Lecture 4 - Neuroanatomy II Flashcards
What are the three sturctures that make up the diencephalon? (from superior to inferior)
- The epithalamus
- the thalamus
- the hypothalamus
What does the diencephalon surround?
the 3rd ventricle
What is the epithalamus surrounded by?
the cerebral hemispheres
What is the biggest structure in the diencephalon and what % of it does it comprise?
the thalamus, 80%
What bridges the two paired oval masses of grey matter (of nuclei) that make up the thalamus?
interthalamic adhesion
What surrounds the thalamus? What is it and what does it do?
internal capsule, thick band of white matter that allows info to go from thalamus to cerebral cortex
What are the roles of the thalamus?
- major relay centre for sensory impulses (excpet smell)
- transmits info from cerebellum to primary motor cortex of cerebrum (plays role in motor function)
- rlays nerve impulses from different areas of the cerebrum
- plays role in regulation of autonomic activities and staying conscious
What are the roles of the hypothalamus?
- one of the major regulators of homeostasis
- produces hormone to act on the pituitary gland
- regulates emotional & behavioural patterns (with limbic system)
- plays a role in regulation of eating and drinking, control of body temp and sarcadian rhythms
What branches of the hypothalamus? and what bridges them?
the pituitary gland, the infundibulum (aka infundibular/pituitary stalk)
What are the 2 structures of the epithalamus?
- the habenular nuclei
- the pineal gland
what does the habenular nuclei do?
its involved in the sense of smell and emotions to odour
what does the pineal gland do?
its part of the endorcrine system and it releases melatonine which is a hormone
What three structures make up the brainstem? from superior to inferior
- the midbrain
- the pons
- the medulla oblangata
What is the medulla oblangata a continuation of?
the superior part of the spinal cord
What are the borders of the medulla oblongata?
begins at foramen magnum (of skull) and extends to inferior border of pons (the pontomedullary junction)
What does the medulla oblangata contain?
all sensory (ascending) and motor (descending) tracts that connect the spinal cord to the brain
What are the two prominents bulges on the anterior aspect of the medulla called?
pyramids
What attached the two pyramids?
decussation of pyramids
What percent of axons pass from one pyramid to the other?
90%
What does the crossing of axons between pyramids explain?
It explains why the left side of our brain controls the right side of our body and vice versa
What do the pyramids contain?
several nuclei which plau an important role on the regulation of heart rate, blood vessel diameter, basic rhythm of breathing, reflexes for vomitting, coughning and sneezing
What control center does the pons contain?
the control center for respiration
What are the borders of the midbrain?
extends from pons up to diencephalon
What is the midbrain involved in?
auditory and visual pathway
What is the posterior aspect of the midbrain that we can see called?
The tectum
What are the two stuctures within the tectum?
- superior colliculi
- inferior colliculi
What does the superior colliculi do?
reflex center for visual activities
What does the inferior colliculi do?
reflex center for auditory pathway (from ear to thalamus)
How many cranail nerves are there?
12 pairs
What sentence can be used to rememeber the order fo the cranial nerves?
Oh Once One Takes The Anatomy Final Very Good Vacations Are Heavenly
What is the I cranial nerve, what type of nerve is it, what does it do, and where does it exit?
- Olfactory
- sensory
- olfaction (smell)
- exits at cribriform plate
What is the II cranial nerve, what type of nerve is it, what does it do, and where does it exit?
- Optic
- sensory
- vison (sight)
- exits at optic canal
What is the III cranial nerve, what type of nerve is it, what does it do, and where does it exit?
- Oculomotor
- motor
- movement of the eyeballs
- exits at orbital fissure
What is the IV cranial nerve, what type of nerve is it, what does it do, and where does it exit?
- Trochlear
- motor
- movement of the eyeballs
- exits at optic canal
What is the V cranial nerve, what type of nerve is it, what does it do, and where does it exit?
- Trigeminal
- both
- sesnory innervation to the face, motor innervation to muscles of mastication (chewing)
- has three main divisions/branches
- ophthalmic branch (exits at superior ortibal fissure)
- maxillary branch (exits at foramen rotundum)
- mandibular branch (exits at foramen ovale)
What is the VI cranial nerve, what type of nerve is it, what does it do, and where does it exit?
- Adbucens
- motor
- movement of the eyballs
- exits at the superior ortibal fissure
What is the VII cranial nerve, what type of nerve is it, what does it do, and where does it exit?
- Facial
- both
- control muscles of facial expression, taste for the anterior 2/3 of the tongue
- exits at the stylomastoid foramen
What is the VIII cranial nerve, what type of nerve is it, what does it do, and where does it exit?
