73 terms

The Brain

the brain
this major structure is 3 pounds (approximately 2% of the body weight)
uses 20% of the body's oxygen
and is composed of 100 billion multipolar neurons and 1 trillion neuroglia
cerebrum, cerebellum, diencephalon, brain stem
what are the four major parts of the brain
major part of the brain that is the largest part
major part of the brain that contains integration centers for receiving and interpreting sensory information
major part of the brain that contains the integration center for generating and controlling muscle movements
major part of the brain that contains integration centers for providing mental functions such as memory, intellect, creativity, and reasoning
major part of the brain that is the 2nd largest part
major part of the brain that contains the integration centers that coordinate and fine tune voluntary muscles movements
major part of the brain that is the physical center of the brain
major part of the brain that contains relay and integration centers for incoming sensory information
major part of the brain that integrates nervous system and endocrine system
brain stem
major part of the brain that is the "trunk of the brain"
brain stem
major part of the brain that connects parts of the brain to spinal cord
brain stem
major part of the brain that contains integration centers that regulate visceral (autonomic) activities
cranial bones, cranial meninges, cerebral spinal fluid
what are the three things that protect brain tissue ?
cranial meninges
this brain tissue protector is made of three membrane layers that surround the brain. they are continuous with the spinal meninges
dura, arachnoid, pia
what are the three cranial meninges
endosteal, meningeal
what are the two layers of dura mater?
this layer of dura mater forms the inner periosteum of the cranium
it is the outer layer
layer of dura mater that forms the inner layer. it forms the dural sinus. There is a collecting vein located between 2 layers. There is collecting cerebrospinal fluid and return it to the blood.
arachnoid membrane, arachnoid trabeculae
what are the two layers of the arachnoid mater?
arachnoid membrane
layer of arachnoid mater that is the epithelial layer
arachnoid trabeculae
layer of arachnoid mater that extends across subarachnoid space to the pia mater
pia mater
inner layer of the cranial meninges that holds cerebral blood vessels in place
arachnoid granulations
these are extensions of the arachnoid layer into the dural sinuses. it forms an opening for CSP to drain into dural sinuses
dural folds
these are folds of dura mater that extend deep into the brain
dural folds
these function in separating parts of the brain and anchors and supports the brain in the cranium
dural folds
these function in containing the dural sinuses that collect CSF and return into the blood stream.
these are a series of 4 interconnecting chambers in the brain
choroid plexus
lining of ependymal cells that separate CSP
lateral ventricles
venticles 1 and 2. each ins located in each cerebral hemisphere
ventricle located in diencephalon
ventricle located in brain stem
connects with the central canal of the spinal cord
brain stem
this part of brain is considered the primitive brain or the trunk of the brain
brain stem
this part of the brain connects all parts of the brain to the spinal cord
medulla oblongata, pons, midbrain
what are the three parts of the brain stem
medulla oblongata
this part of the brain stem is most inferior.
medulla oblongata
this part of the brain stem is a continuation of spinal cord at foramen magnum
contains many integration centers (nuclei) for maintaining homeostasis
-relay stations (tracts), reflex centers (nuclei), integration centers
relay station, reflex center
what tracts do the medulla oblongata contain?
relay stations
all ascending and descending spinal tracts pass through it
-relay sensory/motor info b/t the spinal cord & brain
-central canal opens into the 4th ventricle
reflex center
has two centers: cardiovascular and respiratory
center of reflex center that controls rate and force of heart contractions
center of reflex center that controls rhythm of breathing
integration center
this part of medulla oblongata processes sensory and motor commands that innervate the throat, neck, back, and digestive organs
this is an anterior bulge, superior to the medulla
relay station, integration center
these are the two functions of the pons
relay station
