The Nervous System: Spinal Cord, Spinal Nerves Flashcards
What is the nervous system?
It’s the body’s control center & communication network
What are the two major categories of the nervous system?
Central nervous system (CNS)
Peripheral Nervous system (PNS)
What does the CNS control?
Control center for whole body. Includes the brain and spinal cord
What does the peripheral nervous system (PNS) made up of?
All the nerves that connect the brain and spinal cord with sensory receptors, muscle, and glands.
What are the two categories that the PNS is divided up into?
The Afferent peripheral system and the Efferent peripheral system
What does the Afferent peripheral system include?
Afferent (sensory neurons) that convey information from receptors in the periphery of the body to the brain Nd spinal cord
What does the efferent peripheral system do/consist of?
Consist of Efferent (motor) neurons and coveys information from the brain and spinal cord to muscles and glands
What are the two subdivisions that the efferent can be further divided into?
The Somatic nervous system
Autonomic nervous system
What does the somatic nervous system do?
It conducts impulses from the brain and spinal cord to skeletal muscle. Thereby causing us to respond/react to changes in our external environment.
What does the automotive nervous system do? (ANS)
It conducts impulses from the brain and spinal cord to smooth muscle tissue (digestive track), cardiac muscle tissue and endocrine glands. ANS is considered to be involuntary.
What are the two subdivisions of Autonomic nervous system (ANS)?
The sympathetic and parasymethic division
What does the sympathetic do, and what neurotransmitter does it use?
The Sympatheic stimulates or speeds up activity and energy expenditure in fight or flight responses.
Uses Norepinephrine
What does the parasympatheic divison do?
Stimulates/speeds up body’s vegetative activities such as digestion, urination and restores, slows down other activities.
It uses acetylcholine as its neurotransmitter
What are neurons?
Nerve cells
What do neurons do?
transmit nerve impulses electrochemically.
What is a nerve?
A bundle of nerve cells or fibres.
What is a neuroglia?
Cells that perform support and protection
Neuroglia are also called what?
Glial cells.
They make up over 60% of all brain cells
Do neuroglia cells conduct impulses?
NO
What are the different types of Neruoglia? (5)
Astrocytes: star shaped cells that wrap round nerve cells for supporting network in the brain and spinal cord.
Oligodendroglia: (look like small astrocytes) forming semirigid connective-like tissue rows between neurons in the brain and spinal cord.
(Also produce Myelin)
Microglia: small cells that protect the CNS and whose role is to engulf and destroy microbes like bacteria and cellar debris
Ependymal cells: line the fluid-filled ventricles of the brain. Produce cerebrospinal fluid, other move the fluid with cilia through the CNS
Schwann cells from myelin sheaths around nerve fibers in the PNS
What is a percept?
The brain’s record of event. Can be conscious or unconscious
What are the myelin sheaths used for?
Protection and insulation/
Are Schwann cells located in both the CNS and PNS?
No they are only located in the PNS
What do the Ependymal cells line?
The cavities of the brain and spinal cord
What do Oligodendroglia do?
They provide support and connection
What do microglia do?
Phagocytosis of unwanted substances
What do astrocytes do?
(Star shaped) function in the blood-brain barrier to prevent toxic substances from entering the brain
What are dendrites?
Dendrites are short/branched like. These are the receptive areas of the neurons and a multipolar neruron will have many dendrites.
What is an axon?
It begins at the cell body (slightly enlarged = axon hillock) branches down into axon terminals.
What are located in the axon?
Mitochondria and neurofibrils
What cell produces the fatty myelin sheath on peripheral axons?
Schwann cells
What is the myelin sheath composed of?
Lipoproteins
What are the narrow gaps between the myelin sheath called?
Nodes of Ranvier
How are neurons classified?
Shape and structure
How would you describe a multipolar neuron?
Have several dendrites and one axon.
Found in brain and spinal cord
What is another name for a Schwann cell?
Neurolemmocyte
What does the Schwann cell/neurolemmocyte do?
It surrounds the axon at specific sites and forms the fatty myelin sheath around the axons in PNS
What is another name for a node of Ranvier?
nerurofibril nodes.
What is the purpose of the Node of Ranvier/nerurofibril node?
The gap allows ions to flow freely from extracelluar fluids to the axons, assisting in developing action potentials for nerve transmission.
What produces myelin sheaths in the CNS
Obligodendrocyte
How would you describe a bipolar neuron?
Have one dendrite and one axon.
Function as receptors cells in special sense organs. Found in retina of eye, inner ear, olfactory area of the nose
What is a unipolar neuron?
Only have one process extending from the cell body. This single process then branches into a central branch that functions s an axon Nd a peripheral branch that functions as a dendrites. Most are this type
What is the first nerve cell receiving an impulse directly from a receptor called?
Sensory/afferent neuron
What type of neuron is found t the sensory/afferent neuron?
