1- Introduction to the Nervous System Flashcards
State some of the functions of the nervous
- To detect changes in both the external and internal environment
- To receive sensory input
- To relay information and analyse it
- To initiate appropriate responses
What are neurones?
They are the most basic unit of the nervous system
They are cells
What is the role of neurones?
To convey information via electrical signals
It receives, integrates and transmits electrical information
What are the 3 main types of neurones?
- Afferent/sensory
- Efferent/ Motor
- Interneurones
Describe afferent neurones
They carry electrical information from the receptors to the CNS
(Brings input to the CNS)
Describe efferent neurones
They carry electrical information from the CNS to the peripheral effectors
Describe interneurones
Found only in the CNS
They link the afferent neurones with the efferent ones
Describe the cell body of neurones
Inside the cell body there is a nucleus which all the cells organs
What makes neurones different to other cells?
- They have dendrites
2. It has an Axon
Describe dendrites
They are projections fro the cell body that receive information
Describe axons
It is in-charge of sending information the cell body receives to the other neurones
What is a synapse
This is where neurone 1 meets neurone 2
It is where 2 neurones communicate
What is the neurone before the synapse called?
Pre synaptic cells
What is the post synaptic cell
The neurone after the synapse
What happens at the synapse?
Neurotransmitters are released from the presynaptic neurone
These neurotransmitters are picked up by the post synaptic neurone
What are neurotransmitters?
Chemical messengers that send electrical signals to the post synaptic neurone
What is the Nervous system split into?
- The central nervous system
2. The peripheral nervous system
What is the CNS made up of?
Only the brain and spinal cord
What can the peripheral nervous system be slit into?
- The somatic nervous system
2. The autonomic nervous system
What does the somatic nervous system control?
It controls the external actions of skin and muscle
What does the autonomic nervous system control?
It controls internal activities of the organs and glands
What can the autonomic nervous system be further split into?
- The sympathetic nervous system
2. The parasympathetic nervous system
Define the term anterior
Anything towards the front of the body
Define the term ventral
Anything towards the front of the body
Define the term posterior
Anything towards the back of the body
Define the term dorsal
Anything towards the back of the body
Define the term rostral
Towards the head (Above)
Synonymous with superior
Define the term caudal
Towards the feet/ tail (below)
Synonymous with inferior
What is the coronal plane?
An imaginary plane dividing the body into dorsal (posterior) and ventral (Anterior) parts
What is the sagittal plane?
An imaginary plane dividing the body into left and right sides
What is the transverse plane?
An imaginary dividing line that separates the superior and inferior sections of the body
What does the CNS develop from?
A neurone tube that develops a bend at the superior rostral part of the head
In the brain what is dorsal synonymous with after the bend forms?
Superior
In the brain what is ventral synonymous with after the bend forms?
Inferior
In the brain what is posterior synonymous with after the bend forms?
Caudal
In the brain what is rostral synonymous with after the bend forms?
Anterior
Describe the cerebrum in the brain
The cerebrum is a large part of the brain containing the cerebral cortex as well as several subcortical structures
What are some of the sub divisions of the CNS?
- The cerebrum
- The brain stem
- The cerebellum
- The spinal cord
What can the cerebrum be divided into?
The outer brain (Telencephalon)
The inner brain (Diencephalon)
What can the outer brain also be called?
Telencephalon
What can the inner brain also be called?
Diencephalon
What can the brainstem be further divided into
The midbrain (top portion) Pons (middle brown portion) Medulla oblongata (inferior part)
What is the role of the brain stem?
Links our brain to the spinal cord
What is the medulla oblongata directly connected to?
The spinal cord
Describe the cerebellum
Is translates to the ‘small brain’
It is found at the back below the cerebrum
Describe how the CNS forms in the embryo
As a hollow straight tube
It forms 3 swellings and a bend at the rostral end
What are the 3 swellings that develop in the hollow tube in utero responsible for?
They are responsible for developing into the different parts of the brain
What are the 3 swellings that develop in the hollow tube in utero called?
- The forebrain (Prosencephalon)
- The midbrain (Mesencephalon)
- The hindbrain (Rhombencephalon)
What is another name for the forebrain?
Prosencephalon
What is another name for the midbrain?
Mesencephalon
What is another name for the hindbrain?
Rhombencephalon
Anything at the caudal end of the tube develops to form what?
The spinal cord
What does the central canal develop into?
It remains and develops into expansion fluid
What happens once the first 3 swellings have formed in the embryo?
These 3 swellings become 5 swellings
What are the 5 new swellings that form after the first 3 swellings called?
- Telencephalon
- Diencephalon
- Mesencephalon
- Metencephalon
- Myelencephalon
What does the Prosencephalon (forebrain) swelling turn into?
Telencephalon
Diencephalon
What does the diencephalon give rise to?
Our optic vessels
What does the Mesencephalon (middle brain) swelling turn into?
Stays the same
What does the Rhombencephalon (hind brain) swelling turn into?
Metencephalon
Myelencephalon
What does the telencephalon give rise to in the mature brain?
The cerebral hemisphere
What does the Diencephalon give rise to in the mature brain?
The Diencephalon
ie the thalamus and hypothalamus ect
What does the Mesencephalon give rise to in the mature brain?
The midbrain
What does the Metencephalon give rise to in the mature brain?
The pons
The cerebellum
What does the Myelencephalon give rise to in the mature brain?
The medulla oblongata