (still doing research)
What does choroid plexus mean?
- Choroid- colored (b/c of the dark appearance)
- Plexus- network
- Network of colored capillaries
Where are choroid plexuses located?
In the roof of each ventricle
What does CSF move through to get from the lateral ventricles to the 3rd ventricle?
What does CSF move through to get from the 3rd ventricle to the 4th?
What does aperture mean?
It's like a window or opening
How does cerebral spinal fluid exit the 4th ventricle?
Where does CSF go onces it's reabsorbed?
Returns to venous blood
How oftend oes the circulation of CSF occur?
Replaced every 6-8 hours
How many choroid plexus exist in each ventricle?
What is the central canal?
Fluid-filled space connected to the cerebral ventricals
What is grey matter in the spinal cord?
Dominated by neuronal cell bodies and neuroglia cells
What does grey matter generally look like in spinal cords?
- "H" or "butterfly" shaped
- Horns- anterior (ventral), lateral, posterior (dorsal) (sensory & motor nuclei)
- Grey commissure- axons crossing from one side to other
What is white matter in the spinal cord?
- Large number of myelinated and unmyelinated axons
- Contain tracts: sensory or motor
How is white matter arranged?
Arranged in columns of ascending and descending axons
What are tracts?
Axons in the same direction
What two parts of the spinal cord are thicker?
- Groups of neurons that innervate parts of the body that have more muscle activity?
- Ex. fingers and toes have more muslce movement than the stomach
What is the gross anatomy of the spinal cord like?
- Similar to the brain in terms of layers
- Has dorsal/ventral columns (white matter)
- Dorsal/ventral horns (grey matter)
- Spinal canal
- Spinal nerve- Dorsal root ganglia, ventral root, dorsal root
On what side does the spinal nerve send motor information?
On what side does the spinal nerve send sensory information?
In what direction do sensory tracts go?
From sacral to cervical
In what direction do motor tracts go?
From trunk to extremity