Central Nervous System Flashcards
The parts of Brains Regions are
Cerebrum - cerebral
hemispheres
Diencephalon –
hypothalamus,
thalamus, epithalamus
Brainstem
Cerebellum
What Consists of midbrain, pons, and medulla oblongata Spinal cord continuous with medulla oblongata?
Brainstem
What? elevated ridges of tissue
• _____ – motor area
• _____ – somatosensory area
Gyrus
Precentral gyrus
Postcentral gyrus
What shallow groove separating gyrus
• ______– separates frontal from parietal lobe
• Lateral sulcus – separates temporal lobe from parietal and
frontal
Sulcus
Central sulcus
deep grooves separating brain regions
• _____ – separates hemispheres
• _______ – separates cerebrum from cerebellum
Fissures
Longitudinal
Transverse
What Divided into 2 halves
cerebral hemispheres
What Divided into 2 halves
cerebral hemispheres
The cerebral hemispheres composed of 3 layers
1.Cerebral cortex - outer layer of gray matter associated with consciousness
(voluntary behavior)
2. Cerebral white matter – communication between cerebral areas and
cortex to lower CNS centers
• Ex. Corpus callosum connects 2 hemispheres integrating information
3. Basal Nuclei (ganglia) -Core of gray matter that controls subconscious
contractions of skeletal muscle
outer layer of gray matter associated with consciousness
voluntary behavior
Cerebral cortex
communication between cerebral areas and
cortex to lower CNS centers
Cerebral white matter
communication between cerebral areas and
cortex to lower CNS centers
Cerebral white matter
-Core of gray matter that controls subconscious
contractions of skeletal muscle
Basal Nuclei (ganglia)
-Core of gray matter that controls subconscious
contractions of skeletal muscle
Basal Nuclei (ganglia)
The Brain Anatomically divided into 4 major lobes – ________________ covered by parts of the
temporal, frontal and parietal lobes
frontal, parietal,
occipital, temporal and the insula
The Brain Anatomically divided into 4 major lobes – ________________ covered by parts of the
temporal, frontal and parietal lobes
frontal, parietal,
occipital, temporal and the insula
Controls voluntary movement
& located in posterior part of frontal lobe
Motor Area
Controls voluntary movement
& located in posterior part of frontal lobe
Motor Area
Receive sensory information
& Involved in perception – conscious awareness
of a sensation
Sensory area
Receive sensory information
& Involved in perception – conscious awareness
of a sensation
Sensory area
Located in precentral gyrus of frontal lobe
& Controls skeletal muscle movement
Primary motor cortex
Located in inferior/lateral area of frontal lobe
.Controls muscles of tongue, throat and lips to form
words
• Most people – on left side
Broca’s area (motor speech area)
• Receives sensory information from skin and skeletal muscles
and identifies part of body being stimulated – called spatial
discrimination
• Integrates and analyzes different sensory inputs and evaluates
what is being felt
• Receives information on joint and muscle position –
Proprioception
Primary somatosensory area - in postcentral gyrus of parietal
lobe
- Receives impulses for taste
* Involved in gustatory (taste) perception
Gustatory cortex – located at base of precentral gyrus on the
insula lobe
posterior occipital lobe
• Receives visual information from retinas
• Interprets and evaluates visual stimuli
Visual area
superior temporal lobe
. Auditory stimuli from cochlea evaluated for pitch, rhythm,
loudness
• Identifies sound
Auditory area
superior temporal lobe
. Auditory stimuli from cochlea evaluated for pitch, rhythm,
loudness
• Identifies sound
Auditory area
medial aspect of temporal lobe
• Conscious awareness of odors
Olfactory cortex
DIENCEPHALON
Extends from brainstem to cerebrum
• Surrounds 3rd ventricle
• Includes thalamus, hypothalamus, epithalamus
Bilateral masses of gray matter in center of brain
• Functions include:
• Relay station for all sensory impulses and relayed to
appropriate area
• Transmits motor information from cerebellum to primary
motor area
THALAMUS
Superior to the thalamus, extends posteriorly superior to
the cerebellum as the Pineal Gland.
The Pineal Gland induces sleep when it becomes dark thus
it plays a role in regulating circadian rhythms.
EPITHALAMUS
HYPOTHALAMUS
Inferior to thalamus
HYPOTHALAMUS Functions include:
. Control of autonomic nervous system to regulate homeostasis
• Initiates physical response to emotions – increased heart rate, etc.
when scared
• Regulates body temperature
• Regulates food and water intake
• Regulates sleep-wake cycle
• Controls endocrine function by producing hormones that act on
pituitary gland
BRAINSTEM
Three sections:
• Midbrain – inferior to diencephalon
• Pons – superior to medulla, anterior to cerebellum
• Medulla oblongata – most inferior part that is
continuous inferiorly with spinal cord
• Midbrain – inferior to diencephalon
• Pons – superior to medulla, anterior to cerebellum
• Medulla oblongata – most inferior part that is
continuous inferiorly with spinal cord
MIDBRAIN
regulates normal rhythm of
breathing; Aids the medulla oblongata with controlling
respiratory functions
Pneumotaxic center (PONS)
Hypothalamus relays instructions through medulla for visceral
function
Controls reflexes for vomiting, sneezing, swallowing,
hiccups, etc. (autonomic reflexes
MEDULLA OBLONGATA
regulates heart beat and blood
pressure
Cardiovascular center
generates respiratory rate
Respiratory center
Located posterior to pons and medulla, inferior to
occipital lobe
• Contains inner layer of white matter tracts called arbor
vitae – white matter tracts and fibers within the
cerebellum
CEREBELLUM
CEREBELLUM Functions:
• Provide smooth coordinated movements of skeletal
muscles
• Regulates posture and balance
• encircles midbrain and corpus callosum
• Center for emotions (pain or pleasure centers),
memory and olfaction
Limbic system
Located throughout brainstem
• Contains the RAS which maintain consciousness, active
during awakening
• Filters out repetitive stimuli
Reticular formation
. Meninges – 3 connective tissue membranes that cover
and protect CNS
• Cerebrospinal fluid (CSF) – liquid cushion for CNS
• Blood Brain Barrier - maintains stable environment of
brain
PROTECTION OF BRAIN
3 connective tissue membranes that cover
and protect CNS
Meninges
liquid cushion for CNS
Cerebrospinal fluid (CSF)
maintains stable environment of
brain
Blood Brain Barrier
Define MENINGES
Dura mater, Arachnoid mater, pia mater.
