The brain-Nervous system part 3 Flashcards
What are the 4 main parts of the brain?
- Cerebrum
- Diencephalon
- Brain stem
- Cerebellum
What are the 3 parts of the diencephalon?
- Thalamus
- Hypothalamus
- Epithalamus
What are the 3 parts of the brain stem?
- Midbrain
- Pons
- Medulla oblongata
True or false?
The cerebrum is the largest section of the brain.
True
Label 1-8
Where is the midbarain in relation to the diencephalon?
Inferior to the diencephalon
What does the medulla oblongta turn into as it passes through the foramen magnum?
It becomes the spinal cord
What area of the brain is this?
The medulla oblongata
What area of the brain is this?
The pons
What area of the brain is this?
The midbrain
What area of the brain is this?
The diencephalon (epithalamus, thalamus, hypothalamus)
Where is the pituitary gland in relation to the hypothalamus?
Inferior to the hypothalamus
What area of the brain is this?
The cerebellum
What area of the brain is this?
The cerebrum
What protection does the brain have?
- The skull
- The meninges
What are the 3 types of meninges?
- Pia mater
- Arachnoid mater
- Dura mater
What does the pia mater adhere to?
Adheres tightly to the surface of the brain
True or false?
The arachnoid mater includes the guri and the sulci.
False; the pia mater includes the gyri and the sulci
What space in the brain contains the CSF?
The subarachnoid space
True or false?
The arachnoid mater does not adhere tightly to the pia mater at all times.
True
What does the subarachnoid space form?
It forms cisterns
What do cisterns in the subarachnoid space contain?
They are filled with CSF
What are arachnoid villi and what is their function?
-They are finger like extensions that project into the dural venous sinuses that.
-They are one way valves that allow CSF into the blood, but not blood into the CSF
How many layers are there to the dura mater in the brain?
2 layers (the spine only has one)
What are the layers of the dura mater?
- Periosteal layer (outer)
- Meningeal layer (inner)
True or false?
The epidural space in the brain is located between the arachnoid and pia mater.
FALSE; THERE IS NO EPIDURAL SPACE IN THE BRAIN
Are the layers of the dura mater fused?
Yes, except where they surround the venous sinuses
What pathology is being shown in this image?
An epidural bleed
What is the weakest part of the skull?
The pterion
What can a epidural bleed lead to?
Increases intercraineal pressure which can lead to herneation
What is the pterion a landmark for?
A landmark for the middle menningeal artery
What are the 3 extensions of the dura mater?
- Falx cerebri
- Falx cerebelli
- Tentorium cerebelli
What does the flax cerebri seperate?
Separates the 2 cerebral hemishperes
Where is the falx cerebri located in the brain and where does it attach to?
-Located in the longitudinal fissue and attaches anteriorly to the crista galli
What does the flax cerebelli separate?
Sparates the 2 hemispheres of the cerebellum
What does the tentorium cerebelli separate?
Separates the cerebrum from the cerebellum
What is occuring during a herneation in the brain?
The medulla oblonogata is being pushed into the foramen magnum
Which bleed is more severe; a subdural bleed, or an epidural bleed? Why?
Epidural bleed; because epidural bleed involves the arterioles as opposed to the venuoles in a subdural bleed.
What is located within the sinuses of the brain?
Venous blood
Picture for understanding.
Absorb all information through osmosis :)
Label 1-3
1=Flax cerebri
2=Tentorium cerebelli
3=Falx cerebelli
What are the red and blue arrows pointing to?
Red: Falx cerebri
Blue: Tentorium cerebelli
What are the 2 arrows pointing to in this image?
Upper arrows: Flax cerebri
Lower arrows: Tentroium cerebelli
What pathology is being shown in this image?
Tumours within the cerebellum and cerebrum
What are the 3 sources of blood flow within brain?
- Internal carotid artery
- Verebral artery
- Internal jugular vein
What does the internal carotid artery supply blood to?
Supplies blood to the anterior and middle parts of the brain
What does the verebral artery supply blood to?
Supplies blood to the posterior part of the brain
What is the function of the internal jugular vein within the brain?
Blood drains from the dural venous sinuses aand deeper veins into the internal jugular vein
How much of the brain represents our total body weight?
2%
How much of the bodys blood supply does the brain recieve?
