chapter 3 Flashcards
CNS
the division of the nervous system located within the skull and spine
PNS
the division located outside the skull and spine
Somatic nervous system
part of the PNS that interacts with the external environment
composed of afferent and efferent neurons
Autonomic nervous system
part of the peripheral nervous system that regulates the body’s internal environment
Afferent Nerves
carry sensory signals from the skin,skeletal muscles,joints,eyes,ears and so on
Efferent nerves
carry motor signals from the ventral nervous system to the skeletal muscles
Sympathetic nervous system
sympathetic nerves stimulate,organize and mobilize energy resource in threatening situations
fight or flight
Parasympathetic Nervous System
autonomic target organ receives opposing sympathetic activity
changes are indicative of psychological relaxation
Meninges: Dura,Pia, Arachnoid
Protective membranes
Dura - tough membrane
Arachnoid - fine spider-web-like membrane
Pia - delicate , which adheres to the surface of the CNS
Cerebrospinal fluid (CSF)
also protecting the CNS
fills the subarachnoid space, the central canal of the spinal cord and the cerebral ventricles of the brain
cerebral ventricles (lateral, 3rd, 4th)
four large internal chambers of the brain
the two lateral ventricles
the third ventricle and the fourth ventricle
cerebral aqueduct
connects the third and fourth ventricles
choroid plexus
networks of capillaries, or small blood vessels that protrude into the ventricles from the pia mater
cerebrospinal is produced
neurons
cells that are specialized for the reception,conduction and transmission of electrochemical signals
glial cells
Any of the cells that hold nerve cells in place and help them work the way they should.
oligodendrocytes
glial cells with extensions that wrap around the axons of some neurons of the central nervous system
- CNS
Schwann Cells
performed in the peripheral nervous system
each Schwann cell constitutes one myelin segment
wrap around with myelin
astrocytes
largest glial cells
extensions of some astrocytes cover the outer surfaces of blood vessels that course through the brain
play a role in allowing the passage of some chemicals from the blood into CNS neurons and blocking other chemicals
they have the ability to contract or relax blood vessels based on the blood flow demands of particular brain regions
microglia
smaller than other glial cells
respond to injury or disease by multiplying, engulfing cellular debris or even entire cells and triggering inflammatory responses
nuclei ganglia
in CNS
clusters of cell bodies
Ganglia
in the PNS
clusters of cell bodies
tracts/nerves
anterior
towards the nose end
posterior
toward the tail end
dorsal
toward the surface of the back or the top of the dead
ventral
toward the surface of the chest or the bottom of the head
medial
toward the midline of the body
lateral
away from the midline toward the body’s lateral surfaces
superior
above
towards the head
inferior
below
towards the ground
proximal
close
distal
far
planes: frontal,horizontal,sagittal
the brain gets cut in one of three different planes
grey matter
composed largely of cell bodies and unmyelinated interneurons
white matter
composed largely of myelinated axons
tectum
Tectum - composed of two pairs of bumps = inferior coliculi (posterior) and superior colliculi (anterior)
Inferior coliculi = auditory function
Superior colliculi = visual-motor function
contralateral/ipsilateral
contralateral = opposite side
Ispilateral = same side
fissures,slci,gyri
The deep furrows are called fissures
shallow ones are called sulci (singluar; sulcus).
The ridges between the sulci are known as a gyri (singular; gyrus).
telencephalon
the largest division of the human brain
mediates the brain’s most complex functions
initiates voluntary movement, interprets sensory input and mediates complex cognitive processes such as learning, speaking and problem solving
diencephalon
composed of two structures: the thalamus and the hypothalamus
thalamus - relay station in the visual, auditory and somatosensory systems
hypothalamus - regulation of several motivated behaviors (eating,sleep and sexual behavior)
mesencephalon
made up of the tectum and the tegmentum
Tectum - dorsal surface of the midbrain
Tegmentum - division of the mesencephalon ventral to the tectum
metencephalon
houses many ascending and descending tracts and part of the reticular formation
contain the pons, cerebellum
myelencephalon(medulla)
the most posterior division of the brain, composed largely of tracts carrying signals between the rest of the brain and the body
contains the reticular formation
reticular formation
a complex network of about 100 tiny nuclei that occupies the central core of the brain stem from the posterior boundary of the myelencephalon to the anterior boundary of the midbrain
functions - sleep,attention, movement, the maintenance of muscle ton, and various cardiac, circulatory, and respiratory reflexes
*arousal
pons
a bulge on the brain stem’s ventral surface
handles unconscious processes and jobs, such as your sleep-wake cycle and breathing
cerebellum
convoluted structure on the brain stem’s dorsal surface
it is an important sensorimotor structure
cerebellar damage eliminates the ability to precisely control one’s movements and to adapt them to changing conditions
however, the fact that cerebellar damage also produces a variety of cognitive deficits
inferior and superior colliculi
