Task 1 Brain anatomy Flashcards
What are all the directions of the brain?
Anterior/Rostral
Posterior/caudal
Dorsal
Ventral
Medial
Lateral
Inferior
Superior
Direction of anterior/rostral?
Towards the nose end
Direction of posterior/caudal?
Towards the tail end
Direction of dorsal?
Towards the back or top of the head
Direction of ventral?
Towards the chest or bottom of the head
What is the direction of medial?
Towards the middle
What is the direction of lateral?
Away form the middle
What is the direction of inferior?
Lower or below
What is the direction of superior?
Upper or above
What parts conform the nervous system?
Central nervous system and peripheral nervous system
What is the central nervous system?
Division of the nervous system which consists of the brain and spinal cord
Why is the central nervous system referred as central?
Because it combines information from the entire body and coordinates activity across the whole organism
Why is the central nervous system the most protected system of the body?
Because it is covered by three meninges and cerebrospinal fluid
What is the peripheral nervous system?
Division of the nervous system containing all the nerves that lie outside of the CNS
What is the role of the peripheral nervous system?
To connect the CNS to the organs,limbs and skin.
Why does the PNS allow the brain and spinal cord to receive and send information to other areas of the body?
Because it allows us to react to stimuli in the environment
What two divisions form the peripheral nervous system?
The somatic nervous system
The automatic nervous system
What is the somatic nervous system?
Is the part that interacts with the external environment
What two types of nerves conform the automatic nervous system?
The sympathetic nerves
The parasympathetic nerves
What are the sympathetic nerves?
Those nerves that project from the CNS in the lumbar and thoracic regions of the spinal cord
What are parasympathetic nerves?
Those nerves that project from the brain and sacral region of the spinal cord
What is the ventricular system?
Set of four interconnected ventricles in the brain, where the CSF is produced.
What is within each ventricle?
A region of choroid plexus that is involved in the production of CSF
What is the ventricular system responsible for?
The production, transport and removal of CSF
What is CSF?
Plasma that surrounds the brain and spinal cord.
What are the three functions of the CSF?
- Protection
- Buoyancy
- Chemical stability
CSF :Protection
CSF acts as a cushion in the brain which limits neural damage
CSF. Buoyancy
Brains weight is reduced which prevents excessive pressure
Chemical stability
It creates an environment that allows the proper functioning of the brain
What is the ventricular system composed of?
Lateral ventricles
Third ventricle
Fourth ventricle
Where are the lateral ventricles located?
Within their respective hemispheres of the cerebrum
How does the volume of the lateral ventricles increases?
With age
Where is the third ventricle located?
Between the right and left thalamus
What does the fourth ventricle receive and where does it go afterwards?
CSF from the third ventricle via the cerebral aqueduct which goes to the central spinal canal and the subarachnoid cisterns
What is the telencephalon?
Is the largest part of the brain
What is the telencephalon composed of?
Right and left hemispheres
How are the two hemispheres connected? And what is it?
They’re joined by the corpus callosum which is the largest cerebral commissure
What does the corpus callosum do?
It transmits messages from one side to the other
What does each hemisphere control?
The opposite sides of the body
What is the cerebral cortex?
The tissue layer that covers the cerebral hemispheres
What is the appearance of the cortex?
Folded with hills and valleys
How many neurons does the cortex contain?
16 billion neurons arranged in specific layers
What is gray matter?
The layer that is mainly composed of un myelinated (lack of myelina) and small neurons
What is white matter?
Layer beneath the cortex composed of large myelinated neurons
What does the folding of the brains surface area allows?
Increases the brains surface area allowing More neurons to fit inside the skull and enabling higher functions
What are the folds of the cortex?
They’re known as gyrus
What are the wrinkles between the folds?
They’re known as sulcus
What is the neocortex?
90% of human cerebral cortex is called neocortex
What is the neocortex divided in?
Six layered cortex of recent evolution
In what two types of cells are the the cortical neurons divided?
Pyramidal cells and Stella te cells
What are pyramidal cells?
Large multipolar neurons with pyramid shaped bodies, large dendrite (apical dendrite) that extends from the apex of the pyramid ñ, straight towards the cortex surface
What are Stella te cells?
