Chapter 3 Flashcards
Everything in the nervous system is described in relation to ____?
The Nuraxis
The front end is called _____ and the tail end is called ______
Anterior; Posterior
Toward the beak_____; toward the tail_____
Rostral; Caudal
Top of the head ______; towards the ground ______
Dorsal;Ventral
Superior = _____; Inferior =_____
Above; Below
Lateral means towards the ____; L Medial towards the ______.
Side/Edge;Middle/Inwards
Structures on the same side of the body are called
Ipsilateral
Structures on the opposite sides of the body are called
Contralateral
To cut the nervous system tranverserly means to cut it into _____?
Cross-sections
When you cut the nervous system Parallel to the ground it
gives you _______ sections
Horizontal
When you cut the nervous system Perpendicular to the ground and parallel to the nuraxis is gives _____ sections
Sagittal
The ______ divides the brain into two halves
Midsaggital sections
The entire nervous system (CNS & PNS) is covered by tough connective protective sheath called ______?
meninges.
Mengies have three layers these are
1.
2.
3.
- Dura Matter
- Arachnoid Membrane
- Pia Matter
The outer layer of the Mengies is called ____? and its characteristics are ?
Dura Matter, very thick, tough, lexable
The middle layer of the Mengies is called _____ ? and its characteristics are ?
Arachnoid Membrane, Soft and Spongy
The most inner layer of the mengies is called _____? and its characteristics are ?
Pia Matter, closely attached to the brain and spinal cord
the smaller surface blood vessels of the brain and spinal cord are contained in this layer
The CNS is covered in all three layers of mengies but the PNS is only covered in _____ & _____?
Dura Mater, Pia Mater
The Space between Between the pia mater and the arachnoid membrane is called the _____? this space is filled with ______?
Subarachnoid space; Cerebrospinal Fluid
The outermost layer of grey matter of the cerebral hemisphere is called the ____?
Cerebral Cortex
The brain contains several hollow interconnected chambers called ______ which are filled with ______
Ventricles; CSF
The largest chambers in the brain are the ________? which are connected to the _________?
Lateral Ventricles; Third Ventricle
The brain is divided into two symmetrical halves and the _______ walls line this division
Third Ventricle
choroid plexus is important because?
It manifactures the CSF
CSF has a half life of three hours; what does this mean?
This is the time it takes for half of the ventricular system to replace half of the CFS with fresh fluid.
What is the approx. amount of CSF?
125ml
The Process for CFS Removal
CFS i produced by the choroid plexus of the lateral vesicles and then flows into the __________ where more CFS is then produced which then flows through the _______ to the fourth ventricle where more CFS is produced. CFS then leaves the fourth ventricle through small opening that connect with the subarachnoid space surrounding the brain and flows through around the ______ where it is reabsorbed into the blood supply through arachnoid granulations.
Third Ventricle; Cerebral Aqueduct; CNS
The Process for CFS Removal
CFS i produced by the _______ of the lateral vesicles and then flows into the third ventricle where more CFS is then produced which then flows through the cerebral aqueduct to the________ where more CFS is produced. CFS then leaves the fourth ventricle through small opening that connect with the subarachnoid space surrounding the brain and flows through around the central nervous system where it is _______ into the blood supply through arachnoid granulations.
Choroid Plexus; Fourth Ventricle; Reabsorbed
hydrocephalus means?
Water Head - buildup and enlargement of vesicles
When does the development of the human nervous system begin?
Around the 18th day after conception
21 Days after conception ridges begin to touch each other and fuse together forming ________?
Neural Tube
What happens by day 28 after conception?
The neural tube closes
By day 28 after conception the neural tube is closed, and its rostral end (front) has developed three interconnected chambers, these are ventricles, and the tissue surrounding them becomes the three major parts of the brain;
- Forebrain
- Midbrain
- Hindbrain
_____ line the inside of the neural tube and give rise to the cells of the ______
Stem Cels; CNS
There cerebral cotex develops from the inside out and is made up of ___ layers
6
The stem cells that give rise to the cells in the brain are known as _______ cells.
Progenitor
The CNS origionates from the _____ during developmentq
Neural Tube
The outermost layer of grey matter of the cerebral hemisphere is called the ?
Cerebral Cortex
A layer of cells that line the inside of the neural tube; contains progenitor cells that divide and give rise to cells of the CNS
Ventricular Zone
A layer of progenitor cells located just inside the ventricular zone; thicker in mammals with large brains
Sub ventricular Zone
The size of the VZ is increased because ?
New Progenitor cells are made and increase the size of the VZ.
Some continue to divide into more progenitor cells and establish the sub ventricular zone (SVZ) - this phase is referred to as the Symmetrical Division. - it is called this because each division of a progenitor cell produced two new progenitor cells increasing the size of the VZ & SVZ.
When Progenitor cells increase what happens?
Some divide, into more progenitor cells and establish the SVZ - this is symmetrical division.
What is symmetrical division?
When progenitor cells divide two new cells are produced
How is the SVZ created?
By symmetrical division of the Progenitor cells
What is Asymmetrical Division?
When progenitor cells form two different kinds of cells as they divide; another progenitor cell and a brain cell (radial glia)
7 Weeks after conception the Progenitor cells receive a message to stop symmetrical division and begin ______?
Asymmetrical Division
How long does the period of Asymmetrical divison last?
Around 3 months
In Asymmetrical division radial glia are made. The cell bodies of the radial glia extend outwards from the ________ and attach to _______ located at the outer surface of what becomes the cerebral cortex.
