nervous system and neurons Flashcards
what three things make up the nervous system?
- brain
- spinal cord
- nerves throughout the body
what is coordinated by the brain sending information throughout the body?
bodily functions, muscle movements, and the transmission of sensory information are coordinated by the brain sending information throughout the body and peripheral nerves sending information to the brain.
what are the two nervous systems in the body?
the nervous system is the body’s communication and control network. it consists of the central nervous system and the peripheral nervous system.
what does the central nervous system do?
the central nervous system functions as the body’s information processing and control centre.
what is the central nervous system made up of?
it includes the brain and spinal cord.
what does the peripheral nervous system do?
the peripheral nervous system passes information between the central nervous system and the rest of the body.
what does the peripheral nervous system contain?
the spinal nerves and the cranial nerves. the spinal nerves will spread out to supply the extremities and the rest of the body.
what does the nervous system do?
the nervous system coordinates the actions of skeletal muscles and internal organs, and receives and processes sensory information from the environment. the nervous system also controls blood vessel dilation and gland secretion.
what nervous system includes special sense organs (eyes, ears, structures in the nose area and the tongue).
peripheral nervous system
what are the structures of the central and peripheral nervous system formed from?
nervous tissue. this nervous tissue includes types of cells called neurons and supporting cells called neuroglia.
what are neurons?
neurons are nervous system cells that can conduct electrical signals and pass information rapidly throughout the body.
what does a neuron consist of?
a typical neuron consists of a cell body or soma, many dendrites, and one axon.
what are dendrites?
dendrites are short, tapering, and branched nerve processes that receive chemical signals from other neurons and transmits them toward the cell body.
what does the cell body contain?
the cell body contains a nucleus, organelles, free ribosomes, and Nissl bodies that synthesize proteins; neurofibrils that provide support; and microtubules that move materials down the axon.
what is the axon?
the axon is a long, thin, and cylindrical nerve process that generates nerve impulses and transmits them to its axon terminals, which release neurotransmitters to another neuron, a muscle fibber, or a gland cell.
what does the myelin sheath do?
when a myelin sheath surrounds the axon, it provides insulation that increases conduction speed. not all axons are myelinated
how are neurons classified?
neurons can be classified by structure
what neurons have one axon and many dendrites extending from the cell body?
multipolar
what neurons are located in special sensory organs. these neurons have one axon and one dendrite
bipolar neurons
in what axon does the axon split into two branches that attach to the cell body?
unipolar neurons are also sensory neurons.in this type of neuron, the axon splits into two branches that attach to the cell body
when is a neuron in a state of resting potential?
when a neuron is not transmitting a signal, it is in a state of resting potential.
what causes positively charged ions to entre the cell, depolarizing the cell membrane.
a stimulus
what are neurotransmitters
chemical released as synapses and regulate the activity of muscles, glands and other neurons.
what do excitatory neurotransmitters do?
encourage the transmission of an action potential, while inhibitory neurotransmitters inhibit transmission.
what is acetylcholine
acetylcholine is a widespread neurotransmitter found in the CNS and a neuromuscular junctions between peripheral nerves and muscles.
what do norepinephrine and epinephrine do?
norepinephrine and epinephrine function as both hormones and neurotransmitters, mainly in the CNS. they are produces in the adrenal glands and secreted into circulation.
what is dopamine
dopamine is a brain neurotransmitter that regulates skeletal muscle tone and emotional responses.
what does grey matter consist of?
neuron cell bodies
what does white matter consist of?
myelinated axons
axon hillock
A structure that initiates action potentials.
axon
A long, thin, cylindrical nerve process that generates nerve impulses.
Axon terminal
A structure that releases neurotransmitters, chemicals that have an excitatory or inhibitory effect on their target (another neuron, a muscle fibre, or a gland cell)
soma
The cell body, which contains a nucleus and organelles
Dendrites
Short, tapering, and branched nerve processes that receive chemical signals from other neurons and transmit them toward the cell body.
what is the net charge outside a resting neuron?
positive
what is the peripheral nervous system made from?
The peripheral nervous system is made up of the cranial nerve, spinal nerves and sensory organs.
what is a neuron made up from?
A typical neuron consists of soma, many dendrites, and one axon.
state
The brain and spinal cord make up the central nervous system (CNS). The spinal cord transmits signals to and from the brain and commands reflexes, immediate responses that don’t require the brain’s input. The brain connects perceptions to complex thought, memory, and emotion
what is the net charge inside a resting neuron?
negative