inferior = auditory function
superior = visual-motor function, specifically to direct the body’s orientation toward or away from particular visual stimuli
periaqueductal gray
the gray matter situated around the cerebral aqueduct, the duct connecting the third and fourth ventricles
substantia nigra
black substance
important components of the sensorimotor system
red nucleus
important components of the sensorimotor system
thalamus
large, two-lobed structure that constitutes the top of the brain stem
one lobe sits on each side of the thrid ventricle and the two lobes are joined by the massa intermedia
thalamic nuclei are the sensory relay nucli and then transmit them to the appropriate areas of sensory cortex
massa intermedia
joins the two lobes of the thalamus
runs through the ventricle
visible on the surface of the thalamus are white lamina (layers) that are composed of myelinated axons
lateral and medial geniculate nuclei
are important relay stations in the visual and auditory systems
hypothalamus
located just below the anterior thalamus
important role in the regulation of several motivated behaviors ( eating, sleep and sexual behavior)
it exerts its effects in part by regulating the release of hormones from the pituitary gland
pituitary gland
dangles from the hypothalamus
regulates the release of hormones
optic chiasm
the point at which the optic nerves from each eye come together
the X shape is created because some of the axons of the optic nerve decussate (cross over to the other side of the brain) via the optic chiasm
mammillary body
considered to be part of the hypothalamus
pair of spherical nuclei located on the inferior surface of the hypothalamus, just behind the pituitary
recollective memory
cerebral cortex
cerebral hemisphere are covered by a layer to tissue called the cerebral cortext
fissures,sulci,gyri
fissure - large furrows in a convoluted cortex
sulci - small ones
gyri- ridges between fissures and sulci
longitudinal fissure,central fissure and lateral fissure
Longitudinal fissure - cerebral hemisphere almost completely separated by the largest of the fissures
Central fissure - seperate the frontal and parietal lobe
Lateral fissure - superate temporal lobe and Frontal + Parietal
cerebral commissures: corpus callosum
hemisphere connecting tacts = cerebral commissures
the largest cerebral commissure is the corpus callosum
precentral and postcentral gyrus
large gyri for the central fissure
superior temporal gyrus
bellow the lateral fissure
frontal lobe
pre-central gyrus and adjacent frontal cortex have a motor function
whereas the frontal cortex anterior to motor cortex performs complex cognitive functions such as planning response sequences, evaluating the outcomes of potential patterns of behavior and assessing the significance of the behavior of others
parietal lobe
postcentral gyrus analyzes sensations from the body, whereas the remaining areas of cortex in the posterior parts of the parietal lobes play roles in perceiving the location o both objects and our own bodies and in directing our attention
temporal lobe
the superior temporal gyrus is involved in hearing and language
the inferior temporal cortex identifies complex visual patterns
the medial portion of the temporal cortex (which is not visible from the usual side view) is important for certain kinds of memory
occipital lobe
analysis of visual input to guide our behavior
hippocampus
this folding produces a shape that is,in cross-section, somewhat reminiscent of a seahorse
the hippocampus plays a major role in some kinds of memory, particularly memory for spatial location
limbic system
circuit of midline structures that circle the thalamus (limbic means “ring”)
the limbic system is involved in the regulation of motivated behaviors - including the four F’s of motivation
fleeing
feeding
fighting
sexual behavior
amygdala
an almond-shaped nucleus in the anterior temporal lobe
the perception of emotions such as anger, fear, and sadness, as well as the controlling of aggression
cingulate cortex
the large strip of cortex in the cingulate gyrus on the medial surface of the cerebral hemispheres, just superior to the corpus callosum; it encircles the dorsal thalamus
cingulate gyrus
an arch-shaped convolution situated just above the corpus callosum.
fornix
the major tract of the limbic system also encircles the dorsal thalamus; it leaves the dorsal end of the hippocampus and sweeps forward in an arc coursing along the superior surface of the third ventricle and terminating in the septum and mammillary bodies
basal ganglia
amygdala, striatum and globus pallidus
caudate
long tail-like
sweeping out of each amygdala, first in a posterior direction and then in an anterior direction
each one forms an almost complete circle; in its center connected to it by a series of fiber bridges
parkinson’s disease
a disorder characterized by rigidity, tremors and poverty of voluntary movement is associated with the deterioration of this pathway (basal ganglia)
tegmentum
division of the mesencephalon ventral to the tectum
reticular formation and tracts of passage
contains the periaqueductal gray,substantia nigra and the red nucleus
striatum
together the caudate and the putamen, which both have a stripped appearance
globus pallidus
the remaining structure of the basal ganglia is the pale circular structure known as the globus pallidus
located medial to the putamen between the putamen and the thalamus
