martin chapter 1 Flashcards
functional neuroanatomy
examines those parts of the nervous system that work together to accomplish a specific task
regional neuroanatomy
eamines spatial relationships between brain structures within a portion of the nervous system
what are functional systems made of?
made by specific neural connections within and between regions of the nervous system, connections that form complex neural circuits
4 specialized regions that characterize each neuron
- dendrite
- cell body
- axon
4.axon terminal
which part of the neuron receives info from other neurons?
dendrites
what does the cell body contain?
the nucleus of neurons and organelles necessary for neuronal activity and survival. The cell body also receives info from other neurons
what do axons do?
conduct action potentials (informations) to the axon terminal
connections between two neurons in a circuit are made between?
the axon terminal of one neuron and the dendrites and cell body of another one
unipolar neurons
one single axon from the cell body, no dendrites
the least common ones in the human nervous system
bipolar neurons
2 processes
-one functions like a dendrite
-one functions like an axon
they’re under the category of pseudo unipolar neuron.
many sensory neurons are bipolar and pseudo unipolar neurons
multipolar neurons
one single axon
complex array of dendrites on the cell body
projection neurons
multipolar neurons with a very long axon that allows communication between different regions of the nervous system and between the nervous system and peripheral targets
interneurons
Multipolar neurons with short axons that remain in the same region in which the cell body is located. Help to process neuronal informations within a local brain region
communications from one neuron to another occur at specific sites called?
synapses
pre synaptic neuron
the neuron that sends the information
post synaptic neuron
the neuron that receives the information
3 main elements that compose a synapse
- pre synaptic terminal
- synaptic cleft
- receptive membrane of the postsynaptic neuron
what are the 2 neurotransmitters that excite neurons?
glutamate and acetylcholine
what are the 2 neurotransmitters that inhibit neurons?
GABA and glycine
in electrical synapses, there is what?
the cytoplasmic continuity between pre synaptic and post synaptic neurons.
macroglia, 4 types
Schwann cells (myelination of axons in the peripheral nervous system)
Oligodendrocytes (myelination of axons in the central nervous system)
astrocytes (important for the BBB, associated to synapses-regulate synaptic connections, important for neuronal development)
ependymal cells (lie the ventricles of the brain)
an oligodendrocyte can myelinate one or multiple axons at a time?
multiple axons at a time cause it has multiple processes
Schwann cells can myelinated one or multiple axons at a time?
one Schwann cell can myelinate one single axon
->one at a time
microglia
have a phagocytic role and are activated in response to different pathophysiological conditions. Activated microglia can destroy invading organisms. They can also change neuronal properties after tissue damage, hindering recovery.
for eg: after nervous system damage neurons become hyper excitable and microglia are mediator of this.
they also play a key role in modifying connections between neurons
neurons and glia cells are organized into 2 anatomically separated but functionally interdependent parts:
central nervous system
peripheral nervous system
the peripheral nervous system is subdivided in?
somatic
autonomic
enteric
the somatic division of the peripheral nervous system contains:
- sensory neurons that innervate skin, muscles and joints
- axons of motor neurons despite their cell body is in the CNS (motor neurons innervate skeletal muscles and regulate their force of contraction).
the autonomic division of the peripheral nervous system contains:
neurons that innervate glands and the smooth muscle of the viscera and blood vessels. Subdivided in sympathetic and parasympathetic
the enteric nervous system contains
neurons that innervate the GI tract
the central nervous system comprises
brain and spinal cord
the brain is subdivided in
cerebral hemisphere
diencephalon
midbrain
pons
cerebellum
medulla
within each of the 7 CNS divisions there is?
a component of the ventricular system
how are axons and cell bodies collected in the peripheral Nervous system?
cell bodies are collected in peripheral ganglia
axons are contained in peripheral nerves
in the central nervous system neuronal cell bodies and dendrites are located in?
- cortical areas, which are sheets of cells that are on the surface of the cerebral hemispheres
- nuclei, which are clusters of neurons beneath the surface of all the CNS divisions.
most common region that contains axons in the CNS is called?
tract
in fresh tissue, nuclei and cortical areas appear of which color?
grey
in fresh tissues, tract appear of which color? and why?
white due to the presence of myelin sheet
the spinal cord is made by multiple segments. each segment of the spinal cord is innervated by?