20%
What percentage of the glucose and oxygen does the brain consume?
20%
True or false?
The brain can store glucose.
False
Where are tight junctions formed?
Bettween the brain tissue and capillaries
What type of neuroglia in the CNS is thought to have an important function with the blood brain barrier?
The astrocytes
True or false?
The blood brain barrier is semi-permeable.
True
What substances does the blood brain barrier allow through?
- O2
- CO2
- Steriod hormones
- Alcohol
- Caffiene
- Water
- Glucose
What substances is the blood brain barrier impermeable to?
- Proteins
- Toxins
- Most antibiotics
What can cause a breakdown of the BBB?
Trauma, inflammation and certain toxins.
What are the 3 functions of the CSF?
- Mechanical protection
- Homeostatic function
- Circulation
What substances does the CSF contain?
O2, glucose, proteins, ions
How does the CSF provide mechanical protection?
It is a shock absorber
How does the CSF provide a homeostatic function?
The pH of SCF affects the cerebral blood flow and pulmonary ventilation
What occurs during circulation in the CSF?
A minor exchange of nutrients and wastes between the blood and adjacent nervous tissue occur
Where is CSF produced?
In the choroid plexus (a network of capillaries) in the walls of all the ventricles
How many mL of CSF is produced daily?
500mL
How many mL of CSF is preent in the body at any given time?
125 mL present
Where is CSF reabsorbed?
Reabsorbed in the arachnoid villi, and then the venous blood
True or false?
Typically with CSF, reabsorption and production are equal.
True
If reabsorption of CSF is affected, what can occur?
Hydocephalus (too much fluid in the brain)
What happens to infants affected by hypdrocephalus?
The skull enlarges
Is hydrocephalus a life threatening condition?
Yes in adults because the skulll is fused and can then cause herneation
Where is CSF found in the body?
- Ventricels
- Cisterns
- Subarachnoid space or the brain and spinal cord
- Central canal of the spinal cord
How do you demonstrate a check valve (ventriculoperitoneal shunt)
RPO, 180 cm, small fs, grid, 75 kVp
What is a VP shunt?
It travels from the ventricle to the peritoneum in the abdominal cavity under the skin to provide nutrients to a removed part of the skull located in the abdomen
What do they do to treat an adult with hydrocephalus?
Remove part of the skull and put it into the abdomen. Then provide a VP shunt for nutirents to the removed part of the skull
What are the ventricles of the brain?
- Lateral ventricles (2)
- Third ventricle
- Fourth ventricle
What is the largest ventricle?
The lateral ventricles
What are the different parts of the lateral ventricles?
- Anterior/frontal horn
- Body
- Posterior/occipital horn
- Inferior/temporal horn
What does the 2 lateral ventricles contain?
CSF
What do the anterior/frontal horns communicate with?
Communicates with the thrid ventricle throught eh interventricular foramina
What does the third ventricle communicate with?
Communicates with the fourth ventricle via the cerebral aqueduct
What does the cerebral aqueduct pass through? What does it connect?
Passes through the midbrain connecting the 3rd ventricle with the 4rth ventricle
Where is the third ventricle?
Sits midline within the diencephalon
What ventricle ultimely becomes the central canal of the spinal cord?
The fourth ventricle
Where is the fourth ventricle located?
Located posterior to the pons (in the anterior part of the cerebellum)
What does the fourth ventricle communicate with?
Communicates with the subarachnoid space via 3 openings in the roof; the median aperture (1), and the lateral apertures (2)
Label 1-8
- Infeior horn
- Lateral ventricle
- Anterior horn
- Third ventricle
- Cerebral aqueduct
- Fourth ventricle
- Posterior horn
- Inferior horn
- Lateral apeture
What is the pathway of CSF starting from the fourth ventricles choroid plexus?
- Fourth ventricle
a. Through lateral and median apetures to the central canal of spinal cord OR; - Subarachnoid space
- Arachnoid villi of dural venous sinuses
- Heart and lungs
- Aterial blood
What is the pathway of CSF starting athte third ventricles choroid plexus?
- Third ventricle; through the aqueduct of the midbrain
2.Fourth ventricle
a. Through lateral and median apetures to the central canal of spinal cord OR; - Subarachnoid space
- Arachnoid villi of dural venous sinuses
- Heart and lungs
- Aterial blood
True or false?