ough double-layered outer membrane
• Outer layer connects to crista galli of ethmoid
• head trauma can cause bleed into Subdural space (between dura and arachnoid mater
Dura mater
spidery middle layer
• Subarachnoid space – filled with CSF
Arachnoid mater
“gentle mother”
• attached directly to brain
• Highly vascular
Pia mater
Colorless fluid surrounding brain and spinal cord
Contains water, glucose, albumin, gases (oxygen and
carbon dioxide) and metabolic wastes (urea, creatine)
CEREBROSPINAL FLUID (CSF)
• No red blood cells or platelets, some white blood cells
(lymphocytes and monocytes)
• Provides buoyancy to reduce brain weight
CEREBROSPINAL FLUID (CSF)
• Cushions and nourishes nervous tissue
• Produced by choroid plexus that hang from roof of
ventricles (cavities in brain)
CEREBROSPINAL FLUID (CSF)
Brain capillaries impermeable to most substances due to the
presence of astrocytes.
BLOOD BRAIN BARRIER
Control chemical environment around neurons
• allows nutrients (glucose, amino acids)
• Lipid soluble substances can also enter – oxygen, carbon
dioxide, fats, alcohol, nicotine, anesthetics
BLOOD BRAIN BARRIER
GENERAL FUNCTIONS OF SPINAL
CORD
- Provides two way conduction pathway to and from brain
- Initiates complex patterns of motor activities like walking
- Major reflex center
GROSS ANATOMY
Vertebrae – bone surrounding spinal cord
• Meninges – connective tissue coverings that protect
spinal cord
• Spinal cord – nervous tissue
bone surrounding spinal cord
Vertebrae
connective tissue coverings that protect
spinal cord
Meninges
nervous tissue
Spinal cord
- Surround and protect spinal cord
* 31 pairs of spinal nerves exit via intervertebral foramen
VERTEBRAE
space between vertebra and dura mater filled with
fat and blood vessels
(Cushions and protects spinal cord from
vertebra)
Epidural space
SPINAL CORD
• Contains gray and white matter
• Roots - sensory and motor axons that exit spinal cord via
intervertebral foramen
• Central canal – cavity in center of gray matter that
contains CSF
• Cord ends around L1 – spinal taps done below L3
• Cauda equina – lumbar and sacral nerve roots at end of
spinal cord
Knowing the difference between Gray and White matter
• Gray matter is butterfly shaped area containing
unmyelinated multipolar neurons
• White matter – myelinated nerve fibers surrounding
gray matter carry information up and down to the brain
sensory and motor axons that exit spinal cord via
intervertebral foramen
Roots
cavity in center of gray matter that
contains CSF
Central canal
Cord ends around L1
spinal taps done below L3
lumbar and sacral nerve roots at end of
spinal cord
Cauda equina
GRAY MATTER
• Ventral (anterior) horn – contains cell bodies of somatic
motor neurons
• Lateral horns – contain autonomic motor neurons cell
bodies that serve visceral organs (only in thoracic and upper
lumbar)
• Dorsal (posterior) horn – contains cell bodies of
association neurons
• ** Sensory neuron cell bodies are outside the spinal cord in
the Dorsal (posterior) root ganglion**
contains cell bodies of somatic
motor neurons
Ventral (anterior) horn
contain autonomic motor neurons cell
bodies that serve visceral organs (only in thoracic and upper
lumbar)
Lateral horns
contains cell bodies of
association neurons
Dorsal (posterior) horn
Sensory neuron cell bodies are outside the spinal cord in
the ________?
Dorsal (posterior) root ganglion**
WHITE MATTER
• Ascending tracts– sensory axons running up to brain
• Descending tracts– motor axons running down from
brain
• Transverse (commissural) tracts– cross from 1 side
of cord to the other
sensory axons running up to brain
Ascending tracts
motor axons running down from
brain
Descending tracts
cross from 1 side
of cord to the other
Transverse (commissural) tracts
SPINAL ROOTS
• Dorsal – contains sensory axons that run from sensory cell
bodies in dorsal (posterior) root ganglion to dorsal (posterior)
horns
• Ventral – contain motor axons exiting from ventral (anterior)
horn
• Ventral Root unites with Sensory nerve distal to dorsal
(posterior) root ganglion to form Spinal nerve which exit
through intervertebral foramen out to body
_____– contains sensory axons that run from sensory cell
bodies in dorsal (posterior) root ganglion to dorsal (posterior)
horns
Dorsal
contain motor axons exiting from ventral (anterior)
horn
Ventral
