Topic 5 Flashcards
The nervous system maintains internal order within the body by coordinating the activities of muscles and organs. Comprising the central nervous system (CNS) and the peripheral nervous system (PNS), the mamalian nervous system receives input from sense organs which in turn generates output in the form of various responses and reactions within the body.
What are basic functions of the nervous system?
To sense changes (sensory), to interpret these changes (integrative), and to react to changes (motor)
Name the three distinct portions of the neuron.`
Cell body, dendites and axon.
What is axon covered with and what is their purpose?
Covered in myelin sheath. This increase the speed of impulses and to insulate and maintain the axon.
There are six types if nuroglial cells. What are these types of glial cells?
Astrocytes Oligodendrocytes Microglia Ependymal cells Schwann cells Satellite cells.
What is Nodes of Ranvier?
Gaps in the myelin. They are important for signal conduction.
What is white and grey matter?
White matter is axons that are myelinated.
Grey matter is cell bodies, dendrites, unmyelinated axons, axon termicals, neuroglia.
The brain cortex is made up of what matters?
Grey and white.
What is a resting membrane pontential?
It is when the membreane of a non conducting neuron is posively charged outside and negatively inside.
When does the inside of the neuron become positively charged?
When a threshold stimulus is presented.
What is the refractory period?
It is a short break when action potential has occured
Do larger nerve fibres conduct impulses faster?
Yes
Saltatory conduction only occurs in the presence of what?
Nodes of Ranvier
What is the junction between neurons called?
Synapse
How are neurotransmitters removed?
Diffusion, enzymatic degradation, re-uptake
What are the major areas of the brain?
Medulla Cerebrum Diencephalon Cerebellum Midbrain Pons Medulla
What is the purpose of the brain blood barrier?
Protects the brain from harmful substances by controlling the passage of certain materials from blood to the brain.
What fluid protects the brain and CNS againts chemical and physical injury?
Cerebrospinal fluid.
What is the function of the medulla oblongata?
Acts as reflex centres for the regulation of heart rate, respiratory rate, sneezing, coughing etc.
Where is pons located and what is the function of it?
Above the medulla and it relays nerve impulses related to voluntary skeletal movements from the cerebral cortex to the cerebellum.
What are the major regions of deincephalon?
Thalamus, hypothalamus, pineal gland.
What is the function of the cerebellum?
Coordination of skeletal muscles, regulates posture and balance.
How is the spinal cord protecteed?
Protected by the bony vertebral column, meninges, cerebrospinal fluid, and vertebral ligaments.
What is the major function of the spinal cord?
Convey sensory information.
Which part of the brain coordinates the skeletal muscles?
Cerebellum
Which part of the brain is responsible for involuntary movements?
Brain stem
Which part of the brain controls emotions?
Limbic system.
Where is the limbic system located in the brain?
Between the brain stem and two cerebral hemispheres.
What are the three parts regions makes the brainstem?
Midbrain
Pons
Medulla
What is the function of the midbrain?
Controls muscle coordination and maintain posture.
What does the autonomic nervous system regulate?
Regulates the activities of smooth muscle, cardiac muscle and glands.
Name the 2 subdivisions of the ANS
Sympathetic and Parasympathetic.
Sympathetic and parasympathetic are antagonistic. What does this mean?
They are opposite of each other. If one of them increases specific activity, the other one will function to decrease that activity.
Where is the cell body of the preganglionic neuron located and is it myelinated?
CNS and it is myelinated
Where does the postganglionic neuron lie?
PNS
What is the difference between sympathetic and parasympathetic?
The sympathetic prepares the body for the “fight or flight” respons during any potential danger. Parasympathetic inhibits the body from overworking and restores the body to a calm and composed state.
