Nervous System Flashcards
what does the nervous system consist of
Central Nervous System
Peripheral Nervous System
Central Nervous System
consists of brain and spinal cord
Peripheral Nervous System
consists of Cranial Nerves and Spinal nerves and Ganglia
detects stimuli and transmits information from receptors to the CNS
is Afferent
Sensory nervous system
initiates and transmits information from the CNS to effectors
Is efferent
Motor nervous system
Somatic Sensory
sensory input that is consciously perceived from receptors (eg. eyes, ears and skin)
Sensory nervous System
Visceral Sensory
Sensory input that is not consciously perceived from receptors of blood vessels and internal organs (eg. Heart)
Sensory Nervous System
Somatic Motor
Motor Output that is consciously or voluntarily controlled: effector is skeletal muscle
Motor Nervous System
Autonomic Sensor
Motor output that is not consciously or is involuntarily controlled: effectors are cardiac muscle, smooth muscle and glands
Sympathetic Division
typically speeds up body activities
“fight of flight”
Autonomic motor
Parasympathetic Division
typically slows down body activities (except for digestion)
“rest and digest”
Autonomic Motor
what 2 cell types make up the nervous tissue
Neurons (excitable)
Glial Cells (supportive)
Conduct impulses from one part of the body to another. Have a high metabolic rate. They have extreme longevity and most cease mitosis after fetal development. Excitable to stimulus
Neurons
Neuroplasticity
the ability of your nervous system to remodel itself in response to internal and external factors
Neurogenesis
the development of new neurons, thought to only occur only in specific areas of the CNS and PNS
conduct impulses towards the cell body
Dendrites
conduct impulses away from the cell body
Axons
Glial Cells in the CNS
- Astrocytes (blood brain barrier)
- Epindymal Cells (CSF)
- Microglial Cells (phagocytic)
- Oligodendrocytes (create myelin sheath)
Glial Cells in the PNS
- Satellite Cells (regulate in and out)
- Schwann Cells/neurolemmocytes (myelin sheath)
these envelop the brain capillaries and reduce capillary permeability. This helps create the blood brain barrier. They are also involved in repair and scarring process of brain and spinal cord when injuries occur
Astrocytes
Blood Brain Barrier
a controlled molecule flow to the brain is essential for stable brain function. The blood brain barrier does this
Ependymal Cells
line the internal cavities of the brain and the central canal of the spinal cord. These cells and nearby capillaries from a network called the choroid plexus which produces cerebrospinal fluid
Choroid Plexi
formed by the ependymal cells that line the ventricles and by nearby blood vessels. CSF is essentially a filtrate of plasma
Microglial Cells
wandering phagocytic cells that ingest and remove debris throughout the CNS
Oligodendrocytes
cells that ensheathe portions of axons in the CNS by repeatedly wrapping around an axon to create a myelin sheath
Satellite Cells
flattened cells that arrange around neuronal cell bodies in ganglia of the PNS and help regulate the movement of nutrients and waste products.
Schwann Cells (neurolemmocytes)
responsible for forming myelin sheath around axons in the PNS
nerve
cable-like bundle of parallel axons
convey sensory information to the central nervous system and all axons are conducting impulses in the same direction
Sensory nerve (afferent)
convey motor impulses from the central nervous system to the muscles and glands and all the axons are conducting impulses in the same direction
motor nerves (efferent)
carry both types of information and some axons are transmitting impulses in one direction, while other axons are transmitting impulses in the opposite direction
mixed nerves
neural groove
develops in the embryo during the third week of development
neural tube
has an opening near the future head and an opening near the future buttocks.
by the end of the third week the neural groove comes together and fuses along the midline to form this
