Neuroanatomy 1 Flashcards
The ________ System & ________ System are in charge of maintaining the Homeostasis
Nervous and Endocrine
The Nervous System is responsible for: (3)
- Behaviors
- Memories
- Movements
three basic functions of the nervous system
- sensing changes with sensory receptors
- interpreting and remembering those changes
- reaction to those changes with effectors
- muscular contractions
- glandular secretion
The nervous system is divided into two subdivisions:
the central nervous system (CNS) and the peripheral nervous system (PNS).
consists of the brain and spinal cord, located in a bony cavity. The brain is in the cranial cavity, and the spinal cord is in the vertebral canal of the vertebral column
CNS
consists of spinal nerves, cranial nerves, associated ganglia and nerve plexuses.
PNS
The peripheral nervous system is further subdivided into an
afferent (sensory) division and an efferent (motor) division.
the …… division transmits impulses from peripheral organs to the CNS. It includes the general (somatic) sensory, special sensory and visceral sensory impulses
The afferent or sensory
the …… division transmits impulses from the CNS to the peripheral organs to cause an effect or action.
The efferent or motor
the efferent or motor division is again subdivided into the
somatic nervous systemand the autonomic nervous system (ANS)
the …… nervous system supplies motor impulses to the skeletal muscles
The somatic nervous system
the …… supplies motor impulses to cardiac muscle, smooth muscle, andglands
The autonomic nervous system (also called the visceral motor)
the autonomic nervous system is further subdivided into
sympathetic and parasympathetic divisions
the …….. is one of the main subdivisions of the autonomic nervous system and governs the function of the gastrointestinal tract.
The enteric nervous system
touch, temperature, tickle, itch, pain proprioception pressure, and vibration are part of the
somatic senses - part of sensory PNS
smell, sight, taste, hearing, and balance are considered
special senses - part of sensory PNS
Pain, the stretch of organ wall, blood pressure, pH of fluids within lumen, the osmolarity of fluids are considered
visceral senses - part of sensory PNS
voluntary control of skeletal muscle are considered
Somatic motor - part of Motor PNS
the brain consists of (4)
consists of the cerebrum, diencephalon, cerebellum, and brainstem
The brainstem, in turn, includes (3)
the midbrain, pons and medulla oblongata
The ____ processes the incoming sensory and outgoing motor messages and is involved in higher mental activities such as learning, memory, and reasoning
CNS
the components of the CNS – _____ and ________ – are enclosed and protected by bony cavities, the cranial cavity and the vertebral canal, respectively.
brain and spinal cord
The nervous tissue in the CNS is organized as ____ and _____ matter
grey and white matter
The gray matter comprises nerve cell bodies, bundles of __________ (unmyelinated/myelinated) nerve fibres, non-neuronal supportive cells, the glial cells orneuroglia
unmyelinated
The white mattermainly consists of bundles of ________(unmyelinated/myelinated) nerve fibres known as______ orfasciculi(singular, fasciculus).
myelinated
known as tracts
In the spinal cord, the gray matter forms an H-shaped inner core surrounded by white matter. In the brain, however, a thin outer shell of gray matter, the______, covers the core of the white matter.
cortex
A cluster of nerve cell bodies embedded within the CNS is called a_______,whereas aggregation of nerve cell bodies outside the CNS is called a________
nucleus, ganglion
The peripheral nervous system (PNS) includes the spinal nerves, cranial nerves, associated ________, and nerve plexuses.
ganglia
embryology: brain is subdivided into 3
- forebrain (prosencephalon)
- midbrain (mesencephalon)
- hindbrain (rhombencephalon)
embryology: the forebrain (prosencephalon) is divided into
telencephalon and diencephalon (thalamus, hypothalamus and epithalamus)
embryology: The midbrain (mesencephalon) is divided into
nothing! stays the midbrain
embryology: The hindbrain (rhombencephalon) is divided into
metencephalon (pons and cerebellum)
myelencephalon (medulla)
when does the development of the brain take place?
three, four week embryo and by week 5 it has developed into its parts
rostral and caudal =
top and front
dorsal and ventral =
front and back
coronal plane
A vertical plane running from side to side; divides the body or any of its parts into anterior and posterior portions.
sagittal plane
a vertical plane which passes through the body longitudinally
The axon makes up _____ matter - where signals travel
white
The cell body and dendrites make up ____ matter - where signals stop and synapse
grey
Two cell types of nervous tissue: Support cells of the nervous system, Nourish and clean up after neurons
neuroglia
Two cell types of nervous tissue: Functional unit of the nervous system, How signals travel to and from PNS to CNS and within CNS
neurons
where can we find grey matter?