The subarachnoid space of the brain is continous witht the subarachnoid space of the spinal cord.
True
What is the pathway of CSF starting at the lateral ventricles choroid plexus?
- Lateral ventricles; through interventricular formania
- Third ventricle; through the aqueduct of the midbrain
3.Fourth ventricle
a. Through lateral and median apetures to the central canal of spinal cord OR; - Subarachnoid space
- Arachnoid villi of dural venous sinuses
- Heart and lungs
- Aterial blood
Label 1-5
- Frontal horn of the lateral ventricle
- Thrid ventricle
- Interventricular foramina
- Falx cerebelli
- Cerebellum
Label 1-3
- Frontal/anterior horns of lateral ventricles
- VP shunt in the posterior/occipital horn of the lateral ventricle
- Falx cerebri
Label 1-6
- Temporal lobe of cerebrum
- Temporal/inferior horns of the lateral ventricle
- Cerebellum
- Pons
- 4th ventricle
- Falx cerebelli
Where is the pons located?
Directly anteiror to the 4th ventricle and posterior to the clivus
What is the cerebrum known as?
“the seat of intellegence”
What are the main functions that the cerebrum is responsible for?
Reading, writting, making calculations, speaking, remebering the past, planning for the future
What percentage of the brain mass does the cerebrum make up?
Over 80% of the brain mass
What divides the left and right hemispheres of the cerebrum?
The longitudinal fissue
True or false?
The hemisphere acts on only sensory functions of the opposite side of the body.
False; each hemisphere acts on both sensory and motor functions on the opposite side of the body.
What are the lobes of the cerebrum?
- Frontal
- Parietal
- Temporal
- Occipital
- Insula
What are the 5 gray matter present in the cerebrum?
- Cerebral cortex (Gyri, Sulci, Fissures)
- Basal nuclei
Describe the structural formation of the gyri:
Convolutions that form an out-curve
Describe the structural formation of the sulci
Shallow grooves
Describe the structural formation of the fissures:
Deep grooves
What are the 2 landmarks of the gyri?
- Precentral
- Postcentral
What are the 2 landmarks of the sulci?
- Lateral sulci
- Central sulci
What are the landmarks of the fissures in the cerebrum?
The longitudinal fissure
What does the cerebral cortex contain?
- Gryri, fissures, and sulci
- Billions of neurons
What is the basal nuclei?
Gray matter located deep within the cerebrum
What are the 2 types of basal nuclei?
- Caudate nucleus
- Lentiform nucleus
Where is the lentiform nucleus?
Posterior and lateral to the caudate nucleus
Where is the caudate nucleus located?
Follows the curve of the anterior horn of the lateral ventricle
What are the 4 functions of the lentiform nucleus?
- Subconscious control of skeletal muscle tone
- Coordination of learned movement
- Important in starting, stopping and monitoring movement
- Plays role in inititaling and terminating cognitive processes
What connects the right and left hemisphers of the cerebrum?
A bundle of white matter tracts called the corpus callosum connects the right and left hemispheres of the cerebrum
What is located deep to the cerebral cortex?
The white matter
What is the white matter in the brain and what is its function?
Tracts of neurons that connect parts of the brain to each other and the spinal cord
What function does the precentral gyrus control?
Motor function
What function does the post central gyrus control?
Sensory function
What is located between the precentral gyrus and the post central gyrus?
The central sulcus
What does the central sulcus separate?
Separates the frontal from the parietal sulcus
Label 1-5
- Insula
- Lentiform nucleus
- Caudate nucleus
- Corpus collasum
- Third ventricle
Label 5 (abc), 10, 14, 12
5: Corpus collosum
10: Pons
14: 4th ventricle
12: Cerebellum
Label 1-3
- Corpus collosum
- Caudate nuclus
- Lentiform nucleus
Label 1, 2, 3, 5, 8, 9 a+b
- Anterior horn of the lateral ventricle
- Third ventricle
- Caudate nucleus
5=Lentiform nucleus
8=Thalamus
9=a. Corpus collosum (white matter)
b=Cerebral cortex (gray matter)
What is the main function of the occipital lobe?
Primary visual area
What is the main function of the insula?
The additional area of gustation (taste)
What are the 2 functions of the temporal lobe? What structure does it contain?
