Organization of the Nervous System l Flashcards
What is the Brain Theory? (2)
-The brain is the source of all behavior
-Brain abnormalities often underlie communication disorders
What is the Neuron Theory?
The unit of brain structure and function is the neuron
The brain is composed of two ___________.
Two symmetrical hemispheres, the right hemisphere and the left hemisphere
The hemispheres are connected by?
By commissures and the largest is the Corpus Callosum
The inner hollow tube of the brain is filled by?
Cerebrospinal Fluid (CSF)
What is the cerebral cortex?
It’s the outer layer of the brain (bark). It is wrinkled tissue.
What is are Gyri?
They are the folds of the Cerebral Cortex.
What are Sulci?
Creases between the folds.
What are Fissures?
Large sulci e.g. Longitudinal and Lateral fissure.
The brain is divided into how many lobes and what are their names?
Divided into four lobes
Frontal Lobe
Parietal Lobe
Occipital Lobe
Temporal Lobe
True or False: Each hemisphere has a lobe?
True: (e.g., right frontal lobe & left frontal lobe)
What are the three divisions of the Central Nervous System (CNS)?
Forebrain, Brainstem, Spinal Cord.
Describe the Forebrain + Function. (2)
- Cerebral cortex & subcortical structures
- Performs higher functions like speaking, thinking, planning, remembering and perception
Describe the Brainstem + Function. (2)
- It is the underlying tube
- It performs regulatory and movement producing functions
Describe the Spinal Cord + general Function. (2)
- It is connected to brainstem and descends down the back
- It performs regulatory and movement producing functions
What constitutes the CNS and describe it’s regeneration after damage.
The brain and the spinal cord
Tissue does not regenerate after damage
What constitutes the PNS and describe it’s regeneration after damage.
Fibers in the periphery that carry information to and from the CNS
Tissue can regenerate after damage
The PNS is divided into the _____________ and __________.
Somatic Nervous System (SNS) and the Autonomic Nervous System (ANS).
What are the functions of the SNS? (Sensory and motor pathways)
- Sensory Pathways: Collect information from the senses and send it to the cortex
- Motor Pathways: Nerve fibers that connect the brain and spinal cord to the body’s muscles
What are the functions of the ANS?
Sensory & motor pathways that control the internal organs such as the heart, lungs, and stomach. (Sympathetic and Para-sympathetic NS)
What does Localization mean?
Different parts of the brain have different functions.
What does Lateralization mean?
Functions are localized on one side of the brain. E.g. Language processing and production.
Where is Broca’s area?
Inferior frontal gyrus, below the inferior convolution.
What is Broca’s aphasia?
Syndrome that results from damage to Broca’s Area (motor speech area). Unable to produce speech.
According to the neuron theory, what are characteristics of Neurons? (3)
- Neurons are discrete
- Neurons carry an electrical signal
- Neurons communicate with each other via a chemical signal, or a neurotransmitter
What are the three major parts of neurons?
Dendrites, Cell body (soma), Axon
What are the roles of Glia cells ? (2)
Hold Neurons together and carry out supportive functions
Neurons ______ information, _________information, and ___on information
Acquire information, process information, and act on information
What are Synapses?
Junctions between neurons.
What makes neurons discrete?
The fact that they never touch.
The Hebb rules states that…
When cells are activated at the same time they establish or strengthen the synapse.
What is neuroplasticity?
The brain’s ability to modify, change, and adapt both structure and function in response to experience.
Frequently used Anatomical Term
Rostral / _______
Anterior /_______
_______ / Ventral
_______ / Inferior
Lateral / ______
Rostral / Caudal
Anterior / Posterior
Dorsal / Ventral
Superior / Inferior
Lateral / Medial
3 Frequently Used Brain Sections in medical pictures.
Coronal
Horizontal
Sagittal
Structures on the same side are ____________.
Structures on the same side are Ipsilateral
Structures on the opposite side are __________.
Structures on the opposite side are Contralateral
Structures that lie in both hemispheres are ________.
Structures that lie in both hemispheres are Bilateral
Pathways that go away from brain structures are ___________. E.g.____________.
Efferent.
E.g.: Motor Pathway
Pathways that go toward brain structures are ___________
E.g. ______________
Afferent
E.g. Sensory Pathway
Support and Protection characteristics of the CNS. (3)
- Brain enclosed in the skull
-Spinal cord encased in bony vertebrae - Meninges
- CSF
- BBB
What are the Meninges?
Three layers of membranes inside the skull and vertebrae.
What are the 3 layers of the meninges?
- Dura Mater
- Arachnoid Membrane
- Pia Mater
What are the roles of the CSF?
Cushions the brain and Spinal cord (CNS) and removes waste.
What are the roles of the Blood-brain-barrier? (3)
- Shields the brain from toxic substances in the blood
- Supplies brain tissues with nutrients,
- Filters harmful compounds from the brain back to the bloodstream.
What arteries supply the brain ? (2)
Two internal carotid arteries
Two vertebral arteries
Connect at the base of the brain and branch off into the:
________Cerebral Artery
________Cerebral Artery
________Cerebral Artery
Connect at the base of the brain and branch off into the:
Anterior Cerebral Artery
Middle Cerebral Artery
Posterior Cerebral Artery
What causes a stroke?
Interruption of blood flow to the brain that kills brain cells
What are the two types of stroke?
- Ischemia - deficiency of blood flow to the brain
- Hemorrhagic stroke – burst of a blood vessel
Characteristics of Neural Stem Cells:
- Undifferentiated
- Capacity for self-renewal
Characteristics of Progenitor Cells (2):
- Develop from stem cells
- Give rise to blasts, primitive types of nervous system cells
Neuroblasts develop into _______ or _____.
Develop into neurons or glia.
What are the types of glial cells? (5)
- Ependymal (produce CSF)
- Astrocyte (nutritive and Support function)
- Microglial (Defensive Function)
- Oligodendroglial (Myelin for CNS)
- Schwann (Myelin for PNS)
Gray Matter consists of_____.
Color from capillary blood vessels and neuronal cell bodies.
White matter consists of________.
Color from axons covered in an insulating layer of glial cells.
What are nerves?
Fibers and fiber pathways within the PNS that enter and leave the CNS. E.g. Auditory nerve.
What is a tract?
Large collection of axons projecting to or away from a layer or nucleus within the CNS
Examples: Corticospinal Tract, Optic Tract
What are Layers/Nuclei?
Large well-defined cluster of neurons deep inside the hemispheres and brainstem.
What are ventricles?
4 large open structures which lie deep inside your brain filled with CSF.
Paul Broca had a patient Had patient who was only able to say “tan” with paralysis on the right side of the body
Where would the patient have a lesion on his brain?
To the third convolution of the left frontal lobe was found
What are the three convolutions?
- Superior
- Middle
- Inferior
Structures that are close together are?
Proximal
Structures that are far apart are?
Distal
True or false: An MCA stroke can cause changes in behavior and personality?
True
The third and fourth ventricles extend into the __________ and the _________
Brainstem and spinal cord
Describe the Ventricles (2).
- Hollow pockets within the brain filled with CSF
- Choroid plexus (glial cell structure) produces CSF