2 nerve roots and respective rootlets
1. dorsal root which contains sensory axons (transmit sensory infos to the spinal cord)
2. ventral root which contains motor axons (transmit motor commands to muscles and other body organs
the brain stem is composed of?
-midbrain
-medulla
-pons
what are cranial nerves?
sensory and motor nerve roots that enter and exit the brain stem
each of the three divisions of the brain stem are involved in the control of specific functions, such as:
the pons and the midbrain control eye movements
the medulla is involved in blood pressure and respiratory regulatory mechanisms
principal functions of the cerebellum
- control eye and limb movements
- mantain posture and balance
parts of the cerebellum play a role in higher brain functions (language, cognition and emotions)
2 principal parts of the diencephalon
thalamus and hypothalamus
key function of the thalamus
transmits informations to cerebral hemispheres. the thalamic nuclei transmit infos to cortical areas
thalamic adhesion, what is it?
formed when both parts of the thalamus come into contact at the midline
hypothalamus key functions
-controls the release of endocrine hormones from the pituitary gland
-controls the overall functions of the autonomic nervous system
hemisferes 4 main components
each hemisphere has 4 main components
1.cerebral cortex
2. basal ganglia
3. amigdala
4. hyppocampal formation
hippocampal formation main functions
important in learning and memory
amigdala main functions
take part in emotions but also in the coordination of the body response to threatening situations
what’s the name of the part that has the most complex shape in the basal ganglia?
the striatum
main functions of the basal ganglia
-cognition and emotion in concert with the cerebral cortex
-control of movement
area of the total human cerebral cortex
2500 cm2
what’s the name of the convolutions that characterize the cerebral cortex?
gyri, separated by sulci/fissures
the two cerebral hemispheres are separated one from each other by?
the sagittal fissure
4 lobes of the cerebral cortex, names:
-frontal
-parietal
-occipital
-temporal
the pre central gyrus and the post central gyrus are separated by?
the central sulcus
the primary motor cortex is contained in?
the pre central gyrus
the Broca’s area in most people is contained in?
the inferior frontal gyrus
association cortical areas
present in all lobes, essential to process informations for higher brain functions
basal forebrain
on the ventral surface of the frontal lobe
contains neurons that use acetylcholine to regulate cortical excitability
where is the olfactory bulb located?
in the ventral surface of the frontal lobe
superior and inferior parietal lobules are separated by?
the intraparietal sulcus
the primary somatic sensory cortex is located?
in the post central gyrus
what separates the frontal lobe from the parietal lobe?
the central sulcus
what separates the parietal lobe from the occipital lobe?
parietooccipital sulcus
what’s the main function of the occipital lobe?
controls vision
where is the primary visual cortex located?
in the calcarine fissure, responsible for the initial stages of visual processing
the temporal lobe is separated from the frontal and the parietal lobe by?
the lateral sulcus or sylvian fissure
where is the primary auditory cortex located?
in the superior temporal gyrus
the insular cortex
is buried deep in the lateral sulcus and contains portion of the parietal, temporal and frontal lobes
corpus callosum
-largest of the brain’s commissures
-contains axons that connect both sides of the cortex
-integrates the functions of the 2 halves of the brain
4 main parts of the corpus callosum
- splenium->the informations between the occipital lobes travel through the splenium
- rostrum
- body
- genu
informations from all the other lobes travel from these other 3 parts
what is a commissure?
a tract that contains axons that interconnects the two sides of the brain
cerebrospinal fluid
-contained in the ventricular system
-cushions the CNS from physical shock and is a medium for chemical communication
-the choroid plexus contains most of the CSF
ventricles
two lateral ventricles one on each hemisphere
the third ventricle is between the two halves of the diencephalon
the 4th ventricle is between the cerebellum and the brain stem
the ventricular system enters the spinal cord through
the central canal
each lateral ventricle is connected with the 3rd ventricle by?
the interventricular foramina
the 3rd and 4th ventricles are connected by?
the cerebral aqueduct
name of the frontal, parietal and temporal cortices that cover the insular cortex are named?
opercula
meninges are composed of
dura mater
arachnoid mater
pia mater
2 structures arise from the dura
falx cerebri, which separates 2 cerebral hemispheres
tentorium cerebelli, which separates the cerebellum from the hemispheres
the subdural space is between?
dura and arachnoid
the arachnoid mater joins the dura but is not tightly bonded allowing the subdural space to exist