- Primary olfactory area
- Primary auditory area
-Contains wernicke’s area (L side only)
Where is the diencephalon located? What is it enclosed by?
Sits on top of hte brain stem (enclosed by the hemispheres)
What are the 3 major structures of the diencephalon?
- Epithalamus
- Thalamus
- Hypothalamus
What does the diencephalon surround?
Surrounds the 3rd ventricle
What gland is located within the epithalamus?
The pineal gland
What gland is located within the hypothalamus?
The pituitary gland
What structure does the parietal lobe contain?
Wernickes area
What is wernikes area?
-General interpretive area (interprets the meaning of speech)
What is the primary area (lobe) for taste?
The parietal lobe
What structure is located within the frontal lobe?
Brocas speech area
Where is the primary motor area located at, and what is its function?
Located at the precentral gyrus in the frontal lobe which consiously moves skeletal muscle
Where is the premotor cortex located, and what is its function?
Located in the frontal lobe, and is responsible for our learned motor skills
Where is the primary somatic sensory area located?
The parietal lobes
What are the main functions of the parietal lobe?
-Recognizes pain, tempurature, or light touch
-Integrates and interprets senses
What lobe is the post central gyrus located in?
In the parietal lobe
Where is the thalamus located?
Superior to the midbrain
What does the thalamus contain and what are it main functions?
-Contains nuclei
-Nuclei serve as relay stations for all sensoryy impulses (exept smell) to reach the primary sensory area
-Transmits information from the cerebellum to the primary motor area
What is projected from the hypothalamus?
The hypophysis (pituitary gland)
List 4 functions of the pituitary gland:
- Controls the ANS
- Coordinates between nervous and endocrine system
- Controls body temp
- Regulates hunger/thirst
Where is the epithalamus located?
Superior and posterior to the thalamus and superior to the 3rd ventricle
Where is the habenular nuclei located and what is its function?
Located in the epithalamus and is responsible for emotional responses to odours
Where is the pineal gland located and what is its function?
Located in the epithalamus and is responsible for secreting melatonin and promoting sleepiness
What are the functions of the limbic system?
- Links the consuous, intellectual functions of the cerebral cortex with the unconscious and autonomic functions of the brain stem
- Memory storage
- Motivator
- Pleasure, pain, anger, fear, affection
Where is the limbic system located?
Encircles the upper part of the brain stem, inner border of cerebrum and the floor the diencephalon
What is the most superior part of the brain stem?
The midbrain
Where is the midbrain located?
Between the pons and the diencephalon
What are the 2 functions of hte midbrain?
- Coordinates head and neck movement in response to visual and auditory stimulus
- Controls the reflex center for eye movement
What crainial nerves are located in the midbrain?
- Ocularmotor (III)
- Trochlear (IV)
What crainial nerves are located within the pons?
- Trigeminal (V)
- Abdeucens (VI)
- Facial (VII)
- Vistibulocochlear (VIII)
What is the main funcction of the pons?
Together with the medulla, areas in the pons help control breathing
What crainial nerves are located within the medulla oblongata?
- Vestibulocochlear (VIII)
- Glossopharyngeal (IX)
- Vagus (X)
- Accessory (XI)
- Hypoglossal (XII)
What are the functions of the grey matter of the medulla oblongata?
- Cardiac center adjusts rate + force of heart beat
- Vasomotor center adjusts blood vessel diameter
- Respiratory centers control rate and depth of breathing
- Reflex centers for coughing, sneexing, gagging, ect
What are the 2 sections of the medulla oblongata?
- White matter
- Grey matter
What are the external bulges of the white matter called and what is their function?
-Called the pyrimids
-Responsible for decusssation of the pyrimids (crossing over)
What does the white matter of the medulla oblongata contain?
- Ascending and descending tracts to the spinal cord
- Pyramids
What are the pyramids in the medulla oblongata formed by?
Formed by the largest motor and sensory tracts in the body
Label 1, 5, 18, 19, 20, 23, 24
1=Anterior horn of the lateral ventricle
5=4rth ventricle
18=3rd ventricle
19=Epithalamus
20=Midbrain
23=Pons
24=Medulla oblongata
T/F?
The cerebrum occupies the posterior crainieal fossa?
False, the cerebellum
What are the 2 sections of the cerebellum?
