Nervous system Flashcards
Nervous system and endocrine system difference
Nervous system is faster to respond, action lasts for a shorter time, has a specific target and neurotransmitters are invovled (hormones involved in endocrine system)
Functions of t he nervous system
- monitors body’s internal and external environments
- Integrates sensory information
-Co-oridnates volutary and involuntary responses of all other organ system
What are the 2 parts of the nervous systems in the body
Centeral nervous system (CNS) and the peripheral nervous system (PNS)
What is the CNS made of and what is its function
Made up of brain and spinal cord
Function is to integrate and coordinate input and output
What is the PNS made of and what is its function
Made up of all the neural tissue outside of the CNS
Function: the connection between the CNS and the organs
What are the two divisions in the PNS and what does each do
Afferent division, brings sensory information to CNS from receptors of PNS
Efferent division, carries motor commands from CNS to effectors in organs and tissues
Identify the two functional divisions of the peripheral nervous system and describe their primary functions
Somatic Nervous system, controls skeletal muscle conractions
Autonomic nervous system, automatically regulates involuntary muscles (smooth, cardiac muscles n glandular secretions)
Consits of sympathetic and parasympathetic division
Name the two types of cell in the nervous tissue and describe thier primary function
Neurons, transmits nerve impulse
Neuroglia, protects support and regulate the environment around the neurons
State the structures of the neurons and its respective function
Dendrites, receive signals
cell body, contains the nuclues and organelles
axon hillock, where electrical signal begins
axon, carry signals to the next cell
axon terminals, bulb- shaped endings that form a stnapse with the next cell
What is a myelin sheath
A lipid covering on long axons that acts to increase the speed of nerve impulse conduction
What are the gaps between the myelination on axons called
Nodes of Ranvier
What are the structural classificiation of neurons and what type of information does it relay
Multipolar neurons, motor neurons in skeletal muscles
Unipolar neuron, sensory
Bipolar neuron, relay information about special sense- sight, smell, hearing, taste
What are the functional classification of neurons
Sensory (afferent) neurons: carry information from receptor to CNS
Motor (efferent) neurons: carry commands from Brain/ spinal cord to the effectors
Interneurons/ association neurons: connect sensory and motor neurons and is only found in CNS organs, involved in memory, planning and learning
Type of neuroglial cells in the CNS and their primary function (MOEA)
Microglia: Phagocytic cell
Oligodendrocytes: produce mylein that serve as electrical insulation to increase speed of signal transmission, white matter of CNS
Ependymal cell: Lines cavities in CNS and produces CSF
Astrocytes: maintain blood brain barrier
Type of cells in PNS and its primary function
Satelllite cells, support function
Schwann cells, produce mylein sheath that covers nerves in PNS
What causes a nerve impulse
change in the plasma membrane’s electrical potential may result in an action potential
What are the three types of potential
Resting membrane potential, -70mV
Graded potential, temporary localized change in resting potential caused by stimulus
Action potential, electrical impulse produced by a threshold stimuls that propagates along surface of axon to synapse
How is action potential generated
Resting membrane potential (70mV)
Depolarization, when sodium channel opens and sodium ions move into the cell
At +20mV,
Repolarization, where sodium channel closes n potassium channel opens, resulting in potassium ions moving out of the cell into the intracellular fluid
Hyperpolarization for a breif periodm -90mV
Return to resting membrane potential (the Na+ and K+ pump, 3 Na+ out 2 K+ in)
What are the two types of propagation and give a breif description of them respectively
Continous propagation, occus in unmyelinated fibers and is relatively slow
Saltatory propgation, is in myelinated axons and is faster
(your high when u hv salt so u move faster- not rlly LMAO)
What does sodium channel blockers do and state its clinical applications
Slows the activity of neurons by affecting the depolarization
Used in local anesthetic agents and anti epileptic drugs
What toxin does fugu fish contain and how does it affect the body
Tetrodotoxin, blocks sodium channels and causes dizziness, weaknes to paralysis, brainstem dysfunction, perioral tingling
What is a synapse
A junction where one neuron communicates with another cell/ neuron/ musccle cell/ gland
What is synaptic transmission
process of transmission of impulse from neuron (presynaptic) across a cleft to receiving (postsynaptic) target cell
Explain the process of cholinergic synapse
- An action potential arrives and depolarizes the axon terminal
- Extracellular calcium enters the axon terminal, triggering the exocytosis of acetylcholine (ACh)
- ACh binds to receptors and depolarizes the postsynaptic membrane
- ACh is removed by AChE (acetylcholinesterase)
Name the other types of neurotranmitters
Norephinephrine (NE)
Dopamine
Serotonin
Gamma aminobutyric acid (GABA)
What are the three meninges surrounding the CNS
Dura mater
Arachnoid
Pia mater
What is the function of the meninges
Provides physical stabilty, protection and shock absorption
What does the epidrual space between the spinal dura mater and walls of vetebral canal contain
loose connective and adipose tusse
What is the injection site for anethesia
The dura mater
Which layer contains the CSF
Sub Arachnoid Space
What is the pia mater made of
A mesh of collagen and elastic fibers and is bound to underlying neural tissue
What is meningitis and its symptoms
Inflammation of meningeal layers caused by bacteria, fungi etc.
Fever. neck stiffness and photophobia
How is meningitis diagnosed
Spinal tap (between L3 and L4) or lumbar puncture and examination of CSF
How can head injury affect the meningeal spaces
May cause bleeding of haemorrhage in the meningeal spaces
Where is spinal anesthesia given
In the subarachnoid space before any surgery
Where is epidural anesthesia given
In epidural space for painless labour
Name the three meningeal spaces
epidural
Subarachnoid
Subdural
What are the two types of roots that each spinal nerve contain and what type of axons does each contain
Dorsal (afferent/ sensory)
Ventral (efferent/ motor)
What type of nerve is the spinal nerve
mixed nerve
What are the two types of matter in the spinal cord
White matter, contains myelinated and unmyelinated axons
Gray matter, contains neuron cell bodies, neuroglia, unmyelinated axons and has projections (gray horns)
What is paraplegia
partial or total loss of motor or sensory function of the lower extremities
Injury is at T1-12 or L1-5 regions
What is quadriplegia
partial or total loss of motor and sensory function of btoh upper and lower limbs
Injury is at C1-7
What neurotransmitter produces a calming effect
GABA
