Nervous system Flashcards
What is the function of the nervous system?
controls the coordination of the body’s organs by making homeostatic changes with environmental changes
What two types of cells make up the nervous system?
Neurones
Neuroglia
What do neurones do?
receive, process and transmit electrical information
What do neuroglia do?
speed up electrical signals within neurones
provide nutrients
assist neurone function
regulate communication between neurones
What is the CNS made up of?
brain and spinal column
spinal nerves- in pairs of mixed motor and sensory
cranial nerves- 12 pairs mixed sensory
What is the PNS (peripheral nervous system) made up of?
nerves outside of CNS
What are sensory nerves?
transmit impulses to the brain (afferent)
enter the spinal cord by the dorsal root
cell bodies are in the ganglia outside the spinal cord
What are motor nerves?
leave the spinal cord by the ventral root
transmit impulses from the brain (efferent)
What are the functions of the autonomic nervous system (ANS)?
- controls bodies internal environment in a coordinated manner through a series of complex reflex actions
- automatic control
- Neurotransmitters are released and carry the signal to the next nerve or organ
What does the ANS regulate?
blood pressure heart rate intestinal motility pupil dilation glandular tissue
What is viscera?
smooth muscle, cardiac muscle and some endocrine glands
What is the function of neurotransmitters?
impulses passed between nerves and synapses
transfer of impulses occur due to secretion of neurotransmitter chemicals
What is the semantic neurotransmitter?
Acetylcholine ACh
What are the autonomic transmitters?
Sympathetic neurotransmitter
Noradrenaline involved in fight or flight
Parasympathetic neurotransmitter
Acetylcholine ACh involved in rest and digest
What is the parasympathetic responsible for?
Rest and digest
Normal maintenance
Promotes secretions and mobility of different parts of the digestive tract, urination and defecation
Initiated when appropriate
Vagus nerve is the chief parasympathetic nerve
What is the sympathetic nervous system responsible for?
Fight or flight
Body has sudden burst of energy
Increases cardiac output and pulmonary ventilation
Routes blood to the muscles and raises blood sugar
Slows digestion and kidney filtration
What is the neurone made up of?
- Cell Body- SOMA contains neurofibrils; single nucleus
- Axon- long cylindrical; transmits electrical impulses away from the cell
- Dendrites- receive impulses and transmit info towards the cell body
synaptic terminals- Boutons
basic functional unit
What are Neuroglia?
Supporting cells that.... separate and protect neurone provide supportive framework act as phagocytes regulate interstitial fluid 50% of the volume of the NS
What are the neuroglia found in the CNS and what are their functions?
Astrocytes- blood brain barrier
Oligodendrocyte- forms myelin sheath
Microglia- Phagocytes, remove waste and pathogens
Ependymal- Line central canal and ventricles
What are the neuroglia found in the PNS and what are their functions?
Satellite- surround cell bodies and ganglia neurones
Schwann Cells- forms myelin sheath around axons in the PNS
What is the difference between white and grey matter?
Grey- unmyelinated
-Cerebellar cortex generates instructions on how to correct movements
-Deep cerebellar nuclei relay instructions to other parts of the brain
White- myelinated with oligodendrocytes
-Arbor vitae axons that carry info to and from cerebellar cortex
What is the function of the cerebellum?
receives information from the sensory systems, the spinal cord, and other parts of the brain and then regulates motor movements.
Coordinates voluntary movements such as posture, balance, coordination, and speech, resulting in smooth and balanced muscular activity.
Lesions cause clumsiness
What is the function of the cerebrum?
The cerebrum or cortex is the largest, most complex part of the brain, associated with higher brain function such as thought and action. Many folds (gyre and sulci) to increase surface area
What is the function of the hypothalamus?
controls certain metabolic processes and other activities of the ANS.
It synthesizes and secretes neurohormones, often called hypothalamic-releasing hormones.
homeostasis centre
nerve responses
