chapter 3 : Biological basis of behaviour(1) Flashcards
What is the function of the amygdala?
The amygdala is a crucial control centre for, among other things, the experience of fear. It is important for the regulation of fear.
What are the two types of cells in the brain?
The brain consists of two types of cells: neurons and glia.
What are neurons?
Neurons are individual cells in the nervous system that receive, integrate, and transmit information.
What are glial cells?
Glia are cells found throughout the nervous system and they provide various types of support for neurons.
They are much smaller than neurons.
What are the functions of the glial cells?
-Providing nutrition, healing, protection, and physical support for the neurons.
-Some act like cleaners, removing debris from the brain.
-Some act like a miniature Pac Man from a
video game, devouring dead and damaged cells
What are the 3 ways in which glia provides protection?
-They produce Cerebrospinal fluid .(CSF) is a colourless fluid surrounding the brain and spinal cord. It has several functions, including serving to cushion the brain during an impact.
-Second, they form the blood–brain
barrier, which prevents foreign material, including some viruses and drugs, from entering the brain.
-Third, they contribute to the immune system of the brain
What is a synapse?
A synapse is a junction where information is transmitted from one neuron to the next. It is the connection between an axon to the dendrites of another neuron.
What are the 5 common structures of a neuron?
- Cell Membrane
- Cell body or Soma
- Dendrites
- Axon
- Axon terminal
What is the cell membrane and what is it’s role?
A barrier that separates the inside of the cell from the outside.
This barrier, called the cell membrane, has small channels or gates that allow, or prevent, molecules from
entering or leaving the cell.
What is a cell body or soma and what is its function?
- Cell body, also called a soma, which contains the nucleus and acts like a
tiny factory where proteins and neurotransmitters.
2.The cell body is where
information from thousands of other cells is gathered and sorted out.
What are dendrites and what is it’s function?
- Dendrites, which gather
much of the incoming information from other cells.
Dendrites are the structures that branch out from the cell body.
- Their main purpose is to increase the surface area of the neuron so that chemicals, released from thousands of other cells, can influence the activity of the
neuron that the dendrites belong to.
What is axon and what is its function?
Axon is a long, thin fibre that transmits signals away from the soma to other neurons or to muscles or glands.
The axon’s main role is to conduct a brief electrical charge away from the cell body.
What is an axon terminal and what is its function?
- Though only one axon leaves each cell body, this axon can branch and each branch ends in an axon terminal.
2.Axon terminals are where chemicals
are released by the neuron to influence the activity of other neurons
What is a myelin sheath?
In humans, many axons are wrapped in cells with a high concentration of a white, fatty substance called myelin.
The myelin sheath is insulating material, derived from specialized glial cells.
What happens if a myselin sheath deteriotes?
If an axon’s myelin sheath deteriorates, its signals may not be transmitted effectively.
The loss of muscle control resulting from multiple sclerosis is due to a degeneration of myelin sheaths.
What is the purpose of the myelin sheath?
- Prevents the axon from being accidently activated and also provides some protection to the neuron
- It speeds up the transmission of signals that move along axons.
- It is very efficient. Each cell maintains an electric charge across its membrane. Myelinated axons only have to maintain this charge at small gaps in the myelin along the length of the axon.
What are neurotransmitters?
They are chemical messengers.
The activity of neurons can be understood by examining four process, what are they ?
Resting potential, action potential, synaptic transmission and graded potentials.
What is Resting potential?
When the cell is at rest, there is an unequal distribution of some molecules between the outside and inside of the cell.
The resting potential of a neuron is its stable, negative charge when the cell is inactive. This charge is about −70 millivolts.
How does the inside of the cell have a larger concentration of negative ions compared to the outside?
Positively charged ions and negatively charged ions flow back and forth across the cell membrane, but they do not cross at the same rate.
The difference in flow rates leads to a slightly higher concentration of negatively charged ions inside the cell.
How is the resting potential maintained?
To create and maintain the resting potential, two
ions are critical: potassium (K+) and sodium (Na+).
There are small openings in the cell membrane, called gates or channels, which allow potassium to move more easily in and out of the cell.
There are channels for sodium (Na+) as well, but they are usually closed
How is the resting potential created?/ What is the sodium-potassium pump?
To create the resting potential there is an exchange
system that pumps three sodium ions out of the
cell for every two potassium cells it pumps in.
This exchange system is known as the sodium -potassium pump.
What is the purpose of the sodium-potassium pump?
It is responsible for keeping more sodium ions
just outside the cell membrane
Because sodium ions are positively charged, the greater concentration of sodium just outside of the cell membrane means that the inside of the cell has a relatively negative charge—this is critical for maintaining the resting potential.
Why is the resting potential called the resting potential?
- First, the resting potential is maintained when the cell is relatively at rest.
- Second, the uneven distribution of ions represents a potential energy stored in the cell.
