Structure of the Nervous System Flashcards
What is the nervous system made of?
Neurons and glia (nervous tissue)
what do neurons do?
Communicate with other neurons
What does glia do?
Support neural function and clears out debris, toxins and bacteria from the brain
What is the central nervous system composed of?
Brain and spinal cord
What is the peripheral nervous system composed of?
Nerves
What are the 2 divisions of the peripheral nervous system?
Somatic (SNS) and Autonomic (ANS)
What are the 2 divisions of the autonomic nervous system?
Sympathetic and parasympathetic
What does the sympathetic nervous system do?
fight/flight response
What does the parasympathetic nervous system do?
Feed or breed (rest or digest)
digestion, calm, formation of sex cells, etc
What is the name of the 1st phase of the development of the CNS?
Gastrulation
What happens 5 days after fertilization of an ocyte by a sperm?
A blastocyst (fluid-filled ball) begins to form
What is into a blastocyst?
The embryonic disk: mass of cells that develop within the blastocyst and will become an organism
What does the blastocyst transform into? What is this process called?
The gastrula, through gastrulation
What are the 3 layers of cells composing the gastrula?
Ectoderm
Mesoderm
Endoderm
What will the ectoderm form eventually?
Nervous system and skin
What will the mesoderm form eventually?
muscles, skeleton and internal organs, circulatory system
What will the endoderm form eventually?
digestive system, lungs and glands
What is neurulation?
developmental process by which the neural tube is formed
What is the step after gastrulation?
the edges of the ectoderm raise and become neural folds, this results in a central depression called neural groove
What is the notochord?
will serve of skeleton to the embryo until the vertebrae forms (made of cells from the mesoderm)
What part of the gastrula will become the spinal cord?
The neural plate (neural folds+neural groove)
What will happen to the neural folds?
They will move towards each other and fuse, forming the neural tube
What is the neural crest made of
Cells from the ectoderm migrating to both sides of the neural tube
What role does the mesoderm play in neurulation?
It forms protusions (somites) on either side of the neural tube, which will make the vertebras
When does the neural tube expands to become the primary brain vesicles?
25 days after conception
What part of the neural tube will form the primary brain vesicles?
The rostral end
What are the 3 primary brain vesicles?
Forebrain
Midbrain
Hindbrain
After how much time will the primary brain vesicles become secondary brain vesicles?
40 days after conception
What secondary brain vesicles are associated with the forebrain?
Telencephalon and Diencephalon
What secondary brain vesicle are associated with the midbrain?
Mesencephalon
What secondary brain vesicle are associated with the hindbrain?
Metencephalon and myelencephalon
What parts of the brain will the telencephalon become?
the brain hemispheres (cortex), the basal ganglia, the olfactory bulb, the hippocampus and the amygdala
What parts of the brain will the diencephalon become?
The thalamus and hypothalamus
What parts of the brain will the mesencephalon become?
The tectum (superior colliculus and inferior colliculus), and the tegmentum (periaqueductal gray matter, substantia nigra and red nucleus)
What parts of the brain will the metencephalon become?
The cerebellum and the pons
What parts of the brain will the myelencephalon become?
The medulla
What are the roles of the circumvolutions on the surface of the brain?
- Can augment the surface area of the cortex
- Have roles in enhancing connectivity between neurons
- Serve as anatomical landmarks useful for designating specific brain areas (ex: interhemispheric fissure)
What important structures are in the frontal lobes?
Broca’s area (left lobe), precentral gyrus (primary motor cortex)
What important structures are in the parietal lobes?
The primary somatosensory cortex (postcentral gyrus), the posterior parietal cortex, and the medial parietal region
What important structures are in the temporal lobes?
Wernicke’s area, and primary auditory cortex
What important structures are in the occipital lobes?
Primary visual cortex
What is the Broca’s area responsible for?
speech production
What is the precentral gyrus (primary motor cortex) responsible for?
body movement
What is the primary somatosensory cortex (postcentral gyrus) responsible for?
Sensation in parts of the body
What is the posterior parietal cortex responsible for?
Proprioception (ability to sense the position of the body)
What is the medial parietal region responsible for?
“route knowledge”
What is the Wernicke’s area responsible for?
understanding language
What is the primary auditory cortex responsible for?
analyze of sounds
What is the primary visual cortex responsible for?
Where visual information is 1st analyzed
What are the 3 subcortical structures
The basal ganglia, the hippocampus and the amygdala
What is the basal ganglia composed of (3 nuclei)
- Ventral striatum (nucleus acumbens)
- Dorsal Striatum (caudate nucleus and putamen)
- Substantia Nigra
What is the basal ganglia responsible for?
smooth exectution of movements and selection of appropriate actions
What is the hippocampus responsible for?
Plays a role in memory and in spatial environment navigation
What is the amygdala responsible for?
processing emotions and fear
What are the 2 structures of the forebrain?
Diencephalon and Telencephalon
What is the role of the thalamus?
rely station between sensory receptors and interpreting brain regions (except for smells)
What is the hypothalamus responsible for?
major player in body homeostasis and in the release of hormones
What is the midbrain responsible for?
Motor movements, auditory and visual processing
What is the midbrain (mesencephalon) composed of?
The tectum (superior and inferior colliculus) and tegmentum
What is the hindbrain composed of?
The pons, the medulla and the cerebellum
How is the spinal cord divided in terms of spinal nerves?
- 8 cervical (8 spinal nerves)
- 12 thoracic (12 spinal nerves)
- 5 lumbar (5 spinal nerves)
- 5 sacral (5 spinal nerves)
- 3 coccygeal (1 spinal nerve)
How many spinal nerves are there considering we have 33 vertebras? why?
31 spinal nerves; the 2 last coccygeal vertebrae do not have a corresponding spinal nerve
What is the grey matter in the spinal cord made of?
cell bodies of neurons (ventral and dorsal roots are made of this)
What is the white matter in the spinal cord made of?
axons of the neurons (carry info from and to the brain)
Where do sensory nerve fibers enter the spinal cord through?
The dorsal nerve root (made of ascending fibers)
Where do motor nerve fibers exit the spinal cord through?
Ventral nerve roots (descending fibers)
What are the 2 parts of the peripheral nervous system?
Somatic NS (brain and major muscles/sensory systems) and Autonomic NS (brain and viscera; sympathetic and parasympathetic NS)
What are the 3 layers of protection of the brain?
- Meninges
- Cerebrospinal fluid
- Blood-brain barrier
What are the 3 parts of the meninges?
Pia mater
Arachnoid
Dura mater
