CNS: The Brain and Spinal Cord Flashcards
What layer is the Dura Mater and what does it do?
The outermost layer and the strongest. It connects the periosteum of bones.
What are dural sinuses?
Spaces within the Dura mater
Is the arachnoid Mater vascular or avascular?
Avascular
What is avascular?
No blood flow
What is vascular?
Blood flow occurs
What layer is the arachnoid Mater?
The middle layer
What characteristics does the Pia Mater have?
It is thin and transparent
Is the Pia mater vascular or avascular
Vascular
What is the function of the Pia Mater
To adhere tightly to the brain and spinal cord surfaces
What is cerebrospinal fluid?
A clear colorless liquid that is mostly made of water
What is the function of cerebrospinal fluid?
Protect against chemical and physical injuries.
Carry oxygen, glucose, and chemicals from blood to neurons and neuroglia
Where is the subarachnoid space located?
Between the arachnoid Mater and Pia mater
Where does The cerebrospinal fluid circulate through?
The subarachnoid Mater
Where is cerebrospinal fluid formed?
In the ventricles of the brain
Where is CSF secreted from?
Ependymal cells
What do meninges do?
Protect the central nervous system
Mechanical protection is a….
Shock absorber
What does chemical protection do?
Maintain an optimal chemical environment with ions
What does circulation provide?
An exchange of nutrients and waste between blood and nervous tissue
What is white matter?
Bundles of myelinated and unmyelinated axons
What is gray matter?
It contains dendrites, unmyelinated axons, axon terminals, and neuroglia
What three things does the spinal cord consist of?
A bony vertebral column, Meninges, epidural space
Where is epidural space and what does it consist of?
It is between the Dura Mater and vertebral column. It consists of fat and connective tissue for protection
What are the two parts the spinal cord is divided into?
Anterior (ventral) median fissure
Posterior (dorsal) median sulcus
What is a fissure?
A groove, fold or slit
What is a sulcus?
A groove or depression between two parts
What is in the center of a gray matter in what does it contain?
The central canal and it contains CSF
What is gray matter divided into?
Horns
What three horns is gray matter divided into?
Posterior (dorsal) gray horn
Anterior (ventral) gray horn
Lateral gray horn
In the posterior gray horn, what do cell bodies and axons of interneurons do?
Send impulses to other parts of the spinal cord and brain
What is in the anterior gray horn?
Cell bodies and axons of somatic motor neurons (muscle contraction)
Where is the lateral Gray Horn only in?
The Thoracic and upper lumber spinal region
What is in the lateral gray horn?
Cell bodies of autonomic motor neurons that regulate cardiac, smooth muscle, and gland activities
What is the function of gray matter in the spinal cord?
Receive and integrate incoming and outgoing information
What is white matter organized into?
Anterior, lateral, and posterior columns
What does each column in white matter contain?
One or more tracts
What is a tract?
Bundles of axons carrying the same information to the same destination
What do sensory (ascending) tracts do?
Send the impulse towards the brain
What do motor (descending) tracts do?
Send the impulse down the spinal cord
What is the function of white matter in the spinal cord?
Transfer sensory impulses from receptors to the brain and send a motor impulses from the brain to effectors (muscles, glands)
What are roots?
2 bundles of axons
What do roots connect?
Each spinal nerve to the spinal cord
What do anterior or ventral roots contain and what do they do?
They contain axons of motor neurons and conduct impulses from CNS to effectors
What do posterior or dorsal roots contain in what do they do?
They contain sensory neurons and dorsal root ganglion and conduct impulses from sensory receptors to CNS
What is the dorsal root ganglion?
Cell bodies of sensory neurons
What are effectors?
Muscles and glands
What are spinal reflexes?
A fast, involuntary response to a stimulus
What is a spinal reflex and give an example
Integration in spinal cord gray matter
Ex: patellar reflex
What is a cranial reflex and give an example
Integration in the brain stem.
Ex: eye movement
Give an example of a somatic reflex
Muscle contraction
What is an autonomic (visceral) reflex?
Response to smooth muscle, heart, and glands
Name three characteristics of the brain
Contains 100 billion neurons
Name the four parts of the brain
Cerebrum, diencephalon, brain stem, and the cerebellum
What does the brain maintain homeostasis through?
Sensory inputs and motor outputs
What are the three functions of the brain?
Maintain homeostasis, make decisions, integrating store new information
Why are there folds in the brain and what are they called?
The brain grows more rapidly than the skull and it folds to occupy space. They are called convolutions
What are shallow grooves called?
Sulci (sulcus)
What are the deepest grooves called?
Fissures
What does the longitudinal fissure separate?
Cerebral hemispheres
What does the cerebrum provide us the ability to do?
Read, write, speak, analyze, memory
What is the largest part of the brain?
The cerebrum
How thick is the cerebral cortex?
2-4 millimeters thick
What are the two cerebral hemispheres connected by?
The corpus callosum
What is the corpus callosum?
A bandof white matter containing axons that extend between hemispheres
Name the four lobes of the cerebrum.
Frontal, Temporal, occipital, and parietal
What are the three functional areas of the cerebrum?
Sensory areas, motor areas, and association areas
What do sensory areas in the cerebrum do?
Receives sensory information and are involved in perception
What is the motor area involved in in the cerebrum?
Intimate involuntary movements
What are association areas involved in?
Memory, emotions, reasoning, judgment, personality traits, and intelligence
Where are the sensory areas located in the brain?
The posterior half of the cerebral hemispheres
What is the primary somatosensory area do?
Allows you to know the exact points on the body where sensations originate
• pressure, temperature, pain, joint and muscle position
What does the primary gustatory area deal with?
Taste
What does the primary olfactory area deal with?
Smell
What are outward fold or bumps called?
Gyri
