channels that open and close in response to outside chemical signals
metabotropic receptors
proteins that change the internal biochemistry of the cell in response to outside chemical signals
what are the two types of cells in the nervous system?
Glial cells
Neurons
Glial cells
perform a structural and support role
they also remain capable of continued cell division (mitosis)
Neurons
have two related features that other cells do not have
they can influence the flow of charges across the cell membrane, and use this property to manage the receipt, processing, and sending of information.
Second, they can often have voltage-gated ion channels, that aid in the manipulation of charges.
True or False
The nervous system generates chemical potentials to regulate body activities.
False
The nervous system generates electrical potentials to regulate body activities.
True or False
The nervous system detects changes in the body's internal and external environments, interprets the changes, and responds by causing muscular contractions or glandular secretions.
True
The nervous system is a prime example of how the body maintains __________.
Homeostasis
In most animals the entire __________ _______ is devoted to homeostasis.
nervous system
Regardless of whether it is positively or negatively controlled, what three elements are required in a homeostatic loop?
receptor
control center
effector
Receptor
Monitors controlled condition
Part of nervous system (Sensory)
Control center
Receives input and provides output
Central nervous system (brain and spinal cord)
Effectors
Brings about change in controlled condition
Part of nervous system (muscles and glands)
Where are sensory receptors located?
surface of the skin
Taste buds of the mouth
retina of the eye
and many other places
The effectors of the brain are...
smooth muscle
cardiac muscle
skeletal (volentary) muscle
glands
Afferent pathways
pathways into the central nervous system
sensory is equivalent to afferent
Efferent pathways
pathways out of the central nervous system
motor is equivalent to efferent
Sensory information is received in the internal or external environment and, through a process called __________, converted to a form the nervous system can use
transduction
Peripheral nervous system (PNS)
Cranial nerves
spinal nerves
ganglia
enteric plexi
sensory receptors
Central nervous system (CNS)
the brain and the spinal cord
What are the two categories of effectors ?
Autonomic nervous system (ANS): effectors that are controlled automatically
Somatic motor system: effectors that we control consciously.
Autonomic nervous system (ANS)
comprises those effectors not under conscious control (does not include cerebral cortex)
The first structures encountered are the autonomic ganglia and nerves.
Then the info passes through one or several neurons of the ANS to the effectors: smooth muscle, cardiac muscle, or glands
Somatic nervous system
comes form the Greek word "soma" - "body"
begins in cerebral and cerebellar cortex (the outer covering which form the bulk of the brains matter)
then passes through axons to the spinal cord or to brainstem centers controlling movement (for the face)
contact between nerve cells relay (synapes) information to another set of neurons call alpha motor neurons.
it is these motor neurons which make contact with skeletal muscle at the neuromuscular junction
synapses
contact between nerve cells
relay information to another set of neurons call alpha motor neurons
In practice, we use the terms somatic motor system, _______ _______, and _______ _____ more or less interchangeably.
voluntary muscle, Skeletal muscle
The Central nervous system (CNS) is comprised of...
... the brain and the spinal cord.
The peripheral nervous system (PNS) is comprised of the ...
Cranial nerves III-XII
Spinal nerves
ganglia
enteric plexi
sensory receptors
Ganglion (pl. ganglia)
A collection of nerve cells in the PNS
Nucleus
a collection of nerve cells in the CNS
(note that this is confusing: we are talking about a nucleus as a collection of nerve cells, each of which has its own nucleus, cytoplasm and cell membrane
Also one CNS structure is called the basal ganglia, which is why many neuroscientists are trying to change the name to basal nuclei
Some scientists include the _______ ______ ______, which controls the motility and functions of the digestive organs, as a separate division, while others group it with the __________ _________ ________.
enteric nervous system, autonomic nervous system
Plexus (pl. plexuses or plexi)
a network of neurons located in the walls of digestive organs.
