Chapter 11 - Nervous System continued Flashcards
Central nervous system (CNS):
- Consists of brain and spinal cord.
- Brain is largest and most complex portion of nervous
system - Brain controls sensation, perception, movement, thinking
- Brain consists of 2 cerebral hemispheres, diencephalon,
brainstem, cerebellum - Brainstem connects the brain to the spinal cord
- Both brain and spinal cord connect to the peripheral
nervous system (PNS) by way of peripheral nerves - Meninges
Meninges
membranes that protect brain and spinal cord;
lie between bone and soft tissues of nervous system
The meninges:
* Membranes that protect brain and spinal cord
* Consist of 3 layers which are…?
Dura Mater
Arachnoid Mater
Pia Mater
Dura Mater
- Outer layer
- Tough, dense connective tissue
- Dural sinuses
- Epidural space
Arachnoid mater:
- Middle layer; web-like
- Subarachnoid space contains cerebrospinal fluid (CSF)
Pia Mater
- Inner layer; attached to surface of brain, spinal cord
- Contains blood vessels and nerves
- Nourishes CNS
CSF is produced in 4…
ventricles, interconnected cavities
within cerebral hemispheres, and brainstem
-Ventricles are continuous with the central canal of the spinal
cord
what are the 4 Ventricles
- 2 Lateral ventricles (called the first and second ventricles)
- Third ventricle
- Fourth ventricle
Interventricular foramina
connect third to lateral ventricles
Cerebral aqueduct
connects third and fourth ventricles
Cerebrospinal Fluid
- Secreted by the choroid plexuses, special capillaries of
pia mater covered by ependymal cells - Selective transfer of substances from the blood to form
CSF - Nutritive and protective of CNS neurons
- Helps maintain stable ionic concentrations in the CNS
- Circulates in ventricles, central canal of spinal cord, and
subarachnoid space - After exchanging substances, CSF is absorbed by the
arachnoid granulations - Volume is about 140 mL at any time
The brain contains centers for/performs the following
functions…?
- Neural centers for sensory function
- Sensations and perceptions
- Motor commands to skeletal muscles
- Higher mental functions, such as memory, reasoning
- Neural centers for coordinating muscular movement
- Neural centers for regulating visceral activities
- Personality
Neural tube gives rise to…?
CNS
Brain forms from 3 Vesicles (cavaties)
- Forebrain (prosencephalon)
- Midbrain (mesencephalon)
- Hindbrain (rhombencephalon)
3 vesicles facts
-Forebrain divides into the telencephalon and diencephalon
-Mesencephalon persists
-Hindbrain divides into metencephalon and myelencephalon
-These 5 cavities persist in mature brain as ventricles and tubes that
connect them:
* Forebrain becomes cerebrum, basal nuclei, and diencephalon
* Mesencephalon remains as midbrain
* Hindbrain becomes cerebellum, pons, and medulla oblongata
10
what are the Major portions of the adult brain
- Cerebrum
- Diencephalon
- Cerebellum
- Brainstem
Cerebrum is the _______ part of the brain
Largest
Structures of the Cerebrum
Cerebral hemispheres: 2 halves, separated by falx
cerebri
* Corpus callosum: Connects cerebral hemispheres
* Gyri: Ridges or convolutions
* Sulci: Shallow grooves in surface; example: Central
sulcus
* Fissures:
* Deep grooves in surface
* Longitudinal: separates the cerebral hemispheres
* Transverse: separates cerebrum from cerebellum
What are the 5 lobes of the cerebral of hemispheres?
- Frontal lobe
- Parietal lobe
- Temporal lobe
- Occipital lobe
- Insula (Island of Reil): Deep within lateral sulcus
4 of the lobes are named for the bones that they underlie
Cerebral Cortex:
- Thin layer of gray matter, which
makes up outermost layer of all outer
lobes of the cerebrum - Contains almost 75% of neuron cell
bodies in nervous system
White Matter of Cerebrum:
- Lies under cerebral cortex
- Makes up most of cerebrum
- Contains bundles of myelinated axons
that connect neuron cell bodies in
cerebral cortex to other portions of
nervous system
What is the Cerebral Cortex responsible for?
Higher Mental Functions
What are the functions of the Cerebral Cortex?
- Interpreting impulses from sensory organs
- Initiating voluntary movements
- Storing information as memory
- Retrieving stored information
- Reasoning
- Seat of intelligence and personality
-The cerebral cortex can be divided into sensory, association
and motor areas; some overlap exists
-Each area contains a group of neurons working together to
perform a particular function
Cutaneous sensory area: (sensory)
- Parietal lobe
- Interprets sensations on skin
Sensory speech area (Wernicke’s area): (sensory)
- Temporal/parietal lobe, usually left hemisphere
- Understanding and formulating language
Visual area: (sensory)
Occipital lobe
* Interprets vision
Auditory area: (sensory)
- Temporal lobe
- Interprets hearing
Sensory area for taste: (sensory)
- Near base of the central sulcus
- Includes part of insula
Sensory area for smell: (sensory)
Arises from centers deep within temporal lobes
Frontal lobe association areas: (assosiation area of the cortex)
- Concentrating, planning, complex problem solving
- Emotional behavior, judging consequences of behavior
Parietal lobe association areas: Association Areas of the Cortex
- Understanding speech
- Choosing words to express thoughts and feelings
Temporal lobe association areas: Association Areas of the Cortex
- Interpret complex sensory experiences (understanding speech,
reading) - Store memories of visual scenes, music, and complex patterns
Occipital lobe association areas: Association Areas of the Cortex
Analyze and combine visual images with other sensory experiences
Insula: Association Areas of the Cortex
Translating sensory information into proper emotional responses