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)