Unipolar
Why is a sensory/afferent neuron unipolar?
The receptors are in contact with only one end of the sensory neuron to ensure one-way transmission of the impulse
What type of neuron is a motor/efferent neuron
Typically multipolar. This bring about the action to the original stimulus
What ions are inside/outside the neruon?
Na ions are outside the cell and K are inside
What is depolarization?
The reversal of electrical charge from resting potential
How is the action potential created
By the depolarization of the nerve, the action potential moves in one direction down the nerve fibre
What is repolarization?
K ions move out side to restore the resting membrane potential. The Na-K pumps begins to function and pumps the K in and Na outside restoring the original charge
What is Synapses?
Areas where the terminal branches of an axon (axon terminals) are anchored close to the end of the dendrite of another neuron
what is the area between the axon terminals and dendrites called?
Synaptic cleft
What eats up acetylcholine in the synapse?
Acetylcholinesterase. It functions immediately to break down acteylcholine after it performs its function.
What neurotransmitter are found in the nervous system?
ANS: adrenaline (epinephrine)
Acetylincholine, norepinephrine, serotonin, dopamine, endorphins
What is the reflex?
A reflex is an involuntary reaction to a stimulus applied to our periphery and transmitted to the CNS
What is a reflex arc?
1) sensory receptor in skin
2) sensory/afferent neuron
3) associated internuncial neruon within the spinal cord
4) a motor or efferent neuron
5) an effector organ (muscles)
What are examples of reflexes?
Heartbeat rate, digestion, breathing,coughing, sneezing, swallowing, vomiting
What is white matter?
Group of myelinated axons = nerver tracts in the CNS
What is grey matter?
Nerve bodies and dendrites , unmyelinated axons and their neuroglia.
Found on the surface of the brain called the cortex
What is a tract?
A bundle of fibres inside the CNS.
What is a nucleus?
A mass of nerve cell bodies and dendrites inside the CNS
What are horns?
Ares of grey matter in the spinal cord
What is a receptor?
Detect environmental stilumli
What is a sensory?
Recieves impulses from receptors site
What is internuncical?
Transmit impulse for interpretation and processing
Motor?
Rxn to the stimulus
What does acetylcholine do?
Opens up Na channels
What is Serotonin responsible for?
Happyness and well-being
What do Endorphins do?
Exercise= natural pain killer, makes you feel good
What does Glutamine do?
its excitatory, amino acid, increases electrical activity
What does GABA do
It’s an inhibitory, makes it less negative. Inhibits transmission of an impulse.
Used to treat epilepsy and hypertension.
Slows things down
What group of neurotransmitters is made of up the amino acids Tyrosine. What do they do?
Catecholamines . They are created during physical/emotional stress. Found in the SNS system
Nitric oxide does what?
Dilates blood vessels, raising blood supply and lowering blood pressure. It inhibits vascular smooth muscle contraction and growth
What is a nerve:
Bundle of fibers outside the CNS
What is a ganglia?
Nerve cell bodies outside the CNS
What is a tract:
Bundle of fibres inside the CNS
What is a nucleus?
nerve cell bodies and dendrites inside the CNS
What are horns?
Areas of gray matter in spinal cord
What is a continuation of the medulla oblongata of the brain stem?
The spinal cord
What protects the spinal cord?
Bone (vertebrae) and disk of fibrocartilage (the intervertebral disk)
How many segments does the spinal cord have
31
What are the three layers of the Mengies (a serious of connective tissue membrane):
1) Dura mater: outter most, means tough, forms outer tube of white fibrous connective tissue
2) Arachnoid mater: middle spinal meninx (spider layer), delicate connective membranous tube inside the dura
3) Pia mater: innermost layer, delicate mother, transparent fibrous membrane forms. Tube around and adhere’s to the surface of the spinal cord and brain. The pia mater contains blood vessels and nerves that nourish the underlying cells
What is in between the Dura mater and the arachnoid?
It’s a space called Subdural containing serous fluid.
What is between the arachnoid and pia mater?
It’s the subarachnoid space. Clear, watery cerebrospinal fluid circulates
Do the meninges directly attach to the vertebrae?
No, they are separated by a space called the epidural space.
What does the epidural space contain?
Contains loose connective tissue and some adipose tissue that acts as a protective cushion around the spinal cord.
What does an epidermal do?
Regional pain relief. Blocks nerve impulses from the lower half of the body
What is the function of the spinal cord?
Convey sensory impulses to the brain,
Integrates reflexes, spinal nerves connect at roots (dorsal, ventral)
What does dorsal root do in the spinal cord?
Sensory
What does ventral root do?
Motor
What do ascending nerve tracts do?
From body part to brain (sensory)
What do descending tracts do?
Conduct motor impulses from the brain to muscles glands.
What do posterior/dorsal roots do?
They conduct the sensory root and only contains sensory nerve fibres.
