Lecture 9 & 10 Flashcards
Cells with electrical activity
Neurons
A network of neurons and support (glial) cells
Nervous system
How signals travel in nervous system
Signals pass from sensory receptors/neurons, and are integrated, new signals are generated and conducted through neurons to the effector cells.
Info from internal/external environment to brain
Sensory neuron
Effector cell
CNS -> body
Motor neuron
Neurons that are entirely in CNS
Interneurons
What does the nervous system help animals do?
Regulate muscle contraction (movement)
Regulate secretions from glands (hormone, enzymes, saliva, etc.)
Gather info about external and internal environment -> maintain homeostasis (detect pain, pressure, chemical concentrations)
Stimulate thirst, hunger, other survival mechanisms
2 key characteristics of central nervous system
Centralization & cephalization
Neurons organized in to a central integrating area
Brain and spinal cord
Centralization
Concentration of nervous structures into one end of the body towards the head
Brain
Most animals walk on all 4s
Cephalization
Afferent
To CNS
Efferent
Away from CNS
Spinal cords 2 types of neural circuits
Local
Ascending/descending
Cell bodies, synapses, unmyelinated axons, outside region of brain
Grey matter
Tracts of myelinated axons, inner portion of brain
Ascending and descending
White matter
Bundle of myelinated axons in the CNS
Tract
Groups of nerve cell bodies in the CNS
Nuclei
A bundle of neuron axons in the peripheral nervous system
Nerve
A grouping of cell nerve bodies in the peripheral nervous system
Ganglion
Any nervous tissue located outside of the brain and spinal cord
Peripheral nervous system
2 key divisions of PNS
Somatic & autonomic
“Processing center” where incoming messages go and outgoing messages originate
Cerebral cortex
Cell able to generate and propagate an electrical signal
Neurons
4 key parts of the neuron
Dendrites- input
Cell body(soma) - integration (processing)
Axon - transmission
Pre-synaptic terminals - output
Compared to the endocrine system…the nervous system is _____ and _____
Fast & addressed
Resting membrane potential
-65mV
