Overview of the nervous system Flashcards
What can the human nervous system be broken down into?
the central nervous system and peripheral nervous system
What does the central nervous system consist of?
the brain and the spinal cord
What is the brain?
a bunch of several structures that include the cerebrum (the left and right hemisphere), the spinal cord, and the cerebellum
What is the cranium?
the place that encases or holds the brain
What is the spinal cord?
part of the brain; it connects the brain and body; the brainstem that passes through the foramen magnum
What is gray matter?
cell bodies or nuclei that process information in the brain; it makes up the cortex or outer layer of the brain; look dark in dissections
What is white matter?
extensions of the gray matter that transmit signals from one cell to another; A.K.A CNS tissues made up of axons that are covered by myelin; Appears light in dissection.
What structures protect the brain and spinal cord?
cerebrospinal fluid, meninges, and bony encasing
What is CSF?
fluid found in the ventricles of the brain and spinal cord; it protects and nourishes the brain
What are the meninges?
set of 3 tissue layers that cover the brain and spinal cord and have space for CSF to be in
The _____ protects the brain and the ______ protects the spinal cord.
cranium; vertebral column
What is the PNS?
nerves that leave the brain and spinal cord and go to the body’s muscles, tissues, and organs in order to innervate them.
What nerves make up the PNS?
12 cranial nerves that innervate the head and neck and 31 pairs of spinal nerves that innervate body parts below the neck
What can the PNS be divided into?
autonomic and somatic
What is the autonomic nervous system?
one part of the peripheral nervous responsible for unconscious control of body systems. Has two parts: sympathetic or fight or flight and parasympathetic (Rest and digest)
What is the somatic nervous system?
One part of the peripheral nervous system responsible for voluntary body movements and bodily sensation.
What three areas does the cortex (outer layer of the brain) consist of?
primary, secondary (association), and tertiary (heteromodal)
What is somatotopy?
a term that describes the arrangement of primary motor and sensory areas; these areas are organized by the parts of the body (soma) that they control.
Why are the hands, lips, and mouth of the homunculus so big?
There are many brain cells controlling those areas.
What is tonotopy?
a term used to state that the regions within the auditory system are organized based on the pitch of a sound.
What is retinotopy?
a term used to state that regions in the visual cortex are arranged based on where the image hits the retina.
What is a gyrus?
a hill or ridge; a.k.a convolution (plural form is gyri)
What is a sulcus?
valley or enfolding (plural form is sulci)
What is a fissure?
a valley or enfolding; usually deeper than a sulcus
What is cortex?
outer layer of gray matter that covers the hemispheres
What is a nucleus?
bunch of cell bodies; a term used to describe structures in the central nervous system; plural form is nuclei
What is a ganglion?
bunch of cell bodies; term used to describe structures in the peripheral nervous system; plural form is ganglia
What is a fasciculus?
a group of axons
What is a commissure?
band of fibers/axons that connect the two sides of the nervous system
What is a projection tract?
group of axons that begin in the brain and extend outside of it, such as the spinal cord
What is an association tract?
group of axons within the hemisphere; they connect lobes to each other or gyri to each other within a lobe
What are the two categories of cells in the nervous system?
neurons and glial cells
What do glial cells do?
they provide structure, protection, and management of waste
What are the parts of a neuron?
soma or cell body, dendrites, axon, axon hillock, axon terminal,
What is a synapse?
The point where neurons communicate
______ are the areas that are the core and initial location of processing
Primary areas
_______ are the areas where further processing of input occurs; multiple aspects of signals and integration across modalities is combined.
Secondary (association) areas
______ are the areas that are characterized by multimodal inputs and functions, such as the prefrontal cortex.
Tertiary (heteromodal) areas
What landmark in the brain separates the left and right hemispheres?
sagital sulcus a.k.a. longitudinal fissure
What lobes does the sylvian fissure a.k.a lateral sulcues separate?
temporal lobe inferiorly from the frontal lobes and superiorly from the parietal lobes
Deep in the sylvian fissure is the ________
insula
What landmarks are on the lateral surface of the brain?
central sulcus or sulcus of Rolando; sylvian fissure; insula; pre-central gyrus and post-central gyrus
What landmarks are on the medial surface of the brain?
cingulate gyrus, thalamus, corpus callosum, septum pellucidum, hypothalamus, calcarine sulcus
What are the three regions that the frontal lobes are divided by functionally?
anterior or prefrontal region (a.k.a. prefrontal cortex); posterior frontal region; posterior part of the inferior frontal gyrus or the frontal operculum
What is the function of the prefrontal cortex?
executive functions, such as working memory, problem-solving, reasoning, and planning
What is the function of the posterior region of the frontal lobe?
Has the motor cortices (supplementary motor areas, premotor area, and primary motor area)
What is the function of posterior portion of the inferior frontal gyrus?
basic language expression
Where is the primary motor area found?
within the pre-central gyrus
What are the functions of the parietal lobes?
awareness of one’s body in space; processing of senses and attention; awareness of one’s body i.e. knowing that you are tall or short, fat or skinny, etc.
What is one function of the temporal lobe?
language comprehension
What is the primary function of the basal ganglia?
motor control
The _______ is the primary auditory processing area.
transverse gyrus or Heschl gyrus, located in the anterior portion of the superior temporal gyrus
Where is the hippocampus located? What is its function?
Deep to the parahippocampal gyrus in the medial region; it turns short-term memory into long-term memory.
What is the fusiform gyrus, where it is located, and what is its purpose?
Also known as the occipotemporal gyrus, it is located on the inferior surface of the temporal lobe. It is important for visual processing, particularly for faces
What are the two areas found in the temporo-parietal-occiptal area? What purpose do they serve?
Angular gyrus and supramarginal gyrus; they integrate signals from the language areas of the temporal lobe and visual signals from the occipital lobe to aid in visual language, namely reading and writing
What is the function of the occipital lobes?
visual processing at the occipital poles and around the calcarine sulcus
What does the calcarine sulcus do?
It divides the occipital lobe into superior and inferior sections
What are the subcortical structures of the brain?
basal ganglia and thalamus
What are the major structures of the basal ganglia?
subthalamic nuclei, caudate nucleus, globus pallidus, substantia nigra, and putamen
What parts of the CNS is the basal ganglia connected to?
sensory areas of the CNS; brainstem; cerebellum; other motor areas such as the pre-central gyrus
What attaches the cerebellum to the brainstem?
peduncles - these send signals to and from the cerebellum
What role does the thalamus play in the CNS?
it is an area where most sensory signals, except for smell, synapse. It is connected to most regions in the CNS; thus, it plays a role in hunger, hormonal control, sleep/wake cycles, and cortical control.
What are folia?
Sulci and gyri in the cerebellum
What are the functions of the cerebellum?
coordinating movement, maintaining balance, motor learning, and vision
What are the three parts of the brainstem?
midbrain, pons, and medulla oblongata
What role does the brainstem play?
plays a role in automatic and life sustaining functions; places where cranial nerves that are important to speech and swallowing are housed.