- Vestibulchlear
- sensory
- hearing and equilibrium
- exits at the internal acoustic/auditory meatus
What is the IX cranial nerve, what type of nerve is it, what does it do, and where does it exit?
- Glossopharyngeal
- both
- taste for posterior 1/3 tongue
- exits at jugular foramen
What is the X cranial nerve, what type of nerve is it, what does it do, and where does it exit?
- Vagus
- both
- autonomic regulation
- exits at jugular foramen
What is the XI cranial nerve, what type of nerve is it, what does it do, and where does it exit?
- Accessory
- motor
- innervation of trapezius and sternocleidomastoif muscles
- exits at foramen magnum
What is the XII cranial nerve, what type of nerve is it, what does it do, and where does it exit?
- Hypoglossal
- motor
- speech, manipulation of food, swallowing
What Sentence can you use to remmeber what kind of nerve each nerve is? (sensory, motor or both)
Some Say Money Matters But My Brother Says Big Braisn Matter More
What is the spinal cord made up of?
nerve cells/groups of nerves
Why does the spinal cord require so much protextion?
because the nervous tissue is very delicaate and doesnt deal well with injury/damage
What is the spinacl cord protected by?
- vertebral column (ts like the skull of the spinal cord if the spinal cord was the brain)
- spinal meninges
- cerebrospinal fluid (CSF)
What are the main functions of the spinal cord?
- carry messages to/from the brain and the rest of the body
- send motor commands from brain to body
- send sensory info from body to brain
- coordinate reflexes
What are the 5 sections of vertebrae of the spinal cord and how many vertebra are in each section?
- cervical (7)
- thoracic (12)
- lumbar (5)
- fused sacral (5)
- fused coccygeal (4)
Where does the spinal cord pass through in vertebrae?
the vertebral foramen
What are the three spinal meninges (from deep to superficial)
- pia matter
- arachnoid matter
- dura mater
What are the 3 spaces between the meninges? (from deep to superficial)
- subarachnoid space
- sudural space
- epidural space
What layers is the subarachnoid space between?
- between pia and arachnoid
- contains CFS
What layers is the subdural space between?
betweem arachnoid and dura
What layers is the epidural space between?
between dura and vertebral canal
What do the denticulate ligaments do?
suspend spinal cord in dural sheath
What are the two spinal cord enlargments?
- cervical enlargment
- lumbosacral enlargment
Where is the cervial emlargment and what does it do?
- C4-T1
supplies upper extremities
Where is the lumbosacral emlargment and what does it do?
- T9-T12
- supplies lower extremities
Where does the spinal cord start and end?
the medulla oblangada to superior border of L2
What is the conus medullaris?
- termination of the spinal cord
- located between first and second lumbar vertebrae (L1-L2)
What is the filum terminale?
- extension of the pia mater
- attaches the spinal cord to the coccyx
What is the cauda equina?
- lumbar, sacral and coccygeal spinal nerves
- “horses tail”
What are the 5 internal structures of the spinal cord
- posterior median sulcus
- anterior median fissure
- white matter
- grey matter
- central canal
What does the white matter of the spinal cord consist of?
- bundles of mielinated axons, sensory neurons, interneurons and upper/lower motor neurons
What are the three funiculi of the white matter?
- posterior funiculus
- lateral funiculus
- anterior funiculus
What do each funiculi contain?
- distinct bundles of axons that have common origin or destination and carry similar information
What does the grey matter of the spinal cord consist of?
- cell bodies, neuronss, neuroglia, unmielinated axons, dendrites of interneurons, motor neurons
- grey matter is subdivided into regions called horns
What are the three horns of the grey matter?
- posterior horn
- lateral horn
- anterior horn
Posterior horn
- sensory
- contains cell bodies and xons of interneurons and axons of incoming sensory neurons
Lateral horn
- involuntary
- contains cel bodies of autonomic motor nuclei (regulate activity of smooth cardiac muscle and glands)
anterior horn
- motor (volunatry)
- contaisn somatic motor nuclei
In the grey matter, clusters of neuronal cell bodies will form function groups called nuclei.. what are the two groups of nuclei?
- sensory
- motor
What do the sensory nuclei do?
receive input from receptors via sensory neurons
What do the motor nuclei do?
provide output to effector tissue via motor neurons (ex: skeletal muscle)
What is the central canal?
- it contains CSF
- extends the entire length of the spinal cord
- is located right in the middle of the spinal cord
Information tracks of spinal cord
- sensory info is ascending (up to brain)
- motor is descending (from brain)
