Lecture 11: Neural Tissue Flashcards
Neurons
Cells that send and receive signals
Where Do Neurons Send/Receive Signals To/From?
1 region of the body to another
Neuroglia (glial cells)
Cells that support and protect neurons
Central Nervous System Consists Of…
Brain
Spinal Cord
Peripheral Nervous System Consists Of…
All neural tissues outside of CNS
Afferent Division of Peripheral Nervous System
Brings sensory information to CNS from receptors in peripheral tissues (sensory neurons),
Periphery to spinal cord and brain
Efferent Divison of Peripheral Nervous System
Carries commands from CNS to effector tissues like muscles and glands (motor neurons),
CNS to peripheral
S.A.M.E
Sensory Afferent
Motor Efferent
Somatic Nervous System of Efferent Division of PNS
Controls voluntary and involuntary skeletal muscle contractions and reflexes
Involuntary Skeletal Muscle Contractions
Not under conscious control (reflex)
Autonomic Nervous System of Efferent Division of PNS
Controls smooth muscle, cardiac muscle and glandular secretions at the subconscious level
Nerve
Bundle of neurons/axons
Cell Body Of A Neuron
Nucleus and perikaryon,
Location of most organelles
Perikaryon Of A Neuron
Cytoplasm of neuron cell body,
Contains organelles
Dendrites Of A Neuron
Receive neurotransmitters from other neurons
Axoplasm Of An Axon
Cytoplasm
Axolemma Of An Axon
Plasma membrane
Axon Hillock
Axon attaches to cell body,
Must reach threshold to continue sending action potential to axon
Telodendria
End of axon branches,
Synaptic terminals
Nissl Bodies
Gray matter of CNS,
Clustered areas of ribosomes and rough ER
Neurons lack ______, so no mitosis can occur
Centrioles
Ganglia
Collection of cell bodies,
In PNS
Cranial Nerves
In PNS,
Connected to brain/brainstem
Spinal Nerves
In PNS,
Connected to spinal cord
Tracts
Areas of the CNS appear white because many neuron axons are covered with myelin,
White matter of CNS
Synapse
Site where a neuron communicates with another cell
Presynaptic Cell
Sends message,
Neurons
Postsynaptic Cell
Receives message,
Neuron, muscle fiber, gland cell
Neurotransmitters
Produced in the neuron cell body,
Released at the synapse
Neurotransmitters Are Transported In ________ To _______
Vesicles,
Synaptic knob
Axoplasmic Transport
Neurotransmitters move down the axon
Anterograde Transport
Moving towards the synapse
Retrograde Transport
Moving away from synapse
Anaxonic Neuron
No obvious axon,
In brain and CNS
Bipolar Neuron
Body not near dendrites,
In eyes/ears/nose
Unipolar Neuron
Almost all sensory neurons,
Body on the side of axon
Multipolar Neuron
Cell body,
Axon,
Synaptic terminals,
Motor units
Sensory Neurons
10 million in body,
Afferent
Visceral Sensory Neurons
Monitor internal environment of body,
Unaware of
Somatic Sensory Neurons
Monitor external environment and our position in it,
Aware
Sensory Receptors
Specialized organs or free endings on dendrite end of sensory neurons
Interoceptors Of Sensory Neurons
Monitor internal organ systems and provide sensations including visceral pain, blood pH and blood O2 levels
Exteroceptors Of Sensory Neurons
Monitor outside environment and provide sensations including touch, temperature, sight, smell and hearing
Proprioceptors Of Sensory Neurons
Monitor joint and muscle position so we know the position of body,
Makes us able to maintain balance
Motor Neurons
500,000 in body,
Efferent
Interneurons
20 billion in body,
Most common,
Association neurons
Where Are Interneurons Located In Body?
Brain, spinal cord, some ganglia
Interneurons Are Responsible For…
Distributing sensory info,
Coordinating motor info,
Higher functioning (thought, memory, learning, planning)
