the nervous system Flashcards
1
Q
what are the functions of the nervous system?
A
- collect information: monitor external and internal changes (sensory input from PNS)
- process and evaluate information: processes sensory input and determines response
- response to information: dictates response by activating effector organs
1
Q
what makes up the nervous system?
A
neural tissues (neurons + glial cells)
2
Q
what is the sensory nervous system?
A
- contains receptors
- transmits information from receptors to CNS
3
Q
what is the motor nervous system?
A
- transfers information from the CNS to the rest of the body
- sends motor information to effectors
4
Q
what is the somatic sensory system?
A
- receives sensory information from skin, fascia, joints, skeletal muscles, and special senses
- free nerve endings in almost every body tissue
- includes receptors for touch, pain, pressure, vibration, and temperature
- also has proprioception (sense of body in space) in skin, body wall, and limbs
5
Q
what is the visceral sensory system?
A
- sensations from the organs (digestive and urinary tracts, reproductive organs, etc.)
- only senses stretch and temperature
6
Q
what is the somatic motor system?
A
- “voluntary nervous system”
- innervates skeletal muscles
- AKA voluntary nervous system
7
Q
what is the autonomic motor system?
A
- “involuntary” nervous system
- innervates cardiac + smooth muscles, and glands
- have no control
- subdivides into the sympathetic and parasympathetic systems
8
Q
what is nervous tissue?
A
- 2 types of cells: neurons + glia
- neurons transmit electrical signals (excitable)
- glia “nerve glue” are supporting cells (not excitable)
9
Q
describe the structure of a neuron
A
- dendrites: receive signals, transmits to cell body. dendrites are smaller projections from the soma
- soma (cell body): contains nucleus, cytoplasm, orgnalles
- axon (long cell process): transmits signal to axon terminals (note direction of signal movement)
- myelin sheath insulates axon, helps propogate signal
10
Q
what role to dendrites and axons?
A
signal pathway:
dendrite —> cell body —> axon —> axon terminal (end of axon)
the more dendrites a neuron has, the more impulses a neuron can receive from other neurons
11
Q
what is a synapse?
A
- the site where an axon connects with another cell (eith neuron, muscle, or gland cell)
- 2 types:
+ chemical synapse (most numerous, use neurotransmitters)
+ electrical synapse rely on flow of ions at gap junctions
12
Q
what are the 4 types of CNS glia?
A
- ependymal cells: helps produce CSF
- microglia: defense
- oligodendrocytes: mylienates axons
- astrocytes: most common, blood-brain barrier
13
Q
what is a nerve?
A
- defined as a collection of axon in the PNS
- the axons are arranged in parallel and wrapped in connective tissue
- a nerve can contain myelinated and/or non-myelinated, and sensory and/or motor axons
14
Q
what is the structure of a nerve?
A
- each axon is surrounded by myelin sheath (schwann cells)
- groups of axons are nerve fasicles
- groups of fasicles = nerves