- cerebral cortex
- cortical nuclei/diencephalon (thalamus)
- grey horns of the spinal cord
where can we find white matter?
- cerebral tracts
- white columns of the spinal cord
- spinal pathways
- peripheral nerves
what describes: cell bodies (soma), dendrites, axon terminals of neurons? Where synapsing occurs between cells. Where information is processed/passing of signals
grey matter
bundles of axons forming ______ pathways in the CNS. Where signals travel from one location to another within the CNS.
white matter
Nucleus
THINK GREY MATTER in CNS
Ganglion
GREY MATTER IN PNS
Tract and/or Fasciculus
white matter in CNS
Nerve
white matter in PNS
cerebrum comprises of the ____ and ____ cerebral hemispheres within the anterior and middle cranial fossae.
right and left
In a superior view, the________separates the two hemispheres.
longitudinal fissure
Each cerebral hemisphere is a highly convoluted structure that can be divided into four main lobes;________________________, and a small hidden portion deep to the lateral sulcus, the ______(insular lobe,insular cortex).
frontal, parietal, occipital,temporal
insula
Each lobe is responsible for different aspects of brain functions; however, the primary role of these lobes is to initiate motor impulses (……. lobe),
frontal lobe
which lobe receives general sensory stimuli (…….. lobe),
to receive general sensory stimuli (parietal lobe),
which lobe receives auditory impulses (…………. lobe)
temporal
which lobe receives visual impulses
occipital lobe
which lobe receives taste impulses
insula
The outer surface of the cerebral hemispheres represents folds,…… , separated by furrows,……
gyri
sulci
There are three main sulci in each cerebral hemisphere:
- The central sulcusseparates the frontal lobe from the parietal lobe.
- The lateral sulcusis the superior boundary of the temporal lobe and separates it from the frontal and parietal lobes.
- Parieto-occipital sulcusseparates the parietal lobe from the occipital lobe
what is the outermost layer of the brain? Which is associated with a higher level of processing and functioning. How many divisions are there?
the cerebral cortex
2 - divided into right and left hemisphere
the cerebral cortex is folded to increase _________ for information processing
surface area
the bumps/folds of the cortex
Gyri
the grooves and indentations of the cortex
sulci
the deep sulcus of the cortex. What is the specific name and what does it divide?
fissure = deep sulcus
- longitudinal fissures divide hemispheres
which lobe:
cognition, control of voluntary movement, motor production of speech (expressive language)
Special Sensation: Smell
frontal
which lobe:
processes sensory information
General sensations: pain, pressure, temperature, touch, tickle, and vibration
Special Sensations: taste
parietal
which lobe: processes memories
Special Sensation: auditory information
temporal
which lobe: primarily responsible for processing visual sensation
(special sensation)
occipital
The central sulcus is a prominent landmark of the brain, separating the /_____ lobe from the_____ lobe
parietal from the frontal lobe
The more _______ matter cortex we have - the higher functioning we are
grey
Cerebrum: The gray matter forms thecerebral cortex and clusters of nuclei within the white matter are collectively known as___________ (nuclei)
basal ganglia
The main components of the basal ganglia include the ________ and ________ (putamen and globus pallidus) nuclei. These nuclei are involved in the coordination of motor function.
caudate and lenticular
The white matter is located deep in the cortex and is formed by ________ (myelinated/unmyelinated) nerve bundles
myelinated
nerve bundles in the CNS: help to connect signals in the SAME hemisphere
Association tracts
Gyrus to gyrus or cranial to caudal (front to back, side to side)
Long ones and short ones
connect left to right hemisphere
fibres that connect different gyri of one hemisphere to the corresponding gyri of the other hemisphere
Commissural tract
Connect similar regions from right to left, right side hearing to left side hearing, left taste to right taste
fibres include the ascending (sensory) and descending (motor) fibres connecting the cortex to the lower centers of the CNS
- allow signals to ascend or descend
projectional
- Ascending to areas in the brain
In the spinal cord, they will be given a specific name based on the modality they carry (401, DVP)
Play a KEY role in ensuring coordinated, meaningful movement
Also helps to sift out signals that are useless - the bouncer to the VIP area, signals has to meet these first
basil ganglia
There are three major areas in each cerebral hemisphere:
Primary sensory areas
Primary motor area
Association areas (Sensory and Motor)
Pathways generally tend to make synapses on one of the thalamic nuclei. The thalamus only gets a crude perception of the signal received. It can’t determine the exact location or shape; therefore, the thalamus must forward the incoming signals toward the appropriate cortical area of the cerebrum.
