chapter 11 - nervous system; part 1 Flashcards
what are the functions of the nervous system?
- maintaining homeostasis
- receiving sensory input
- integrating information
- controlling muscles and glands
- establishing and maintaining mental activity
what are the 2 anatomical divisions of the nervous system?
the central nervous system (CNS) and the peripheral nervous system (PNS)
what does the CNS consist of?
the brain and spinal cord
what does the PNS consist of?
sensory receptors, nerves, ganglia, and plexuses
what are the 2 divisions of the PNS?
sensory and motor division
what does the sensory division do?
transmits action potentials to the CNS; usually consist of single neurons that have their cell bodies in ganglia
what does the motor division do?
carries action potentials away from the CNS in cranial and spinal nerves
what are the 2 subdivisions of the motor division?
somatic nervous system and the autonomic nervous system (ANS)
somatic nervous system
skeletal muscles; voluntary control; consists of single neurons where their cell bodies are located within the CNS
autonomic nervous system (ANS)
cardiac muscle, smooth muscle, and glands; two sets of neurons between the CNS and the effector organs; 1st set = cell bodies within the CNS; 2nd set = cell bodies within autonomic ganglia
what are 2 divisions of the ANS?
sympathetic and parasympathetic
sympathetic division
most active during physical activity; fight or flight
parasympathetic division
regulates resting functions; rest or digest
what are the functions of the PNS?
detects stimuli and transmits information to and receives information from the CNS
what are the functions of the CNS?
processes, integrates, stores, and responds to information from the PNS
what do neurons do?
receive stimuli and transmits action potentials
what are the 3 major components of a neuron?
the cell body (soma), dendrites, and axon
cell body (soma)
primary site of protein synthesis
dendrites
short, branched cytoplasmic extensions of the cell body that usually conduct electrical signals toward the cell body
axon
cytoplasmic extension of the cell body that transmits action potentials to other cells
what are the different types of neurons?
multipolar, bipolar, pseudo-unipolar, and anaxonic neurons
multipolar neurons
several dendrites and a single axon; interneurons and motor neurons are multipolar
bipolar neurons
single axon and dendrite and are components of sensory organs
pseudo-unipolar neurons
single axon; most sensory neurons are pseudo-unipolar
anaxonic neurons
no axons, only dendrites; found in brain and retina where they only communicate using graded potentials