What do posterior/dorsal roots extend to?
Into the posterior or dorsal gray horn of the spinal corn.
What do the Anterior/ventral root do?
It’s a point of attachment to the spinal nerve. Contains motor roots/fibres and only conducts impulses from the spinal cord to the periphery. It contains anterior or ventral gray horns of the spinal cord.
What do the 31 spinal nerves arise from
The union of dorsal and ventral roots
What is a nerve?
Bundle of nerve cells
What is a nerve?
A bundle of fibres outside the CNS
What are ganglia?
Nerve cell bodies found outside the CNS
How my pairs cervical nerves are there?
8 (C1-C8)
how many pairs of thoracic nerves are there?
12 (T1-T12)
How many pairs of lumbar nerves are there?
5 (1-L5)
How many pairs of sacral nerves are there?
5 (S1-S5)
How many pairs of coccygeal nerves are there?
1 (Cx)
The nervous system shares in the maintenance of homeostasis with which system?
Endocrine
The system that conducts impulses from the brain and spinal cord to skeletal muscles is the?
Somatic
The ‘glue’ cells that perform the function of support and protect are:
Neuroglia
Oligodendroglia are found in
Brain and spinal cord
Phagocytosis is performed by:
Microglia
The cells that make up myelin sheaths are
Schwann cells
The cells that line the cavities in the brain and spinal cord are
Ependymal cells
Nissl bodies are attached to
The ER. Nissl bodies are also called chromtophilic substance. Nd are where protein synthesis occurs in nerurons
Neurommocytes are also known as
Schwann cells
A neuron with one axon and one dendrite is known as
Bipolar: special sense organs such as the retina of eye have these
Receptors are
Afferent neurons
Rxn neurons are
Efferent neurons
The sodium pump is used to maintain the
Membrane = resting potential
The smallest simplest pathway to receive and process a stimulus is the
Reflex
Some of the most commonly abused drugs are:
Steroids,
Depressants,
Stimulants,
Hallucinogens
Ganglia are found
Out side the brain and spinal cord
Gray matter is found in the
Cortex->consists of dendrites and cell bodies and bundles of unmyelinated axons and their neuroglia
The tough mother is the
Dura mother
The layer of the meninges containing numerous blood vessels and nerves is the
Pia layer
The spider layer is the
Arachnoid layer
Serous fluid is found in the
Subdural. In between the dura and the arachnoid mengies
Spinal taps are done in which region of the spine?
The lumbar
Meninges are separated from the vertebrae by the
Epidural space. This contains loose connective tissue and some adipose tissues that acts s a protective cushion around the spinal cord
The functions of the spinal cord include:
Reflex & conveyance (of impulse)
The enzyme that breaks down acetylcholine is
Acetylcholinesterase
Heart rate, digestion, breathing rates are controlled and maintained by reflexes concerned with _________ processes
Involuntary
How many of spinal nerves are there
31
The disease that produces convulsive seizure is?
Epilepsy
The disease that produces infection in the middle ear is?
Otitis media
The disease that produces defective muscular coordination
Cerebral palsy
Farsightedness is?
Hyperopia
An accommodation disease of aging is?
Presbyopia
A disease that causes destruction of the retina is?
Glaucoma
Nearsightedness is?
Myopia
The part of the ear allowing for pressure equlization is the
Eustachian tube
The part of the ear allowing for balance is the
Vestibule & semicircular canals
The part of the ear citing like a drum head is the
Tympanic membrane
Night blindness can be caused by deficiency of
Vitamin A
The ability to see colour is due to
Cones
The white, outermost layer of the eye is the
Sclera
The cells of the retina that synapse with ganglia cells are
Bipolar
Glaucoma is caused by a defect of the
Aqueous humour
Glaucoma is caused by a defect of the
Aqueous humour
Rhodopsin is found in the
Rods
The actual taste function is found on the
Taste hairs
The actual taste function is found on the
Taste hair
Chemoreceptors are used in the sense of
Smell
The cardinal nerves number
12
The neurotransmitter associated with the parasympathetic system is
Acetylcholine
List the functions of the cerebellum
- reflex
- posture
- coordination
- balance
Which lobe of the cerebrum evaluates hearing input
The temporal lobe
Which lobe of the cerebrum is involved with visual input?
Occipital
Which lobe of the cerebrum is involved in evaluating sensory information?
Parietal
Which lobe of the cerebrum controls mood, aggression and motivation?
Frontal
Each hemisphere has folds called
Gyri
The mind controlling the body phenomenon is located in the
Hypothalamus
The ventral cerebral peduncles are continued in the
Midbrain
The foramen of Monroe connects
Ventricles
What is the outermost layer of the cranial meninges?
Dura mater-tough mother
The part of the epithalamus that secrets melantonin is the
Pineal gland
The coloured part of the eye that consists of smooth muscle surround the pupil is the
Iris