Ventricular Zone; Pia Matter
Neurogenesis occurs in the _____ and the _____
Hippocampus; Olfactory Bulb
The end of cortical development is because of _______?
Apoptosis
Apoptosis is?
When progenitor cells receive a chemical signal that causes them to die
When progenitor cells receive a chemical signal that causes them to die it is called
Apotosis
At the time of Apoposis, _______ are transformed into Astorcytes
Radial Glia
Neurogenesis is ?
Production of new neurons through the division of neural stem cells
The ultimate size of the brain is determined by the size of _______
The VZ
The subventricular zone of ____________ is much thicker than that of smooth brains, it can be divided into two parts -
1 ____? 2_____?
Convulted Brains; the inner SVZ and the outer SVZ
The surface area of the brain is increased because it is ________?
Convulted
Once neurons have migrated to their final location they _______________? grow dendrites which receive the terminal buttons from axons and of other neurons and grow axons of their own.
Forming connections with other nerons
The growth of axons is guided by ______ and physical factors
Chemical
Once growth of an axon ends and their target is reached they form ___________
- each of these branches finds a vacant place on the membrane of the appropriate type of postsynaptic cell, grows a __________ and establishes a __________connection.
Branches; Terminal Button, Synaptic
The hippocampus is primarily involved in ?
Learning
The Olfactory Bulb is primarily involved in
The sense of smell
The adult brain contains stem cells that can divide and produce _________?. Detection of newly produced cells is done by administering a small amount of a radioactive form of one of the nucleotide bases the cells use to produce DNS that is needed for neurogenesis.
Neurons;
Neurogenesis can be supressed by
depression and/or stress
Neurogenesis can be reinstated by __?
Drugs that reduce stress/depression
During the first phase of brain development, _____________ of the progenitor cells of the ventricular and sub-ventricular zones, which lines the neural tubes, increases in size.
Symmetrical Division
During the second phase of brain development, ___________ of these cells gives rise to neurons, which migrate up the fibers of radial glial cells to their final resting places. There, neurons develop dendrites and axons and establish synaptic connections with other neurons.
Asymetrical Division
When a gene is duplicated, one of the copies can continue to perform vital functions, leaving the other copy for __________ through mutations.
Experimentation
The outer part of the spinal cord consists of __________; axons conveying information up or down.
White Matter
The central grey matter contains ?
Cell Bodies
Two main functions of the spinal cord is to distribute motor fibres to the effector origins of the body (glands and muscles) and to _________________?
collect somatosensory information to be passed onto the brain.
The spinal cord has a degree of ______ from the brain because of _______ controlling various circuits.
Autonomy; Reflexes
The Spinal cord is protected by __________ - this is composed of 24 _____________
vertebral column; individual vertebrae
The spinal cord only fills around two-thirds of the vertebral column; the rest of the space is filled by a mass __________ composing the cauda equina (a bundle of spinal roots located caudal to the end of the spinal cord).
Spinal Roots
What is the Cauda Equina?
A bundle of spinal roots
A Fissure is
A major groove in the surface of the brain
A Sulcus is
A groove in the surface of the cerebral hemisphere, smaller than a fissure
A convolution of the cortex of the cerebral hemispheres, separated by sulci or fissures is call ____?
Gyrus
This is something used in surgery where local aesthetic is injected into the CSF contained within the sac of dura mater surrounding the cauda equina.
This blocks that conduction in the axons.
Caudal Block
Layers of mengies wrap the spinal cord with small bundles of fibre emerging from each side of the spinal cord, these groups of bundles fuse together and becomes the thirty one paired sets of ________and___________.
Dorsal Roots; Ventral Roots
Afferent Means
Incoming
Efferent means
Outgoing
The spinal root that contains the incoming (afferent) sensory fibres is the
Dorsal Roots
The spinal root that contains the outgoing (efferent) motor fibers
Ventral Roots
The brain and spinal cord communicate with the rest of the body via cranial nerves and spinal nerves - these nerves are part of the _______?
PNS
Development of the nervous system begins around the ____ day of conception
18th
There are ____ pairs of cranial nerves attached to the ventral surface of the brain
12
The largest of the cranial nerves, conveying efferent fibers of the parasympathetic division of the autonomic nervous system to organs of the thoracic and abdominal cavities is called the ?
Vagus Nerve
Somatosensory information (taste) is received via cranial nerves, from _______ neurons
Unipolar Neurons
What is involved in the somatic nervous system which is part of the PNS?
- Auditory,
- Vestibular and
- Visual information is received via the olfactory bulbs
What is the role of the Autonomic Nervous System?
Regulation of smooth muscle
ie. skin, blood vesicles, eyes, and walls of the gut, gallbladder, urinary tract, cardiac muscle and glands.
What are the two division of the Autonomic Nervous System?
- Sympathetic Divison
2. Parasympathetic Division
What is the role of the sympathetic division in the Autonomic nervous system of the PNS
Controls activities that occur during excitement or exertion
- expenditure of energy
Give an example of the excitement or exertion that occurs in the Sympathetic division of the Autonomic nervous system of the PNS
Increased Heart rate
What is the role of the parasympathetic divison of the Autonomic nervous system of the PNS
Activities that increase the bodys supply of stored energy.
What is an example of what the parasympathetic divison of the Autonomic nervous system of the PNS does?
controls activities that occur during relaxation, such as decreased heart rate and increased activity of the digestive system.
What does the The adrenal medulla do?
secretes epinephrine and norepinephrine is controlled by axons of the sympathetic nervous system
What controls the adrenal medulla located?
The Sympathetic Nervous System