CNS & Nervous systems Flashcards
What is the function of Nervous System
Sensory Function
Integrative Function
Motor Function
what does the sensory function do ?
detects internal ( Blood acidity) & External stimuli ( rain landing on arm)
What does the integrative function do ?
process sensory information &
Makes decisions for appropriate responses
what does the motor function do ?
activates effectors through cranial and spinal nerves & Stimulates effectors –> cause muscle to contract and glands to secrete
What is in the CNS
Brain & Spinal Cord
What is in PNS
Nerves, Cranial Nerves, Spinal nerves, ganglia, sensory receptors,
what do Cranial Nerves do ?
Emerge from brain
what do spinal nerves do?
emerge from spinal cord
what are ganglia?
small clusters of nervous tissue, consisting of neuron cell bodies that are located outside of brain
what are sensory receptors ?
Nervous system structures that monitor changes in the external and internal environment
what are neurons ?
form complex networks within brain and spinal cord.
Function : Controlling muscle activity, regulating glandular secretions, thinking, remembering, sensing
What are Neuroglia?
Support, Nourish , protect neurons, and maintain homeostasis in interstitial fluid.
Cell body of Neuron?
Nucleus surrounded by cytoplasm and many typical cellular organelles ( Mitochondria , Golgi complex )
what do Nissl Bodies do ?
Its where protein synthesis occurs.
- it is used to replace cellular components
- Regenerates damaged axons in pns
What are dendrites ?
receiving or input portions of neuron
What is the axon?
propagates impulses toward another neuron, muscle fiber, or gland cell
What are schwann Cell?
Form Myelin sheath around axons in PNS
What is the Meylin Sheath?
Multilayred lipid and protein layer that covers the axons.
Electrically insulates the axon and increase speed of impulse conduction.
What is the neurolemma?
Layer of the schwann cell that encloses the myelin sheath
What are the Node of Ranvier ?
gaps in myelin Sheath , between cells
Types of Neuroglia in CNS?
- Microglia
- Phagocytize microbes and damaged nervous tissue - Ependymal Cells
- produce and assist in the circulation of cerebrospinal fluid - Astrocytes
- help maintain appropriate chemical environment for the generation of impulses - Oligoderocytes
- form and maintain myelin sheath around CNS axons
Types of Neuroglia in PNS?
- Schwann Cells
What is gray matter ?
Unmyelinated axons superficial in brain
* Deep in Spinal Cord*
What is the White matter?
Presence of myelinated axons from oligodendrocytes
- Deep in brain*
- Superficial in spinal cord *
what is agraded Potential ?
Origin: located in dendrites and cell body
Types of Channel : Ligand-gated or mechanically gated ion channel
Conduction : Short communication
Size: Less than 1 mV to More than 50 mV
Duration : Long
Polarity : Hyper-polarizing OR Depolarization
Refractory Period : Not present
what are action potentials?
Origin : Arise at trigger points and propagate along axon
Type of Channel: Voltage - gated channel for Na+ & K+
conduction : Communication over longer distances
Size : all or none , about 100 mV
Duration : shorter
Polarity : Depolarizing phase
—> repolarizing phase –> Returns to resting membrane potential
Refractory period : Present
What is the function of cerebrospinal fluid ?
Protects the brain and spinal cord against chemical and physical injury. And Circulation
What is the formation of the cerebrospinal fluid?
- lateral ventricle
- third ventricle
- Fourth ventricle
4.
What is the function of the brain stem ?
Relay center for processing and controlling involuntary reflexes for vision
