The Nervous System Flashcards
1- identify the two major subdivisions of the NS
Peripheral NS- extremities of the body
Central NS- centre of the body
1- what are the two major divisions of the peripheral NS?
Autonomic- self regulated actions of internal organs and glands
Somatic- voluntary actions
1- identify the two divisions of the autonomic NS
Sympathetic- arousing
Parasympathetic- calming
1- identify the two divisions of the somatic NS
Sensory input
Motor output (controls skeletal muscles)
1- what is the CNS comprised of?
Composed of- Brain and spinal cord
Contains- relay neurones (interneurons)
1- what is the PNS comprised of?
Composed of- cranial nerves, spinal nerves, peripheral nerves
Contains- sensory neurones, motor neurons
1- what is a neurone?
The basic functional unit of the NS
The NS has over 100 billion neurones in it
1- name as many structures of the neuron as you can
Dendrites
Nucleus
Axon
Axon terminal
Myelin sheath
Cell membrane
Cell body
Axon hillock
Ogliodendrocyte
Nodes of Ranvier
1- what are neuroglia?
The supporting cells of the NS
1- what is an Ogliodendrocyte?
A type of neuroglia
Main job is to support and insulate myelin on axons in the CNS
1- name the three other types of neuroglia and their functions
Astrocytes- help to form the blood-brain barrier
Microglia- remove bacteria and damaged tissue
Ependymal cells- secrete CSF
1- how do you differentiate between neurones in the PNS and the CNS?
PNS neurones- are myelinated by Schwann cells
CNS neurones- are myelinated by Ogliodendrocytes
2- outline the functions of the brain stem
The brain stem is the stalklike part of the brain that connects it to the spinal cord. It is part if the CNS
Overall function- regulates some bodily functions and sends messages between brain and the body
Functions of the brain stem:
It coordinates messages that regulate…
-balance
-blood pressure
-breathing
-facial sensations
-hearing
-swallowing
-heart rhythms
3- what are the meninges of the brain and spinal cord?
Three layers of membrane that protect the brain and spinal cord
Meninges separate them from their bing casing
3- name and describe the three meninges of the Brian and spinal cord
Pia mater-
Delicate inner matter
Highly vascular membrane that closely follows brain contours
Function is to physically separate neural tissue from blood vessels
Arachnoid-
Middle layer
Web-like structure filled with CSF that cushions the brain
All cerebral arteries and veins are located here
Dura mater-
Tough outer layer
Made of dense connective tissue
4- identify the origin of CSF, how is it made?
It is formed in the cerebrospinal ventricles
Ependymal cells create CSF, it is then secreted by the choroid plexus
It is constantly secreted, so is completely renewed 5 times in a day
4- what functions does CSF perform?
It has 5 main functions:
1- Support
Supports the weight of the brain and keeps it buoyant
2- Shock Absorber
Protects the brain from damage and head trauma
3- Homeostasis
Electrolytes maintain osmotic pressure
Maintains a stable temp
Waste products removed
4- Nutrition
Glucose, protein and lipids
5- Immune Function
Contains immunoglobulins