Small star shaped interneurons meaning that they are neurons with small axon or without it
What is the columnar organization?
They are the neurons in a given vertical column of neocortex often form a small circuit that performs a single function
What is the hippocampus mainly composed of?
Three major layers
Where is the hippocampus located?
At the medial edge of the cerebral cortex folding back on itself in the medial temporal lobe
What does the shape of the hippocampus resembles to?
A sea horse
What is the major role of hippocampus?
Role in memory particularly memory for spatial location
What the large wrinkles in cortex?
Fissures
How are small wrinkles called?
Sulci (sulcus)
How are the ridges between fissures and sulci called?
Gyri(gyrus)
Four gyri?
Precentral gyri
Postcentral gyri
Superior temporal gyri
Consulate gyrus
What is the orecentral gyri?
Is the largest gyri in the frontal lobe and is situated in front of the postcentral gyrus
What is the pistcentral gyri?
Prominent gyrus if the parietal lobe
What is located in the postcentral gyri?
The primary somatosensory cortex (=main sensory receptive area for sense of touch)
What is the superior temporal gyri?
In the temporal lobe
What is the superior temporal gyri invoked in?
Perception of emotions in facial stimuli; auditory processing; function of language in individuals who are developing a sense of language
What is the cingulate gyrus?
Curved fold covering the corpus callosum
What is the cingulate gyrus part of?
It is a component of the limbic system
What is thecingulate gyrus involved in?
Processing emotions and behavior regulation
Also helps to regulate autonomic motor function
What can damage to the cingulate gyrus lead to?
Cognitive emotional and behavioral disorders
What is the longitudinal fissure?
The largest fissure
What are cerebral commisures v
Hemisphere connecting tracts
What is the corpus callosum?
The largest cerebral commisure
What are the central fissure and lateral fissure?
They divide each hemisphere in 4 lobes
In what fourlobes do the central and lateral fissures divide the hemispheres?
Frontal
Parietal
Temporal
Occupital
How do lobes function?
Their function is provided by th different areas that are located in each of them
What is the frontal lobe?
Most anterior part of the cerebral cortex
Where does the frontal lobe end?
At caudal site of central sulcus
What does the frontal lobe deal with?
Personality, behavior, emotions ñ, judgement, planning and problem solving
In the frontal lobe there’s a thing called brochas area what is it responsible for?
Speaking and writing
In the frontal lobe there is a structure known as motor strip what is it in charge for?
Body movement
Other things the frontal lobe is responsible for,
Intelligence concentration self awareness
Where is the parietal lobe?
Posterior to the frontal lobe
What does the parietal lobe interpret?
Language and words
Within the parietal lobe there is a structure known as sensory strip what is it responsible for?
Sensation from body such as touch pain temperature
What is the occipital lobe?
Most posterior part of the brain
What is the occipital lobe in charge for?
It interprets visual perception (color, light, movement)
Why is thenoccupital libe sonimportant?
Because we use mainly visual input to guide our behavior
Where is the temporal lobe located?
Ventral to the frontal and parietal lobes
What are the three general functional areas of the temporal lobe?
1Superior temporal gyrus
- Inferior temporal cortex
- Medial temporal cortex
What is the superior temporal gyrus involved in?
Hearing and language (wernickes area)
What is the inferior temporal cortex?
Involved in identifying complex visual patterns
What is the medial temporal cortex involved in?
It is important for certain kinds of memory
What happens when you damage the brocas area(left frontal lobe)?
We have difficulty moving the tongue or facial muscles to produce the sounds of speech
Though we can still read and understand spoken language
So what is brocas aphasia?
Difficulty in speaking and writing forming letters and words
What happens if you damage the wernickes area (left temporal lobe)?
Then you’re dealing with wernickes aphasia
What happens when you have wernickes aphasia?
You may speak in long sentences that have no meaning add unnecessary words and even create new ones
You are able to make speech sounds but not to understand them
What is an aphasia?
A disturbance of language affecting speech production comprehension reading or writing due to brain injury (stroke or trauma)
What is the limbic system?
Is a circuit of midline structures that circle the thalamus
What is the limbic system center of?
