Neuroanatomy 1 Flashcards
The nervous system & endocrine system are in charge of…
maintaining the homeostasis
the nervous system is responsible for:
- behaviours
- memories
- movements
3 basic functions of the nervous system
- sensing changes with sensory receptors
- interpreting and remembering those changes
- reacting to those changes with effector
what are the 2 subdivisions of the nervous system?
central nervous system (CNS) and peripheral nervous system (PNS)
the CNS consists of the…
brain and spinal cord
the PNS consists of…
spinal nerves, cranial nerves, associated ganglia and nerve plexuses
the peripheral nervous system is further subdivided into…
afferent (sensory) division and an efferent (motor) division
the afferent or sensory division transmits impulses from…
peripheral organs to the CNS
the efferent or motor division transmits impulses from…
the CNS to the peripheral organs to cause as effect or action
the efferent or motor division is subdivided into the…
somatic nervous system and the autonomic nervous system
somatic nervous system supplies motor impulses to the…
skeletal muscles
autonomic nervous system supplies motor impulses to the…
cardiac muscle, smooth muscle, and glands
another name for the autonomic nervous system
visceral motor
the autonomic nervous system is further subdivided into…
sympathetic and parasympathetic divisions
enteric nervous system?
one of the main subdivisions of the autonomic nervous system and governs the function of the gastrointestinal tract
what are somatic senses:
touch, temperature, tickle, itch, pain, proprioception, pressure, vibration
what are special senses:
smell, sight, taste, hearing, balance
what are visceral senses:
pain, stretch of organ wall, blood pressure, pH of fluids within lumen, osmolarity of fluids
somatic motor?
voluntarily control of skeletal muscles
autonomic motor?
involuntarily control of smooth cardiac muscles
the brain consists of 4 structures which are
- cerebrum
- diencephalon
- cerebellum
- brainstem
the brainstem includes…
- the midbrain
- pons
- medulla oblongata
the CNS processes…
the incoming sensory and outgoing motor messages and is involved in higher mental activities such as learning memory, and reasoning
the nervous tissue in the CNS is organized as…
gray and white matter
gray matter comprises…
nerve cell bodies, bundles of unmyelinated nerve fibres, and non-neuronal supportive cells, the glial cells or neuroglia
white matter consists of…
bundles of myelinated nerve fibres known as tracts or fasciculi
in the spinal cord, the white matter surrounds…
the gray matter
in the brain, the gray matter surrounds…
the white matter
the outer shell of gray matter in the brain is called?
the cortex
what is a cluster of nerve cell bodies embedded within the CNS called?
nucleus
what is a cluster of nerve cell bodies outside the CNS called
ganglion
what are the two cells of the nervous tissue
neuroglia and neurons
what are neuroglia?
it support cells of the nervous system
nourish and clean up after neurons
lower order functions
what are neurons?
functional unit of nervous system
white matter inside the CNS are called?
tracts
white matter inside the PNS are called
nerves or fasciculus
what is the outermost layer of the brain?
cerebral cortex
the cerebral cortex is divided into…
right and left hemispheres
why is the cerebral cortex folded?
to increase surface area for information processing
what are the bumps/folds of the cortex called?
gyri
what are the grooves/indentations called?
sulci
what divides the hemispheres?
longitudinal fissure
what are the 4 main lobes?
frontal, parietal, occipital, temporal
what are some general functions of the frontal lobe?
cognition, control of voluntary movement, motor production of speech
what is the special sensation of the frontal lobe?
smell
what are the general functions of the parietal lobe?
processes sensory information
what is the special sensation of the parietal lobe?
taste
what are the general functions of the temporal lobe?
processes memories
what is the special sensation of the temporal lobe?
auditory information
what is the general function of the occipital lobe?
processing visual sensation
what is the special sensation of the occipital lobe?
sight
what is the central sulcus
the sulcus separating the parietal lobe from the frontal lobe
what is the lateral sulcus?
the sulcus separating the frontal and parietal lobes from the temporal lobe
what is the parieto-occipital sulcus?
the sulcus separating the parietal and occipital lobes
what are the clusters of nuclei within the white matter of the cerebrum called?
basal ganglia (nuclei)
what are the main components of the basal ganglia?
caudate and lenticular (putamen and globus pallidus) nuclei
- involved in coordination of motor function
what are the 3 groups of nerve bundles?
association fibres, commissural fibres, and projectional fibres
what are association fibres?
join the different parts of the same cerebral hemisphere
what are commissural fibres?
fibres that connect different gyri of one hemisphere to the corresponding gyri of the other hemisphere
what is the most extensive commissural fibre bundle
corpus callosum
where is the corpus callosum located?
at the bottom of the longitudinal fissure
what are projectional fibres
the ascending and descending fibres connecting the cortex to the lower centers of the CNS
what are the 3 major areas in each cerebral hemisphere?