Final analysis and interpretation happen at the cerebral cortex, where visual pathway signals are perceived as images, auditory signals are perceived as sounds or words, or any tactile sensation would be interpreted fully (exact location, shape, weight, texture, etc.)
Only a specific type of stimulus can stimulate the receptor to produce its receptor potential.
from the receptor travels a course of peripheral nerve (either cranial or spinal) follows the tract to the thalamus and is given to the appropriate cortical area for the perception of the sense
Primary somatosensory area cortex is located in the
postcentral gyrus
The primary visual area cortex is located
occipital
The primary auditory area cortex is located in the
upper portion of the temporal lobe.
The primary gustatory (taste) area cortex is located in
insula (insular lobe)
The primary olfactory (smell) area cortex is located in the
medial aspect of the temporal lobe
_____________– Homunculus - This human-like creature illustrates different parts of the human body having different spatial presentations on the cortex.
“Cortical mapping”
primary motor cortex: The largest area that generates motor signals for the muscles of ______, muscles of ______ and muscles that functionally belong to the ____apparatus (the areas that initiate fine movements).
muscles of the hands, muscles of the facial expression and muscles that functionally belong to the vocal apparatus
primary motor cortex: ). Injury to this area leads to motor paralysis of the __________(contralateral/lateral) side of the body.
contralateral
This portion controls (creates impulses) that travel along the corticospinal tract (pathway) and feed spinal nerves, or the corticobulbar tract (pathway), providing stimuli to the nuclei of cranial nerves. These pathways start from the pyramidal cells in the precentral gyrus located in the frontal lobe (the corticospinal tract is also called the pyramidal tract because of its origin form the pyramidal cells).
The precentral gyrus extends itself over the medial and lateral cerebral surfaces. That part of the gyrus, which extends to the medial surface, produces motor signals for muscles of the __________
leg and foot
why are there two motor areas
(area that is supplied by branches of the anterior cerebral artery, so that an isolated cerebrovascular accident of this area only causes motor weakness of the leg and foot muscles).
- one produces motor signals for the leg and foot and the other produced motor signals for the rest of the body
The rest of the precentral gyrus is located on the lateral surface of the cerebral hemisphere and produces motor signals for the ____________
rest of the body
where is the primary motor area cortex located?
precentral gyrus
- Involved in conscious control of precise,
skilled, voluntary movements
where does the primary motor area cortex receive input from?
premotor area & supplementary motor areas
sensory cortex, thalamus, basal ganglia, and cerebellum
True or false: Motor control to different parts of the body comes from the appropriate part of this area as outlined by the motor homunculus
true
true or false? Size of the body parts on the homunculus is proportional to the degree of fine motor control allotted to those parts
true
Located in the frontal lobe in front of precentral gyrus, serves as a space where the patterns of movement are stored.
pre motor area
front of precentral gyrus, serves as a space where the patterns of movement are stored. Learned and several times performed movement is stored as an algorithm into this gyrus. Later, when a person wants to repeat that same type of movement that was previously learned and through the exercise mastered, the algorithm is simply imported into the _______________ gyrus that just initiates motor signals based on the information received.
precentral (primary motor)
the _____ is in front of the premotor area of the front lobe. It controls the voluntary, synchronized movement of eyeballs.
Frontal Eye Field
Frontal Eye Field: Left-sided center forces both eyes to move to the ______, and the right-sided center moves them to the ______
left-sided centre forces both eyes to move RIGHT
right-sided centre forces both eyes to move LEFT
what happens if one of two centres of the Frontal Eye Field is injured?
If one of the two centers is injured, the other side center dominates and forces eyes to “look into the side of injury.”
