2. Brain cells Flashcards
What is the cell body?
contains nucleus and major organelles
What is the cytoplasm?
Contains nissi granules, proteins, neurofilaments and neurotubules
What are dendrites?
Receive info from other neurons between different neurons
What is the axon?
Where the nerve impulse travels down
What is the axon hillock?
Where the cell body tapers
What is the myelin sheath?
insulation and prevents the impulse leaving the axon, improves conduction
What are the nodes of ranvier?
Allow nerve impulses down, jumping conduction, important in action potential
What is the axon terminal?
where info is transmitted from one cell to the next
What is the axodentric junction?
Where two neurons meet
What is morphology?
A way of classifying neurons based on the number of neuronal processes (bits that stick out of the cell)
Where are Unipolar neurons found?
In invertebrates
How many branches does a Unipolar neuron have?
two axonal branches- one to the periphery, other to spinal cord
What type of neurons are unipolar?
sensory neurons
What does a bipolar neuron mean?
One axon, one dendrite
What does a multipolar neuron mean?
Several dendrites, one axon
What are the two classifications of Multipolar neurons based on length?
Golgi 1- long axons
Golgi 11- short axons
How are neurons important in sensation?
They signal danger or pain by sending info from the senses
How are neurons important in integration?
They help us process all the info gathered and take action
How are neurons important in action?
They send appropriate signals to affectors (muscles and glands) and the withdrawal reflex (evolutionary)
What are the three kinds of functional classification for neurons?
Toward, within or away from the CNS
What neurons are towards the CNS?
sensory or afferent neurons
What neurons are within the CNS?
interneurons or multipolar neurons
What neurons are away from the CNS?
motor neurons or efferent neurons
What is the endoplasmic reticulum found in eukaryotic cells?
A membrane enclosed passageway for transporting materials
What is the golgi apparatus?
It receives vesicles of proteins which are transformed into forms the cell can use by folding them into usable shapes or adding other materials
What is the resting membrane potential?
The electrical charge across the cell membrane- neurons are polarised at rest
What does the membrane do to maintain polarisation in the neuron?
It controls the environment within and around the neuron
How does being selectively permeable control polarisation?
It allows some things in and not others
What is the membrane partly a result of?
A balance between two opposing forces
What is diffusion?
Molecules distributing themselves evenly through the medium in which they are dissolved
What is electrostatic pressure?
A force exerted by attraction or repulsion between charged molecules
What is the membrane?
Barrier that provides cell integrity
What is the lipid billayer?
Allows for selective permeability
What do molecules in the membrane decide?
The selectivity of its permeability
What do proteins in the membrane provide?
Transport
What are two examples of two protein channels in the membrane?
Potassium leak channel (passive)
Ion pumps (active channel)
What does cholesterol provide in the membrane?
Rigidity
What does the Sodium-potassium pump do?
Maintains balance and is an active channel using energy whilst we are at rest
What are Glial cells?
They provide support and protection to neurons
How do glial cells help in supporting neuron mobility?
Support migration and communication of information
How do glial cells physically support neurons?
Provide nutrition
How do glial cells help in neuron cleaning?
They clear waste and contribute to ‘pruning’
What are astrocyte glial cells function?
Nourishment, support and guidance, clean and protect
May have a role in intelligence
What are oligodendrocyte and Schwann glial cells function?
Provide mylein to insulate and speed up process of electrical signalling
What is the function of microglia?
Main form of immune defense and synaptic pruning
Could play a role in alzheimer’s
