Nervous system Flashcards
The main parts of a neuron?
Dendrites, Body, and Axon
Describe the path sensory neurons take?
From the body towards the CNS, afferent
Describe the path motor neurons take?
Away from the CNS towards the body, efferent
What do interneurons do?
Connects impulses from sensory to motor neurons
What does the axon do?
Processes that transmit impulses away from the neuron cell body
what do dendrites do?
processes or projections that transmit impulses to the neuron cell bodies
What is the node of ranvier?
periodic gap in the insulating sheath (myelin) on the axon of certain neurons that serves to facilitate the rapid conduction of nerve impulses
What is the myelin sheath?
white fatty substance formed by Schwann cells. It is an insulating layer that allows electrical impulses to transmit quickly and efficiently along the nerve cells. Play vital role in maintaining the peripheral nervous system.
What is Neurilemma?
(Sheath of Schwann cell) Only available in the PNS neurons
What are schwann cells?
Glia cell that produces myelin in the peripheral nervous system
what is and function of astrocytes?
Glia cells that are apart of homeostasis and blood brain barrier; doesn’t allow toxins to enter brain
what is and function of oligodendrocyte?
Glia cell that produces myelin in the central nervous system
what is and function of microglial cell?
Regulates brain development, maintenance of neural network; injury repair
What are nerves?
a collection of nerve fibers (axons) in the peripheral nervous system
What are tracts?
a collection of nerve fibers (axons) in the central nervous system
What is white matter?
Tissue composed primarily of myelinated exons (nerves and tracts)
What is grey matter?
Tissue composed primarily of cell bodies and unmyelinated fibers
What do ascending tracts do?
conduct sensory impulses to the brain
What do descending tracts do?
conduct motor impulses from the brain to motor neurons reaching muscles and glands
What is the resting potential of a cell?
Outside:+ more sodium (Na)
Inside:- more potassium (K)
What is depolarization?
When sodium floods into the cell
What is the action potential?
Outside:- more potassium (K)
Inside:+ more sodium (Na)
What is repolarization?
When the potassium floods outside the cell
In an unmyelinated fiber, describe the electrical current?
A nerve impulse (action potential) is a self-propagating wave of electrical disturbance.
What is saltatory conduction?
In a myelinated fiber, the action potential “jumps” around the insulating myelin in a rapid type of conduction
Benefits of saltatory conduction?
Increases rate of action potential
increases impulse speed
conserves energy, as depolarization only occurs at the nodes of ranvier
What is a synapse?
a place where impulses are transmitted
Describe chemical synapse?
The vesicle fuses with the cell membrane and opens up. released from axon terminals (of a presynaptic neuron) into a synaptic cleft. Neurotransmitters bind to receptors on the postsynaptic neuron.
Describe electrical synapse?
When the plasma membrane of
two neurons are fused by gap junction (protein/connexins). allowing the action potential to pass through.
What does the medulla oblongata allow?
Breathing, swallowing, heart rate, blood pressure, it connects the brain to the spinal cord
What does the pons allow?
Sleep and arousal, dreams, facial expressions, breathing
What does the midbrain do?
All parts of the brainstem?
Medulla oblongata, pons, and midbrain
The outer part of the spinal cord Is composed of…?
White matter made up of many bundles of exons called tracts.
The interior part of the spinal cord Is composed of…?
gray matter made up mainly of neurons dendrites and cell bodies
Covering of the brain?
Cranial bones and cerebral meninges
Covering of the spinal cord?
Vertebrae and spinal meninges
Layers of the menninges?
Pia mater (inner)
Arachnoid mater (middle)
Dura matter (outer)
Fluid spaces?
Subarachnoid spaces of meninges
Central canal inside cord
Ventricles in the brain
Central nervous system?
Brain and spinal cord; responsible for sensory activities
Peripheral nervous system?
Cranial and spinal nerves; brings messages to and from the CNS to the rest of the body
Somatic nervous system?
From the peripheral nervous system. Responsible for voluntary movements (muscle movements)
Autonomic nervous system?
From the peripheral nervous system. Responsible for involuntary actions (heart beat, pupil dilation, etc…)
Sympathetic nervous system?
First from the peripheral nervous system and secondly from Autonomic nervous system. Responsible for fight or flight response.
Parasympathetic nervous system
First from the peripheral nervous system and secondly from Autonomic nervous system. Responsible for rest and relax actions (digestion, etc…)
The list of systems of the nervous system.
The central nervous system and the peripheral nervous system
Peripheral nervous system –> somatic nervous system and autonomic nervous system
autonomic nervous system –> sympathetic nervous system and parasympathetic nervous system
Cranial nerves?
- Only = Olfactory
- One = Optic
- Of - Oculomotor
- The = Trochlear
- Two = Trigeminal
- Athletes - Abducens
- Felt - Facial
- Very = Vestibulocochiear
- Good = Glossopharyngeal
- Victorious = Vagus
- And = Accessory
- Healthy = Hypoglossal
Cranial nerve function?
conducts impulses between the brain and structures in the head
and neck and in the thoracic and abdominal cavities
