Week 7 Nervous Tissue Flashcards
(30 cards)
What are the main functions of the nervous system?
Coordination, control, information processing, perception, emotions, memory, and thinking.
What are the two main divisions of the nervous system?
Central Nervous System (CNS) and Peripheral Nervous System (PNS).
What are the two major cell types in nervous tissue?
Neurons and glial cells.
What is the function of neurons?
Generate and propagate action potentials (electrical signals).
What is the function of glial cells?
Support, maintain the extracellular environment, and assist neuron function.
What do dendrites do?
Carry signals toward the cell body – input.
What do axons do?
Carry signals away from the cell body – output.
What is the myelin sheath made of?
Lipid-rich covering produced by Schwann cells (PNS) and oligodendrocytes (CNS).
What are nodes of Ranvier?
Gaps in the myelin sheath that enhance signal conduction.
What happens at the synapse?
Neurotransmitters are released by the presynaptic neuron and bind to receptors on the postsynaptic neuron.
Which channels are responsible for action potentials?
Voltage-gated sodium and potassium channels.
What maintains the resting membrane potential?
Na+/K+ pumps and leakage pores.
What is a multipolar neuron?
Neuron with multiple dendrites and one axon – most common type.
What is a bipolar neuron?
One dendrite and one axon – found in sensory organs.
What is a unipolar neuron?
Axon and dendrite fused into one process – mostly sensory neurons.
What is an afferent neuron?
Sensory neuron carrying information toward the CNS.
What is an efferent neuron?
Motor neuron carrying information away from the CNS to effectors.
What are interneurons?
CNS neurons involved in local processing and reflexes – make up 99% of neurons.
What does a Meissner corpuscle detect?
Touch and pressure.
What does a Pacinian corpuscle detect?
Deep pressure and vibration.
What do free nerve endings detect?
Pain and temperature.
What is the function of astrocytes?
Support neurons, form blood-brain barrier, regulate environment, and aid repair.
What do ependymal cells do?
Line brain ventricles and produce cerebrospinal fluid (CSF).
What is the function of oligodendrocytes?
Form myelin sheath in the CNS.
