Introduction to the Brain Flashcards
What is a neurone?
What are the basic functions of a neurone?
The most basic functional unit of the nervous system
they convey information via electrical signals
they receive information, integrate it and transmit it to other neurones
What is meant by an afferent neurone?
Sensory neurone
this carries information from receptors TOWARDS the CNS
What is meant by an efferent neurone?
Motor neurone
this carries information AWAY from the CNS, towards the peripheral effectors
What is meant by an interneurone?
This is a smaller neurone that links afferent neurones with efferent neurones within the CNS
They are only found within the CNS
What is the difference between a presynaptic and postsynaptic neurone?
Presynaptic:
- releases neurotransmitters as a result of an action potential travelling down the axon
- the neurone before the synapse
Postsynaptic:
- receives the neurotransmitter and the message
What are the roles of the dendrites?
They receive stimulation from other neurones, in order for the cell to become active
They conduct messages to the neurone cell body, allowing it to function
What is the role of the myelin sheath?
Myelin sheath allows electrical impulses to transmit quickly and efficiently along the nerve cells
What are the 3 different types of neurones?
- Bipolar
- Pseudo-unipolar
- Multipolar
What is meant by a bipolar neurone?
Where are they found?
It has only 2 processes extending from the cell body - an axon and a dendrite
Many are specialised sensory neurones for the transmission of sense
e.g. Proprioception, light, touch, hearing
What is a pseudo-unipolar neurone?
Where do they tend to be found?
It has only one extension from the cell body
The axon then splits into 2 branches - one travels to the CNS and one to the PNS
They tend to be sensory neurones and information is able to bypass the cell body
What is meant by a multipolar neurone?
Where do they tend to be found?
It has a single axon and multiple dendrites
This allows for a great deal of integration from other neurones
Tend to be motor neurones
What are the subdivisions of the nervous system?
It is divided into the central and peripheral nervous systems
Peripheral NS is divided into the somatic and autonomic nervous systems
Autonomic is divided into the sympathetic and parasympathetic nervous systems
What is the difference between the somatic and autonomic nervous systems?
Somatic:
- controls external actions of skin and muscles
- responsible for things we are conscious of feeling e.g. motor control
Autonomic:
- controls internal activities of organs and glands
- responsible for actions we are unaware are happening
What is the difference between the sympathetic and parasympathetic nervous systems?
Sympathetic:
- arousing - “fight or flight”
Parasympathetic:
- calming - “rest and digest”
Label the following directions when it comes to the brain
Ventral = towards the abdomen
Rostral = towards the face
Caudal = towards the tail
Dorsal = towards the back of the body
What are the two parts of the cerebrum (forebrain)?
- Telencephalon (outer brain or cerebral hemisphere)
- diencephalon (inner brain)
What components make up the brainstem?
- Midbrain
- Pons
- Medulla oblongata
How is the cerebrum divided?
It is divided into a right and left cerebral hemisphere
these are separated by the longitudinal fissure
What is the surface of the cerebrum marked by?
Elevated ridges (Gyri) and grooves (sulci)
What is meant by the corpus callosum?
It connects the right and left hemispheres and acts as a passageway for information to travel between them
Label the following Sagittal section of the brain
What is meant by a “ventricle” of the brain?
An expanded area in the brain that is filled with cerebrospinal fluid
they are located within the brain parenchyma
Why are the pons and cerebellum sometimes considered as the same structure?
They develop from the same embryonic tissue and share many functions
What is the purpose of the sulci and gyri?
The surface of the cerebral hemispheres are heavily folded to increase surface area