- primary sensory areas
- primary motor area
- association areas
general idea about the primary sensory areas
from the receptor ->. ->. ->. ->
a course of peripheral nerve, a pathway (tract), thalamus, appropriate cortical area for the perception of the sense
where is the primary somatosensory area located?
the postcentral gyrus
where is the primary visual area located?
occipital lobe
where is the primary auditory area located?
upper portion of the temporal lobe
where is the primary gustatory area located? taste
insula (insular lobe)
where is the primary olfactory area located?
medial aspect of the temporal lobe
where is the insula located?
right under the lateral sulcus
where is the primary motor area located?
frontal lobe
where is the primary motor area specifically located?
precentral gyrus
what is the primary motor area responsible for?
conscious control of precise, skilled, voluntary movements
the primary motor area receives input from:
- premotor area and supplementary motor areas
- sensory cortex, thalamus, basal ganglia, and cerebellum
what is the motor homunculus (little man)
the motor control to different parts of the body comes from the appropriate part of the brain
the size of the body parts is ? to the degree of fine motor control allotted to those parts
proportional
where is the premotor area located?
located in the frontal lobe in front of the precentral gyrus
what is premotor area used for?
where you store your patterns of movement
where is the frontal eye field (FEF) located?
in front of the premotor area of the frontal lobe
what is the frontal eye field responsible for?
controls the voluntary, synchronized movement of the eyeballs
where is the Broca’s Area located?
at the inferior frontal gyrus of the frontal lobe
broca’s area is almost always found on which side of the brain?
left side of the brain
what is broca responsible for?
generating motor signals for the vocal apparatus
what happens when the broca’s area is injured?
the patient understands the speech but cannot speak
where is the wernicke’s area located?
around the posterior end of the lateral sulcus in the left temporoparietal junction
what is wernicke’s area responsible for?
understanding of language
what happens to someone with wernicke’s aphasia?
patient has empty, fluent speech and a loss of speech comprehension
what is the arcuate fasciculus?
the white matter tract that connected broca’s and wernicke’s area
what happens when the arcuate fasciculus is damaged?
conduction aphasia = difficulty repeating heard speech
what are association areas?
association areas are adjacent to the primary areas and are connected to the primary area by the association fibres
what is the somatosensory association area?
- located behind the primary somatosensory area in the parietal lobe
- integrates and interprets general sensations
- compares objects by their shapes and interprets the position of body parts relative to the rest of the body
- also stores information in long-term memory
what is astereognosis (astereognosia)
a lesion in the somatosensory association area that causes the inability to recognize an object placed in the hand
what is the visual association area
it surrounds the primary visual area in the occipital lobe and it gives meaning and interpretation to what we see
what is the auditory association area?
it 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
what is the common integrative area
- located among the sensory, visual, and auditory association areas
- integrates signals it receives from primary areas and 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
where is the diencephalon located?
between the cerebral hemispheres and the midbrain
what does the diencephalon include?
thalami, hypothalamus, and epithalamus
what is the thalamus and its function?
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
- the thalamus relays all sense except smell to certain sensory areas
what is the hypothalamus and its functions?
hypothalamus functions as the center of the autonomic nervous system, thus controlling emotions, body temperature, eating, drinking…etc.
- it also regulates the function of the major components of the endocrine system through the pituitary gland
what is the epithalamus?
it is a small region posterior and superior to the thalamus, mainly consisting of the pineal gland
what does the pineal gland do?
regulates the circadian rhythm and distribution of pigment melanin in the skin
what is the worm-like structure that connects the cerebellar hemispheres in the cerebellum?
vermis
what connects the brainstem to the cerebellum?
3 cerebellar peduncles
superior cerebellar peduncles?
carry axons that connect the cerebellum to the red nucleus of the midbrain and thalamus
middle cerebellar peduncles?
connect the pontine nuclei of the pons to the cerebellum
inferior cerebellar peduncles
carry bundles of axons travelling between the medulla and cerebellum, such as spinocerebellar tracts
what is interposed nucleus?
globose and ebnoliform together
what is folia?
the folds in the cerebellar cortex on the surface of the cerebellum
what are the primary function of the cerebellum?
coordination of voluntary movements and maintaining posture and balance
what is the brainstem composed of?
medulla oblongata, pons, and midbrain
what are the 3 major functions of the brainstem?
- acts as a passageway for all ascending and descending tracts between the cerebrum and spinal cord
- it contains the nuclei of the cranial nerves II to XII
- it regulates the automatic behaviours required for survival, such as respiration
what does the midbrain connect?
the pons and the diencephalon
What is the crus cerebri?
the columns on the anterior aspect of the midbrain
what is the superior and inferior colliculi?
located at the posterior aspect of the midbrain which is the relay center for the visual and auditory reflexes
what is the red nucleus?
associated with the rubrospinal tract as part of the extrapyramidal pathways
what is the substantia nigra
functionally linked to the basal ganglia regulating voluntary movements
what is the periaqueductal gray matter (PAG)
located around the cerebral aqueduct is a site of production of natural painkillers
what is the basilar sulcus?
the anterior surface of the pons and is occupied by the basilar artery
medulla oblongata is located where?
separated from the pons by the ponto-medullary sulcus and the spinal cord
what is the pyramid?
an elevation anteriorly on the medulla
what is the olive?
the lateral elevation of the medulla
what is at the junction of medulla and spinal cord?
decussation of pyramids
what is the reticular formation?
it is a collection of nuclei running vertically throughut the brainstem in 3 columns
how does the brain prevent sensory overload?
one of the reticular formations task is to filter out incoming sensory signals
list some of the functions of the reticular formation
- control of skeletal muscle
- pain modulation
- control of autonomic and endocrine systems
- circadian rhythms
- consciousness
what is the RAS system?
the reticular activating system responds to some stimuli, potentially disrupting a relatively constant flow and unchanged level of intensity of incoming signals
- a general anesthetics work to suppress this system
