Intro to the nervous system Flashcards
nervous system
Respond quickly to stimuli but short-lived, using action potentials and neurotransmitters
*wire system
endocrine system
Respond slowly but long lasting, by secreting hormones into the circulatory system that travel to the target tissue
*wireless system
what are the 6 different nervous systems?
- central nervous system (CNS)
- peripheral nervous system (PRN)
- autonomic nervous system (ANS)
- somatic nervous system (SNS)
- sympathetic nervous system
- parasympathetic nervous system
5 & 6 are ANS
CNS`
central nervous system
- brain and spinal cord
- Receives sensory input vis PNS sensory
nerves
- Processes/interprets sensory input
(interneurons)
- Sends response to effectors (muscles, gland)
via motor nerves
PRN
peripheral nervous system
- Cranial and spinal nerves extending from brain and spinal cord
- Connects CNS to entire body
ANS
autonomic nervous system
- Cranial and spinal nerves connecting CNS
to heart, stomach, intestine and gland
- Control unconscious activities
has 2 parts….
SNS
somatic nervous system
- Cranial and spinal nerves connecting CNS to skin and skeletal muscle
- Oversees conscious activities
sympathetic nervous system
- Increases heart rate, bronchiole dilation, blood
glucose, blood to skeletal muscle, bladder - Decreases digestion, pupil size, urinary output
“Fight or flight”
“thoracolumbar”
parasympathetic nervous system
- Decreases heart rate, bronchiole dilation, blood glucose, blood to skeletal muscle, bladder
- Increases digestion, pupil size, urinary output
“Rest and digest”
“craniosacral”
what nervous system is responsible for homeostatsis?
ANS (autonomic nervous system)
sensory nerves vs motor nerves
sensory nerves: carry messages from body to brain
motor nerves: carry messages from brain to body
neurons
- amitotic = do not divide
- do not touch (gap between neurons are called synapse)
- conduct nerve impulses
nerves
- a group of neurons form a nerve
- 3 types of nerves: efferent, afferent, mixed nerves
- found in PNS
- transmits information in various parts of the body
what are the 3 structures of neurons?
- unipolar
- Single process extends from cell body
- outside of brain and spinal cord - bipolar
- 2 processes (1 from each end of cell body)
- ears, eyes, nose - multipolar
- Many processes arising from cell body
- brain and spinal cord
what are the 3 functions of neurons?
- sensory neurons
- interneurons
- motor neurons
sensory neurons
specialized receptor ends that sense stimulus and then carry impulses from the peripheral body parts to the brain or spinal cord. Can be unipolar or bipolar
(afferent)
interneurons
entirely within the brain or spinal cord; direct incoming sensory impulses to appropriate parts for processing & interpreting
multipolar
motor neurons
carry impulses out of the brain or spinal cord to effectors
( muscles, glands) (efferent)
multipolar
glial cells
supporting cells of the nervous system. Make up half of the volume of the vertebrae brain and outnumber neurons
astrocytes
provide support between neurons and capillaries
Microglial cells
CNS phagocytic cell, macrophage like
Oligodendrocytes
CNS, produce myelin sheaths in CNS
Ependymal cells
line cavities in CNS, produce & help circulate CSF
Schwann cells
create the myelin sheaths in PNS