It is located in the inferior frontal gyrus of the frontal lobe, just anterior to the inferior part of the precentral gyrus.
broca’s area
in 99% of the population, Broca’s area is found on the _____ side of the brain
left
That area is a center for generating motor signals for the vocal apparatus. Controls how we form words
Broca’s
Its injury results in Broca or motor aphasia, where the patient…
understands the speech but cannot speak
they understand but what they are saying makes no sense (slurring)
is located around the posterior end of the lateral sulcus (loops around the end of the sulcus) in the left temporoparietal junction. (Temporal, parietal and a little occipital)
Wernicke’s area
It is critical for the understanding of language
Wernicke’s area
A person with this aphasia has empty, fluent speech and a loss of speech comprehension. Speech may be effortless and without hesitancy, but little meaningful information is conveyed. The person speaks jumbled, meaningless words
Wernicke’s aphasia
Broca’s and Wernicke’s areas are connected by a white matter tract called the _______ fasciculus
arcuate
lesion of the arcuate fasciculus results in ________ aphasia. In this condition, the patient can comprehend and articulate BUT Difficulty repeating heard speech
conduction aphasia
area is located behind the primary somatosensory area in the parietal lobe. It integrates and interprets general sensations, such as shape, texture, and weight. It compares objects by their shapes and interprets the position of body parts relative to the rest of the body. It stores that information in long-term memory
The somatosensory association area
A lesion in the somatosensory association area results in a condition known as _______________ or the inability to recognize an object placed in the hand.
astereognosis (astereognosia)
the _____________ area surrounds the primary visual area in the occipital lobe. It gives meaning and interpretation to what we see.
visual association area
- Face as familiar, this a door or a chair
the ______________ area is located adjacent to the primary auditory area on the lateral surface of the superior temporal gyrus, which enables us to interpret the sounds we hear and give them meaning.
The auditory association area
- Alarm - means get out of the way
- The sound of a piano, my husband’s voice
is located among the sensory, visual, and auditory association areas and integrates signals it receives from primary areas.
The common integrative area
which area redirects those signals into other parts of the brain, where it generally creates thoughts and ideas that we understand and then voluntarily look for the most appropriate responses.
the common integrative area
which hemisphere receives somatic sensory signals from and controls muscles on the right side of the body. This hemisphere also holds spoken and written language
left hemisphere
which hemisphere receives somatic sensory signals from and controls muscles on the left side of the body
the right hemisphere
The ____________ is located between the cerebral hemispheres and the midbrain
diencephalon
What does the diencephalon include
It includes the thalami and all other structures surrounding the third ventricle, such as the hypothalamus and epithalamus.
how is each structure orientated?
- epithalamus
- thalamus
- subthalamus
epithalamus most superiorly, the thalamus centrally, and the subthalamus and hypothalamus inferiorly.
which part of the diencephalon is an egg-shaped structure consisting of a group of nuclei, most of which are sensory.
thalamus
the thalamus plays a crucial role in…
many brain functions, serving as a processing and distribution centre, relaying and regulating information from the outside world and the internal milieu to the cerebral cortex and sustaining cortico-thalamo-cortical communication
the thalamus involves multiple activities including
including consciousness, sleep, attention, memory and sensory and motor functions.
The thalamus relays all senses (except _____) to certain sensory areas of the cerebral hemisphere.
smell
The_____________is inferior and medial to the thalamus and functions as the center of the autonomic nervous system.
hypothalamus
hypothalamus controls
thus controlling emotion, body temperature, eating, drinking, etc.
the hypothalamus also regulates the function of the major components of the endocrine system through the ______ gland.
pituitary
is a small region posterior and superior to the thalamus, mainly consisting of the______. This gland regulates the circadian rhythm (sleep/awake cycle) and distribution of pigment melanin in the skin.
The epithalamus
mainly consisting of the pineal gland
the ___________ is contained within the posterior cranial fossa, underneath the tentorium cerebelli, behind the medulla and pons from which is separated by the fourth ventricle.
cerebellum
the cerebellum consists of two cerebellar hemispheres connected by a worm-like structure, the_____.
vermis
Itis joined to the brainstem by three bilaterally paired major fibre tracts, the cerebellar peduncles. The________________carry axons that connect the cerebellum to the red nucleus of the midbrain and thalamus
superior cerebellar peduncles
The_______ cerebellar pedunclesconnect the pontine nuclei of the pons to the cerebellum.
middle
The________ cerebellar pedunclescarry bundles of axons travelling between the medulla and cerebellum, such as spinocerebellar tracts.
inferior
The gray matter forms thecerebellar cortexthatsurrounds the white matter in which deep cerebellar nuclei are located. These nuclei include the fastigial, globose & emboliform (interposed), and dentate. The globose and emboliform together are referred to as interposed nucleus.
