The Nervous System Pt. 1 Flashcards
Functions of the Nervous System include?
- Sensory
-Detecting changes in environment (in body or external env.) - Integration
-Processing and decision making (takes sensory info; decides what to do then sends to motor) - Motor
-Telling the body what to do in response (do intended action)
What makes up the CNS and the PNS?
CNS: Brain and Spinal Cord
PNS: Cranial Nerves, Spinal Nerves, Ganglia, Enteric plexuses in small intestine, sensory receptors in skin
Ganglia are 2 nerves that meet and pass signal btwn them
What are afferent and efferent neurons?
Afferent = Nerves that take things towards an organ (sensory)
Efferent = Processes what was received and sends the signal out (Motor)
How does the somatic nervous system work?
- Somatic and special sensory receptors send signals to the Central Nervous System
- Brain and spinal cord make a decision and send it the motor
- Somatic motor neurons (motor signals) which are voluntary allow for movement of Skeletal muscle
Somatic nervous system is in control of your voluntary actions; movememt of muscles
How do the parasympathetic and sympathetic nervous system work?
- Visceral sensory receptors and sensory neurons detect subconscious changes (BP change)
- Central Nervous System employs Autonomic Motor Neurons (involuntary)
- This causes the sympathetic or parasympathetic N.S. to act on the smooth muscle, cardiac muscle, glands
Fall under the Autonomic Nervous System (happens involuntarily)
How does the Enteric System work?
- Enteric sensory receptors and neurons in the GI Tract and enteric plexuses (sense changes like pressure, chemical, nutrient level etc.)
- Enteric Motor Neurons in enteric plexuses sends signals to Smooth muscle, glands, and endocrine cells of GI Tract
Autonomic N.S. can override Enteric Nervous System in emergency situations
What are the main components of a Neuron’s structure?
Cell Body, Dendrites and the Axon
Dendrites responsible for directing electrical nervous signals into the cell body
What are myelin sheaths?
Fatty tissue around the axon which speeds up the transfer of signals
What are non-nervous cells?
They make up a part of the nervous tissue but do not have the same functions as neurons, rather they are helper cells with different functions of their own varying in number too
A.K.A Glial cells
What glial cells make up the Central Nervous System?
- Fibrous & Protoplasmic Astrocytes
- Oligodendrocytes
- Microglial Cell
- Ependymal Cell
Functions of Protoplasmic & Fibrous Astrocytes?
Fibrous: Acts as glue; very structural
Protoplasmic: Positioned btwn blood capilary and neuron & makes sure nothing happens to the neuron
Function of Microglial cells?
Small in numbers but is capable of destroying viruses and bacteria infiltrating the CNS
Functions of Ependymal Cells?
Cuboidal Epithelial Cells; line specific cavities of the brain (ventricles) & spinal cord
Produce (possibly), monitor and assess circulation of C.S.F.
Functions of Oligodendrocytes
Cytoplasmic extensions shoot out which are responsible for creating myelin sheaths
What’s different about Non-nervous cells in the PNS compared to the CNS
Non-nervous cells in the peripheral nervous system does not have microglial cells because it’s more external and immune cells are available to fight off pathogens
