Structure for neuro Flashcards
What are the key components of a nerve
Axon
Myelin sheath
Nodes of Ranvier
Fascicle
Endoneurium
Perineurium
Epineurium
Vasa Nervorum
Nerve Endings
What is an axon?
A long slender projection of a neuron that conducts electrical impulses
What is the epineurium
The outermost layer encapsulating the entire nerve structure
What is the myelin sheath
A layer of fatty substance that insulates the axon
What are nodes of ranvier
gaps in myelin sheath facilitating saltatory conduction
What are fascicles
A bundle of nerve fibres enveloped by the perineurium
What is the endoneurium
A thin layer of connective tissue surrounding individual nerve fibres
What is the perineurium
A protective sheath encasing a bundle of fascicles
What is the vasa nervorum
Small blood vessels supplying nutrients and oxygen to the nerve tissues
What are nerve endings
Specialised structures facilitating communication with other structures
What is the function of the axon
Transmits electrical signals from the neuron’s cell body to synapses
What is the function of the myelin sheath
Facilitates rapid transmission of electrical signal and protects the axon
What is the function of the nodes of ranvier
Allows for faster transmission of nerve impulses by facilitating saltatory conduction
What is the function of fascicles
Groups multiple nerve fibres together to form a structural unit within the peripheral nerve
What is the function of the endoneurium
Provides support and protection to individual nerve fibres
what is the function of the perineurium?
Offers protection to groups of fascicles and maintains the blood-nerve barrier
What is the function of the epineurium
Offers overall protection and support to the nerve structure
What is the function of the vasa nervorum
Facilitates the supply of nutrients and oxygen to the nerve tissues
What is the function of nerve endings
Transmits sensory information to the CNS or initiates motor responses in peripheral tissues
What are the divisions of the peripheral nervous system (PNS)
Somatic nervous system
Autonomic nervous system
What are the subsystems of the somatic nervous system
Sensory neurons (afferent)
- exteroreceptive neurons
-proprioceptive neurons
- interoceptive neurons
Motor neurons (efferent)
- Alpha motor neurons
- Gamma motor neurons
What are the subsystems of the autonomic nervous system
Parasympathetic nervous system
- CranioSacral Division
- PreGanglionic Neurons (Para)
- PastGanglionic Neurons
- Cholinergic Receptors
Sympathetic Nervous System
- Thoracolumbar Division
- PreGanglionic neurons
- PostGanglionic neurons
- Adrenic Receptors
Enteric Nervous System
- Myenteric Plexus (Auerbach’s Division)
- Submucosal Plexus (Meissner’s Plexus)
What are areas / actions of the sympathetic NS (roots)
Dilates pupils (cervical)
Inhibits saliva production (cervical)
Dilates bronchia (cervical)
Rises heart rate (thoracic)
Inhibits the activity of the digestive system (thoracic)
Inhibits the activity of the pancreas (thoracic)
Inhibits the gallbladder (thoracic/lumbar)
Stimulates the adrenal medulla to release adrenaline and noradrenaline (lumbar)
Relaxes urinary bladder (lumbar)
Stimulates orgasm in genitals of man and woman (sacral)
Parasympathetic Nervous system actions (roots)
Constricts pupils (cranial)
Increases saliva production (cranial)
Reduces the heart rate (cranial / cervical)
Constricts bronchia
Stimulates the activity of digestive organs
Stimulates the activity of the pancreas
Stimulates the gall bladder
Constricts urinary bladder
Stimulates erections of genital of man and woman
What are the effects of the myelin sheath
Membranes aid information to be transmitted
The opening and closing of ion channels at nodes of Ranvier aid the continuation of signal