Our emotions ñ, learning and memory
What is the limbic system associated with?
The regulation of motivated behaviors (fleeing feeding fighting sexual i recourse etc)
Where is the limbic system located?
Well the limbic system is not an entirely separate system but a part of the telencephalon diencephalon and mesencephalon (brainstem)
What does the limbic system consist of?
HIPPOCAMPUS
AMYGDALA
FORNIX
CINGULATE CORTEX
MAMMILLARY BODY
SEPTUM
where is the hyppocampus?
It is located in the temporal lobe but still part of the limbic system
What is the hippocampus involved in?
Learning memory and spatial awareness
Where does the hippocampus play an important role?
In the consolidation of information from short term memory to long term memory
Why is the hippocampus important to Alzheimer’s disease?
It is the first region of the brain to suffer damage with a short term memory loss and disorientation among the early symptoms
Where is the amygdala located?
In the anterior temporal lobes of the brain also considered part of the basal ganglia
What are the primary times of the amygdala?
Processing of memory decision making and emotional responses (fear anxiety and aggression)
What is the amygdala associated with?
The reward system
What is the amygdala responsible for?
The emotional reactions of PTSD patients
Where is amygdala disfunctuon found?
In people with bipolar disorder
What is the fornix?
The major tract of the limbic system
What does the fornix connect?
The mammillary bodies and the hippocampus
What is the surgical transection in humans?
Cutting of the fornix along its body
What can surgical transection in humans lead to?
Memory loss
What is the cingulate cortex?
Large strip of cortex in the cingulate gyrus on the medial surface of the cerebral hemispheres just superior to the corpus callosum
Form who does the cingulate cortex receive inputs?
The thalamus and neocortex
What is the cingulate cortex involves with?
Emotion formation and processing learning and memory
In what types of illnesses is the cingulate cortex important?
On disorders such as depression and schizophrenia
What are the mammillary bodies?
They’re located on the under surface of the brain as part of the diencephalon at the ends of the anterior arches of the fornix
What does the mammillary body act like?
Relay for impulses coming from the amygdala and hippocampus
What does the mammillary body contribute with?
Alertness and memory formation
What does damage to the mammiliary body leads to?
Impaired memory (anterograde amnesia)
Where is the septum located?
In the midline of the brain, between the two cerebral hemispheres ñ- attached to the corpus callosum
What is the septum connected to and with?
Cuando n estes with mammillary bodies to the amygdala and hippocampus so completing the limbic ring
What can damage to the septum may lead to,
Damage to it can lead to developmental disorders. Symptoms include vision difficulty, low muscle tone, hormonal problems ñ, seizures and intellectual problems
What is the basal ganglia?
Group of forebrain nuclei including caudate nucleus Puta men and globus pallidus they work with the cerebellum to coordinate fine motions (fingertips movements)
Structure of basal ganglia?
Sweeping out of each amygdala is the caudate connected to the Putamen
Together(caudate and putamen) they form the striatum
The remaining structure is the pale circular one globus pallidus
What is the structure of basal ganglia associated with?
Two nuclei in the midbrain substantia nigra and subthalamic nucleus
Where does basal ganglia play a role?
I the performance of voluntary motor responses
What does lesions of basal ganglia produce and two famous diseases?
Produce movement impairments
Parkinson’s disease and Huntington’s disease
What is Parkinson’s disease?
Characterized by rigidity tremors and poverty of voluntary movement
What is Huntington’s disease?
Progressive brain disorder that causes uncontrolled movements emotional problems and loss of thinking ability (cognition)
What is the diencephalon?
Is the posterior part of the forebrain, located under the cerebrum
What is the functions of the diencephalon?
To coordinate muscle movements and maintain posture and balance
What does the diencephalon consist ofV
Thalamus and hypothalamus
What is the thalamus?
A large two lobed structure that constitutes the top of the brain stem one lobe on each side of the third ventricle
How are the two lives of the thalamus joined?
By the massa intermedia
What is the massa intermedia?
A functionless mass of gray matter in the midline of the third ventricle
What does the thalamus serves as?
A communication center as it receives information from the different lobes and then gives it on to other brain areas
How to understand thalamus nuclei?
