neurological ward Flashcards
what is the peripheral nervous system compromised of?
- intricate network of nerves that emanate from the brain and spinal cord
what does the peripheral nervous system establish?
- establishes a critical communication pathways between the central nervous system and various segments of the body
what are the two subsystems of the peripheral nervous system?
- somatic nervous system
- autonomic nervous system
what does the somatic nervous system include?
- includes nerves that are responsible for innervating the skin and muscles, actively participating in conscious and voluntary activities
what is the somatic nervous system involved in?
- involved in the integration of sensory information from periphery and muscle movements via the motor units
what does the autonomic nervous system comprise of?
- comprises of nerves that forge connections between the CNS and visceral organs e.g., heart, stomach, intestines
what does the autonomic nervous system orchestrate?
- orchestrates unconscious, involuntary physiological functions, ensuring homeostatic equilibrium within the body
what sort of physiological functions does the autonomic nervous system control?
- dilates pupils
- heart rate
- salivary production
- respiratory rate
what does the type of integration depend on?
- depends on where the nerves comes from
- i.e., dorsal or ventral root
where do somatic and sensorial nerves come from? what do they contain?
- come from dorsal root
- contain ganglions, which have interneurons
what is the ganglion important for?
- important for reflexes
what is the pathway of motor nerves?
- ventral anterior pathway
- goes directly from the spinal cord to the motor end plate
what do the motor nerves do at the motor end plates in order to relay information?
- motor nerves depolarise the motor end plate
do axons travel alone?
- no, they travel together in bundles
when bundles combine what do they form?
- when they come together they form plexus
what are the 3 main plexus?
- brachial
- lumbar
- sacral
what does the brachial plexus control?
- controls the upper limb
what does the lumbar and sacral plexus control?
- controls lower limb and pelvis structures
what does myelin sheath provide to the axon?
- provides protection and conductibility
- helps the axons to carry signals and impulses
what is an axon?
- long, slender projection of a neuron that conducts electrical impulses
what is the role of the axon?
- transmits electrical signals from the neuron’s cell body to synapses
what is the myelin sheath?
- layer of fatty substance that insulates the axon
what are the nodes of ranvier?
- gaps in the myelin sheath
what do the nodes of ranvier facilitate?
- facilitates saltatory conduction
- allows faster transmission of nerve impulses
what is a fascicle? where are they?
- bundle of nerve fibres
- enveloped by the perineurium
what do fascicles do? what do they form?
- group multiple nerve fibres together to form a structural unit within the peripheral nerve
what is the endoneurium?
- layer of connective tissue surrounding individual nerve fibres
what does the endoneurium provide?
- provides support and protection to individual nerve fibres
what is the perineurium?
- protective sheath encasing a bundle of fascicles
what does the perineurium offer?
- offers protection to group of fascicles and maintains the blood nerve barrier
what is the epineurium?
- outermost layer encapsulating the entire nerve structure
what does the epineurium offer?
- offers overall protection and support to the nerve structure
what is the vasa nervorum?
- small blood vessels supplying nutrients and oxygen to the nerve tissues
what does the vasa nervorum facilitate?
- facilitates the supply of nutrients and oxygen to the nerve tissue
what are nerve endings?
- specialised structures facilitating communication with other structures
what do nerve endings transmit?
- transmit sensory information to the CNS or initiates motor responses in peripheral tissues
what are the two subsystems of the somatic nervous system?
- sensory neurons (afferent)
- motor neurons (efferent)
what are the three subsystems of the autonomic nervous system?
- parasympathetic
- sympathetic
- enteric
how does the somatic nervous system send their information?
- in a straight, linear direction from the CNS to a particular muscle motor end plate via somatic neuron
how does the autonomic nervous system send their information?
- one stop approach
- preganglionic fibre moves towards postganglionic fibre
where does the autonomic nervous system information travel from and to?
- travels from dorsal horn
- moves to muscles, soft tissues, visceral, glands, heart
what does the parasympathetic do? what are some of the body changes?
- relaxes the body
- constricts pupils
- stimulate saliva
- constrict airway
- slow heartbeat
- contract bladder
what does the sympathetic nervous system do? what are some of the body changes?
- prepares the body for flight or fight
- dilates pupils
- inhibits saliva
- increases heartbeat
- relax airway
- relax bladder
what structure is displayed on both sides of the spinal outflow?
- paravertebral chain
what is the connection like between preganglionic and postganglionic neurons?
- spinal segments can innervate neurons within the ganglia
what can location of lesion dictate? - what is an example ?
- dictates the limitations
above L3/L4 = bladder and bowel problems as well as motor and sensory deficits
what is the direction that ganglions travel in the ANS ? where do they go?
- travels in multiple directions
- travel to vital structures and organs e.g., arteries, veins, lymphathetic system
where do all the sympathetic and parasympathetic nervous system cells travel from?
- all travel from the Dorsal home
what are segmental interactions described as? what do they occur via?
- polysynaptic
- occur through interneurons
what does the primary input signal?
- signal preganglionic neurons originating from the brainstem
how does the organisation of the ANS differ from the SNC?
- in the SNC, a single motor neuron travels from the CNS to an innervated structure e.g., skeletal muscle
what are the myelin sheath producing cells in CNS?
- oligodendrocycte
what are the myelin sheath producing cells in PNS?
- Schwann cell
what does the schwann cell provide? what is the main function?
- provides structure and immune support
- conductibility is its main function as it transfers PNS information via signals
what happens during development of the schwann cells?
- cells are transferred to the spinal cord
- some position themselves correctly and form correctly whereas others will not develop into the normal structure
what happens if signals can’t travel through the schwann cells?
- unable to get an output
- unable to get information from the PNS
what can lack of output contribute to?
- contributes to atrophy
- affects muscle health and quality
what are the three ways that injuries can be classified?
- anatomical classification
- etiological classification
- physiological classification
what are the two sub categories of anatomical classification?
- mononeuropathy
- polyneuropathy
what is mononeuropathy?
- involves damage to a single nerve of nerve group
what is an example of mononeuropathy? what does it affect?
- diabetes
- affects specific part of body e.g., lack of sensation
what is polyneuropathy?
- involves damage to multiple nerves, often symmetrically affecting both sides of the body
what does polyneuropathy cause?
- causes wide distribution of symptoms
what are the five sub categories of the etiological classification?
- traumatic
- metabolic
- infections/ inflammatory
- toxic/ chemical
what are traumatic injuries? - what are some examples?
- injuries caused by external forces and accidents
e.g., cancer, compression
what are metabolic injuries?
- injuries resulting from systemic conditions e.g., diabetes or nutritional deficiencies
what are infections/ inflammatory injuries?
- injuries caused by infections or autoimmune reactions
what are toxic/ chemical injuries?
- injuries caused by exposure to toxins or chemicals
what are the three sub- categories of the physiological classification?
- axonopathies
- myelopathies
- vasculopathy
what are axonopathies?
- injuries primarily affecting the axons of the nerves
what are myelopathies?
- injuries affecting the myelin sheath surrounding the nerves disrupting signal transmissions
what are vasculopathies?
- injuries affecting blood vessels supplying the nerves, potentially leading to ischaemic conditions
are injuries normally in one distinct category?
- no, normally a combination of all three classifications