- Grey matter
- White matter
How do you differenciate between the cerebellum and cerebrum on a radiographic image?
By the folia, because it has slender parallel folds
Where is the cerebellar nuclei located within the cerebellum?
Deep within the white matter
Where is the abor vitae located and what are its functions?
-Located in the white matter of the cerebellum
-Functions: Regulates posture and balance, smooths and coordinates contractions of skeletal muscle, and may have a role in cognition and language processing
What is ataxia and what can it be caused by?
-It is the loss of the ability to coordinate movements
-Can be caused by; MS, parkinsons, alcohol, tumours
Label 1-3
- Pons
- 4th ventricle
- Cerebellum
Label 1 and 2
1=Inferior/temporal horns of the lateral ventricles
2=Cerebellum
What modality is best for looking at the brain?
MRI
How many pars of cranial nerves are there and what system are the crainial nerves part of?
-12 pairs
-Part of the PNS
What do the numbers of the crainial nerves indicate?
The number indicates the order from which the crainial nerves arise from the brain, going from anterior to posterior
What are the crainial nerves in order?
- Olfactory nerve
- Optic nerve
- Oculomotor nerve
- Trochlear nerve
- Trigeminal nerve
- Abducens nerve
- Facial nerve
- Vestibulocochlear nerve
- Glossopharyngeal nerve
- Vagus nerve
- Acessory nerve
- Hypoglossal nerve
What crainial nerves are snesory?
- Olfactory nerve
- Optic nerve
What crainial nerves are motor?
- Oculomotor nerve
- Trochlear nerve
- Abducens
- Acessory nerve
- Hypoglossal nerve
What crainial nerves are mixed?
- Trigeminal
- Facial
- Glossopharyngeal
- Vagus
What does the olfactory nerve travel through?
Goes through the cribiform plate to the olfactory bulb to the tract.
What is the pathway of the optic nerve?
- Retina
- Optic foramen
- Optic nerve
- Optic chiasm
- Optic tract
- Thalamus
- Visual cortex
What structure doe the optic nerve travel through beofre going to the optic chiasm?
The larger wing of sphenoid
What is the pathway of the oculomotor nerve?
- Midbrain
- Orbit (superior orbital fissure)
- Eye
How many muscles of the eye does the oculomotor nerve innervate?
4 muscles
What is the function of the oculomotor nerve?
Rotations of the eye and eyelid
What is the pathway of the trochlear nerve?
- Midbrain
- Superior orbital fissure
- Orbit
- Eye
What are the divisions of the sensory section of the trigeminal nerve? What is its function?
- Ophthalmic V1
- Maxiallary V2
- Mandibular divisions V3
- Provides sensations from the face, nasal caities, lacrimal gland, and palate to the pons
What are the divisions of the motor section of the trigeminal nerve? What is its function?
The mandivular divisions (traveling through foramen ovale)
-Responsible for all muscles of mastication
What is the pathway of th abducens nerve? What is its function
- Pons
- Orbit (superior orbital fissure)
- Eye
-Function is to rotate the eye lateraly
What is the function of the vestibulocohlear nerve?
Equilibrium and balance
What are the functions of the glossopharyngeal nerve?
- Innervates tounge and pharynx and involved in swallowing and gag reflex
- Tate from posterior 1/3 of tounge
What does the vagus nerve innervate?
-Innervates visceral organs of thorax and abdomen
-The motor nerves go to the vocal cords and pharynx
What is the longest cranial nerve?
The vagus nerve
What branch does the acessory nerve contain?
The medullary and spinal branch
What does the hypoglassal nerve innervate?
The intrinsic and extrinic muscles of the tounge
What nerve is being represented here?
Optic nerve
Label 1-8
- Optic nerve
- Optic chiasm
- Oculomotor nerve
- Trochlear nerve
- Trigeminal nerve
- Facial nerve
- Vestibulocochlear nerve
- Abducens
Label 1 and 2
1=Petrous ridges
2=Internal auditory canal
What nervous system does the vagus nerve interface?
The parasympathetic nervous system
What happens if the vagus nerve is stimulated too much?
Vasovagal reaction
Label the blue boxes
Label 1-9
- Sulcus
- Gyrus
- Thalamus (3rd ventricle)
- Midbrain
- Pons
- Cerebellum
- 4rth ventricle
- Medulla oblongata
- Spinal cord