With sensory relay nuclei which are nuclei that receive signals from sensory receptors, process them and transmit them to the appropriate areas of sensory cortex
Where is the hypothalamus located?
Below the anterior thalamus (hypo=below)
What is the hypothalamus master of?
The autonomic system
What is the hypothalamus important role?
The regulation of several controlled/motivated behaviors
Such as eating sleeping or sexual behavior
It also regulates body temperature blood pressure emotions and secretion of hormones
How does the hypothalamus apply his effects?
By regulating the release of hormones from the pituitary gland also known as the master gland though it also controls other endocrine glands in the body
What does the pituitary gland secrete?
Hormones that control sexual development promote bone and muscle growth and respond to stress
In addition to the pituitary gland what other two structures appear on the inferior surface of the hypothalamus?
The optic chiasm and the mammillary bodies
What is the optic chiasm?
Point at which the optic nerves from each eye come together
Where is the optic chiasm located?
At the bottom of the brain immediately below the hypothalamus
What are the mammillary bodies?
Pair of spherical nuclei located on the inferior surface of the hypothalamus behind the pituitary considered to be part of the hypothalamus
What is the mesencephalon?
Midbrain
What are the two divisions of the midbrain?
Tectum and tegmentum
What is the tectum?
Is the dorsal surface of the midbrain
In mammals whatbis tectum composed of?
Two pairs of bums called the colliculi
Superior and inferior
What is the superior colliculi?
Anterior pair it has a visual function
What’s the inferior colliculi?
Is the posterior pair it has an auditory function
What is tegmentum?
División of the mesencephalon ventral to the tectum
What are the theee colorful substructures of the tegmentum?
Perisqueductal gray
Substantia nigra
Red nucleus
What is the periaqueductal gray?
Gray matter situated around the cerebral aqueduct
What is the cerebral aqueduct?
Duct connecting the third and forth ventricles
Why is the periaqueductal gray important?
Because of its role in mediating the analgesic (pain-reducing) effects of opiate drugs
What is substantia nigra?
Black substance part of the basal ganglia located in the midbrain
Why is substantia nigra important?
It has an important role in reward and movement
What does substantia nigra contain?
Dopamine-producing cells (Parkinsons disease)
What is the red nucleus?
Pale pink structure in rostral midbrain involved in motor coordination. Located in the tegmentum of the midbrain next to the substantia nigra
What is the metencephalon ?
It is home to many ascending and descending tracts as well as part of the reticular formation
What is a tract?
Large bundle of nerve fibers
What is the reticular formation?
Exerts some control over which sensory signals reach the cerebrum and come to our conscious attention. It plays a central role of in states of consciousness like alertness and sleep
What are the two major divisions of the metencephalon ?
Pons and cerebellum
What is the pons?
Involved in the control of breathing communication between different parts of the brain and sensations such as hearing taste and balance
What is the cerebellum?
Large structure of the brains stem dorsal surface
What kind of structure does the cerebellum have?
An important sensorimotor one that receives information from the sensory systems spinal cord and other parts of the brain and then regulates motor movements
What is the cerebellum in charge of?
Coordination of voluntary movements such as posture balance and speech
Cerebellar damage produces a variety of cognitive deficits (decision making-use of language) because functions of the cerebellum are not restricted to sensorimotor control
What is the myelencephalon or medulla?
Is the most posterior division of the brain composed of tracts carrying signals between the rest of the brain and body
Where does the myelencephalon seem to play a role in?
In arousal
Various nuclei of the reticular formation are involved in sleeping attention movement muscle maintenance cardiac and respiratory reflexes
What is the brain stem?
Posterior part of the brain it includes the mesencephalon(midbrain) the metencephalon(pons) and the myelencephalon(medulla) of the hindbrain (sometimes also the diencephalon)
What is the hindbrain?
Is the lower part of the brainstem comprising the cerebellum pons and medulla
What does the brain stem provide?
Main motor and sensory distribution of nerves to the face and neck via the cranial nerves
Where does the brain stem play a role?
In the regulation of cardiac and respiratory function it regulates the CNS and helps us maintaining consciousness and regulating sleep cycle
