Nervous system organization (Oct15/16)

what is ganglia

a group of neuron cell bodies in the PNS

what is a nerve

many axons bundled together in the PNS

what is a synapse

the junction between a neuron and another cell allowing the “transmission of info”

what is a afferent fibre

axons carrying sensory info from the PNS to CNS

what is a efferent fibre

axons carrying motor info from the CNS to muscles

what is a sensory neuron

neurons that detect/transmit sensory stimuli from the environment/body to the CNS

what is a motor neuron

neurons that transmit commands from the CNS to muscles/glands

what is a interneuron

neurons in the CNS that connect sensory/motor neurons n

what are neuroglia

supporting cells that protect the neuron and are non-excitable

what is apart of the structural division of the nervous system

the central nervous system (CNS) and peripheral nervous system (PNS)

what does the CNS consist of

the brain and spinal cord

what does the PNS consist of

everything other than the brain and spinal cord

what does the functional division of the nervous system consist of

sensory (afferent) nervous system and motor (efferent) nervous system

what does the sensory nervous system do

sends stimuli to the CNS, “arrives” at the brain

what does the motor nervous system do

sends signals from the CNS to muscles , “moves away”

what do somatic efferent neurons innervate

voluntary skeletal muscles

what do somatic afferent neurons inntervate

skin, skeleteal muscle/joints

what do visceral efferent neurons innervate

smooth/cardiac muscle, and glands

what do visceral afferent neurons innervate

internal organs, blood vessels

what are the types of cells in the CNS

astrocytes, ependymal, oligodendrocyte, microglia cells

what do astrocyte cells do

• gives strucutral support

• helps regulate ion/electrolyte composition of surrounding tissues

• helps establish blood brain barrier blood-brain

what do ependymal cells do

produces cerebral spinal fluid

what do oligodendrocytes do

produces myelin sheaths which insulates neurons and makes action potentials travel faster

what do microglia cells do

gets rid of debris, regulates ion composition of nervous tissue

what are the neuroglia cells in the PNS

schwann and satellite cells

what do shwann cells do

produces myelin sheath

what do satellite cells do

regulates ions, nutrients, and ion composition

what does a chemical synapse do

• has synaptic vesicles which relay impulses

• moves in 1 direction

what does a electrical synapse do

• is linked to a postsynaptic cell by gap junctions

• moves in any direction

how are chemical and electrical synapses different

chemical synapses use neurotransmitters while electrical synapses use ions