this function of the pons relays information between cerebellum, brain stem, cerebrum, and the spinal cord
integration center
this function of the pons is sensory and motoe control of the jaws anf face
this is the most superior part of brain stem that connects to the diencephalon
relay station
function of midbrain of the descending tracts that relay voluntary motor commands from cerebral cortex to the PNS and cerebellum
reflex station
function of midbrain that initiates reflex movement of the eye, head, neck, and trunk in response to visual and auditory stimuli
reticular activating system
function of midbrain that maintains consciousness and awakening by alerting the cerebral cortex of incoming stimuli
Adjusts postural muscles
function of cerebellum that eceives info from: proproceptors, visual and tactile receptors, inner ear
-coordinates rapid, autonomic adjustments that maintain BALANCE and POSTURE
Fine-tunes movements
function of cerebellum that refines learned movement patterns by:
-monitoring motor commands from the cerebral cortex & brain stem
-comparing this motor info w/ proprioceptor info
-making adjustments to insure smooth movements
a disturbance in muscle coordination
-the result of trauma, stroke, or chemical influences to the CEREBELLUM
-causes twitchiness and lack of coordination
thalamus, hypothalamus, epithalamus
what are the three parts of the diencephalon
roof of diencephalon & third ventricle
-contains a choroid plexus
-houses the pineal gland, which secretes melatonin
left and right, forms the walls of the diencephalon,
-final relay station for sensory impulses arriving along ascending tracts of the spinal cord
thalamic nuclei
filter incoming sensory info & relay it to the appropriate region of the cerebral cortex of further processing
forms the floor of the diencephalon
-regulates cardiovascular & respiratory centers of the pons and medulla
-regulates body tempurature
-controls reflexive responses to emotions as part of the limbic system
-controls conscious and unconscious behaviors(unconscious need for water becomes thirst)
-integrates the nervous and endocrine systems
-a stalk-like structure, the infundibulum connects the hypothalamus to the pituitary gland (the master endocrine gland)
-mamillary bodies
mamillary bodies
process olfactory sensation
-cotrol reflexes of chewing,licking , swallowing
white matter
makes up most of cerebrum, deep in cortex, consists of myelinated axon fibers
association fibers
type of white matter that interconnected areas of a SINGLE hemisphere, such as lobes or gyri
type of white matter that interconnected w/ the 2 hemispheres
-corpus callosum- above diencephalon
-anterior commissure- connects frontal lobes
type of white matter that connect the cerebrum w/ the lower brain structures: diencephalon, brain stem, spinal cord
gray matter
this type of matter is found in 2 areas
Cerebral Cortex
superficial covering of gray matter where all high-level integration occurs
basal nuclei
areas of gray matter deep within the cerebral hemispheres, coordinate the unconscious movement of skeletal muscle: -repeated movements of muscles (walking) -contains stabilizing muscles of trunk
Primary Sensory Cortex
receives sensory info from the thalamus, passes info to other association areas before motor responses are generated
primary motor cortex
initiates motor impulses to voluntary (skeletal) muscles, impulses are modified in other association areas before being directed down the spinal cord
association areas
located in various lobes of the cortex, areas of cortex that analyze + interpret info. from the primary sensory and motor cortexes,

- of the Frontal lobe- contain the primary MOTOR cortex, control higher intellectual processes (concentration, planning, judgement)

- of the Parietal Lobes- contain primary SENSORY cortex, interpret speech and control the selection

- of the Occipital Lobes- visual cortex- interpret VISUAL sensations from the retina of the eye

-of the Temporal Lobes- auditory cortex- interpret auditory sensations from the ear, olfactory cortex- interpret odor sensations from the nasal cavity
limbic system
functional group of nuclei and tracts, located along the boarder of the cerebrum and diencephalon, influences the ENDOCRINE system
-also known as the motivational system, pleasure center of the brain, responsible for emotions of (fear, pain, rage, sexual arousal +pleasure)
limbic system
1. establishes emotional states
2. links conscious (cortex) and unconscious (brainstem) functions
3.memory storage + retrieval