The cerebellar cortex is thrown into folds that appear as leaf-like ridges,_____, on the surface of the cerebellum.
folia
The primary function of the cerebellum includes the coordination of…
of voluntary movements and maintaining posture and balance
The brainstem is composed of the medulla oblongata, pons and midbrain from inferior to superior. The major functions of the brainstem include but not limited to: (3)
- It acts as a passageway for all ascending and descending tracts between the cerebrum and spinal cord.
- It contains the nuclei of the cranial nerves III to XII.
- It regulates the automatic behaviours required for survival, such as respiration.
connects to the pons inferiorly and the diencephalon superiorly
the midbrain
The anterior aspect of the midbrain presents two columns, thecerebral peduncles, between which the C.N. _____ emerges.
III
These columns contain descending tracts such as corticospinal and corticobulbar tracts, collectively known as the
crus cerebri
The _____ is related to the cerebellum (posteriorly), medulla oblongata (inferiorly), and midbrain (superiorly).
pons
The anterior surface is convex and carries a longitudinal sulcus, the________, occupied by the basilar artery.
basilar sulcus
The cranial nerves ___, ___, and ____ emerge from the ponto-medullary sulcus, whereas cranial nerve __ appears at the anterolateral surface of the pons.
VI, VII, and VIII
V appears at the anterolateral surface
The white matter of the pons is formed by the ascending and descending tracts. The gray matter is organized as nuclei embedded in the white matter. Some of these nuclei are related to the cranial nerves __, ___, __, and ___
V, VI, VII, and VIII.
The other major nuclei include but are not limited to the_______ nucleithat act as a relay center for motor pathways between the cerebrum and cerebellum to coordinate voluntary movements
pontine
Two important nuclei are found within the pons that add more control to the respiration –
pneumotaxic and apneustic area.
The ______________ or_________is pyramidal in shape, separated from the pons by a transverse sulcus, theponto-medullary sulcus, superiorly and continuous with the spinal cord inferiorly.
medulla oblongata or medulla
Viewing anteriorly, there is an elevation, the_______,on either side of the median anterior fissure formed by the pyramidal tracts.
pyramid
Lateral to the pyramid is a second elevation, the______, that overlies the inferior olivary nucleus.
olive
The cranial nerves ___, ____, ____, and ____ emerge from the anterolateral surface of the medulla oblongata
IX, X, XI, and XII
At the junction of medulla and spinal cord one can find the _______________ that deep to that the corticospinal tracts cross each other
decussation of pyramids
As part of the CNS, the ____________ a is composed of gray and white matter, the arrangement of which is the same as the spinal cord in the inferior half of the medulla. However, in the superior half of the medulla, the gray matter is embedded within the white matter as clusters of nuclei.
medulla oblongata
is not an individual section of the brain but an integral part of the brain stem. It is a collection of nuclei running vertically throughout the brainstem in three columns (the median, medial, and lateral columns).
reticular formation
Its functions include but are limited to, control of skeletal muscle, pain modulation, control of autonomic and endocrine systems, circadian rhythms, and consciousness.
reticular formation
To prevent sensory overload, one of its tasks is to filter out up to 99% of all incoming sensory signals, preventing them from being consciously perceived.
reticular formation
The __________ receives an enormous number of sensory signals from different parts of the body, inclusive of special senses such as vision or hearing.
reticular formation
It responds to some stimuli, potentially disrupting a relatively constant flow and unchanged level of intensity of incoming signals
reticular activating system (RAS) (or ascending reticular activating system (ARAS).
(A person will fall asleep with the air conditioner running, and the constant humming sound of the air conditioner will be eliminated by the reticular formation; upon hearing the ring sound of an alarm clock, that person will wake up. A similar scenario can be used to explain the response of RAS to visual or cutaneous stimuli).
Additionally, the reticular formation is involved in regulating our circadian rhythm (internal clock) and sleep-wake cycle, plus it makes its input to the spinal cord (reticulospinal pathway). This pathway contributes to _________.
- A general anesthetics work to suppress this system
muscle tone
