Chapter 11 Nervous Tissue
What is Saltatory conduction velocity?
(jumping) much faster. They are myelinated and impulses can jump between myelin sheaths. Helps prevent impulse leaking! Gaps between them are nodes
Describe Purines
ATP chemical messenger, Adenosine, Caffeine is adenosine blocker (sleepy tired build up)
What are the 7 chemical classes of neurotransmitters?
Acetylcholine (AcH) Amines Biogenic Amino Acids Peptides Purines Gases and Lipids Endocannabinoids
What are the 4 types of Central Nervous Neuroglia cells?
Astrocytes Ependymal Cells Oligodendrocytes Microglia
What are the 4 types of neuroglia cells in the central nervous system?
Astrocytes, Ependymal , Oligodendrocytes, and Microglia
What are the 2 types of conduction velocity?
Continuous Saltatory
What is serial Processing?
Front pint a to be and so on. 1 pathway. Path to a specific destination. Domino effect. Specific or patterned response reflexes! (1 stimulus = same outcome)
Describe Gases and Lipids
Gastro-transmitters can help dilate blood vessels. Nitric Oxide
What are the 3 structural classifications of neurons?
Multipolar, Bipolar, and Unipolar
What are Action Potentials?
Need stronger signals, have further to travel entire length of axon which is a long distance.
Describe a Schwann Cell
Neuroglia Cell of the peripheral nervous system forms myelin sheath wraps around individual neurons of diff sections
What is the absolute refractory period?
Refractory- can't undergo another round until fully reset! Neurons can only respond to 1 stimuli at a time.
What are the 4 stages of action potential generation?
Resting Depolarization Re-polarization Hyper-polarization
What are the 2 types of Peripheral Nervous Neuroglia cells?
Satellite Cells Schwann Cells
What are the two types of neuroglia cells in the peripheral nervous system?
Satellite, and Schwann
What forms the myelin sheath in the PNS?
Schwann cells
What are the 3 functional classifications of neurons?
Sensory Motor Interneuron
What are the 3 overlapping functions of the nervous system?
Sensory Input, Integration, and Motor Output
What are the 2 divisions of the peripheral nervous system?
Sensory and Motor
What are Graded Potentials?
Short distance signal from dendrites to cell body does not have to be so strong.
What is the Re-polarization stage of AP generation?
Sodium channels close restore resting potential (-70)
What are some characteristics of neurons?
Structural units of nervous system, impulse generating and conducting cells- Large cells (can stretch entire length of nerve), Extreme longevity, downside-amitotic - doesn't undergo mitosis. High metabolic rate.
What is the Resting stage of AP generation?
Where all channels are closed -70. No ions move through voltage gated channels sodium outside cannot come in.
Describe the Sensory division of the peripheral nervous system
afferent ARRIVING send impulses to central nervous system somatic and visceral sensory have nerve fibers, conducts impulses from receptors to the CNS
Describe Sensory
afferent send impulses towards CNS
Describe Amines Biogenic
amino acid based dopamine, serotonin, emotional behaviors any imbalance associated with mental illness. Epinephrine (adrenaline)
Describe Endocannabinoids
bodies natural THC cannabinoids, liquid soluble stay in fat cells
What is the Central Nervous System?
brain and spinal cords interprets signals
What are the collections of neuron cell bodies in the PNS called?
called ganglia appear along the nerves
What are the collections of neuron cell bodies in the CNS called?
called nuclei appear as pockets of gray mater in the brain
What is parallel processing?
can have different outcomes from same stimulus. Input travels along several pathways. 1 stimulus = multiple different outcomes.
What is sensory input?
can receive sensory inputs from environment (see's the red light)
What is the myelin sheath?
composed of myelin formed by neurolgia cell. White fatty portion marble look protects axons, increase speed.
What is the Peripheral Nervous System?
cranial nerves, spinal nerves, ganglia, sensory motor signals travel to and from
What 2 factors influence conduction velocity?
diameter of axon - thicker can carry faster or more signals degree of myelination
Describe the Motor division of the peripheral nervous system
efferent exiting away from CNS to effector organs (muscles or glands) motor nerve fibers conducts impulses from the CNS to effectors
Describe Motor
efferent signals to effector organs
Describe a biopolar neuron
has 2 processes 1 Axon, and 1 Dendrite. Primarily associated with sensory receptors found in retina of eye olafactory (vision and smell)
Describe Interneuron
in CNS integration
Describe the Autonomic Nervous System
involuntary muscles or glands conducts CNS to cardiac muscles, smooth, and glands
What are axons?
long tails of neuron output of secretory regions. send signals out to other neurons.
Describe Amino Acids
makeup all proteins, Glutamate, Aspartate, Glycine, GABA
What is Motor Output?
movement activate effector organs --> muscles and glands (tells effector organs like muscles to legs to stop car at red light)
Describe a multipolar neuron
multiple ends that stick out from cell body. 1 Axon, many dendrites. Found everywhere most common. Ex. Muscles
What is white matter?
myelinated (white appearance) fatty look
What is the resting membrane potential (RMP)?
negative 70 millivolts - more negative inside than outside when not stimulated RESTING more + charged ions outside
Describe Astrocytes
neuroglia cell in central nervous system, Star shaped maintain blood/brain barrier. Supportive brace neurons, reach out grab them, wrap around capillaries reg. environment
Describe Microglia
neuroglia cell in central nervous system, immune system cells monitor patrol and eat invaders and defensive cells
Describe Ependymal Cells
neuroglia cell in central nervous system, line fluid filled cavity in spinal cord and ventricles of brain
Describe Oligodendrocytes
neuroglia cell in central nervous system, wrap around neurons and form myelin sheaths around CNS nerve fibers. protect and support wrap around multiple
Describe a Satellite Cell
neuroglia cell of the peripheral nervous system, surround body cell, cell portion regulate neuro transmitters
What forms the myelin sheath in the CNS?
oligodendrocytes
What happens at the threshold point of AP generation?
once sodium starts to move in (-55) triggers positive feedback causes more sodium channels to open and causes snow ball effect. Spike of action potential NO GOING BACK
Describe a unipolar neuron
only has 1 process (signal) coming of cell body forks from there into distal (sensory) and proximal (Central) enter CNS sensory receptors
What are dendrites?
receiving regions receive impulses/signals. neuro transmitters from other neurons are pretty short.
What is the Hyper-polarization stage of AP generation?
refractory period where you don't get another stimulation before we are fully reset. Prevents another AP
Describe Acetylcholine (AcH)
released @ neuromuscular junction, stimulate muscle contraction
Describe Peptides
short protein chains. Pain signals, endorphins, gut brain peptides
What is Continuous conduction velocity?
slow conduction in un-myelinated axon has to cycle through depolarization and re-polarization all along axon
What is the Depolarization stage of AP generation?
sodium channels open. Sodium influx causes inside to become less negative. Flipping polarity. Sodium flowing inside cell.. Have spike of action cell.
What is Integration?
takes place in central nervous system have to understand systems (tells brain to slow down at red light)
What generates RMP?
the differences in chemical ionic makeup in intra (ICF) and extra cellular fluid (ECF)
What is gray matter?
the nuclei in CNS not myelinated
Describe the Somatic Nervous System
voluntary nervous system, voluntarily controlled skeletal muscles. Conducts CNS to skeletal muscles