Unit 1 (C)- the cells of the nervous system

The 2 main cells of the nervous sytsem.

Neurons and glia cells

Explain the role of the membrane in neurons.

Composed of a phospholipid bilayer that is active and semi- permeable, allowing certain compounds to enter and leave the cell. It contains surface proteins that plays a tole in guidance, recognition, signal transduction.

Name the 2 basic types of surface proteins.

1. Located on the surface of neuron (outer surface)

2. located on the inner membrane surface of neuron

Role of outer surface protein?

During development they form guidance and recognition system

Signal proteins

a type of outer surface protein. when particular molecules bind with the surface proteins, this leads to the transfer of a signal inside the neuron.

Role of inner surface proteins?

• serves to regulate cellular activity

• helps with regulating overall shape of cell which is important for nervous system where the shape of cell has important consequences for its function.

Role of intrinsic protein?

• run all they way through the phospholipid bilayer

• they constitute membrane channels. These membrane channels are often regulated actively.

• they consume energy

• capable of opening/closing under the influence of certain kinds of triggers

• they sometimes include biochemical devices that actively carry substances across membrane.

Define the function of the nucleus in a neuron.

• the control centre for the cell

• DNA is housed here, serves as a template for the construction of proteins

Define the function of ribosomes in a neuron.

Ribosomes are responsible for the construction of proteins, using instructions contained in DNA from the nucleus, with the assistance of RNA.

How do mitochondria contribute to neuronal function?

• powerhouse of the cell

• releases energy from chemical bonds in a substance called ATP, which is essential for cellular activities.

Role of rough endoplasmic reticulum?

• site of construction of proteins that are destined for use outside of cell

• proteins used inside the cell are constructed at free ribosomes

Role of smooth endoplasmic reticulum?

• serves as transport mechanism for moving compounds around inside the cell

• also site for synthesis of fats

what is the role of golgi apparatus in neurons?

critical for the constructions of vesicles that contain neurotransmitters, which are essential for communication between neurons.

role of lysosomes in neurons?

act like “scavengers” that serve to pick up and break down into waste, products, and unwanted substances within the neuron (or cellular debris in cells)

Explain the significance of the myelin sheath in neurons.

fatty material that covers the axons of certain neurons, increasing the speed of spignal conduction along the axon.

describe the structure and function of dendrites in neurons.

dendrites are structures that receive neurotransmitters from other neurons, playing a crucial role in transmitting signals to the neuron.

what is the axon hillock and its importance in neuronal signaling?

The axon hillock is the most proximal region of the axon that must reach a critical threshold for an action potential to occur, making it essential for signal transmission.

how do neurons change throughout an organism’s life?

neurons can change their structure throughout an organism’s life, particularly dendrites, which may adapt based on use, potentially serving as a mechanism for learning.

explain the concept of neurogenesis.

process through which certain brain neurons continue to be created throughout an individual’s lifespan.

describe the transport mechanisms in neurons.

transport mechanism in neuron, carried out by microtubules, serve to transport substances up and down the axon, especially between the cell body and axon terminals.

define the term ‘soma’ in context of neuron structure.

the soma refers to the cell body of the neuron, which contains the nucleus and is essential for the neuron’s overall function.

how does the shape of a neuron relate to its function?

the shape and size of a neuron are critically related to its function; smaller neurons facilitate communication in compacts brain regions, while longer neurons are necessary for controlling distant body parts.

what is the synapse and its roles in neuronal communication?

the synapse is the tiny region between the axon button of one neuron and the dendrite of another, where neurotransmitters are released to facilitate communication between neurons.

explain the concept of Node of Ranvier?

The node of Ranvier is a tiny gap between segments of myelin on an axon, allowing ions to pass in and out of the axon, which is important for signal conduction.

describe the differences between gray and white matter in brain.

• Gray matter consists of neuron cell bodies and dendritic processes

• white matter is mostly composed of myelin-covered axons

what happens to neurons after brain injuries?

most brain injuries result in permanent brain damage, as while some parts of neurons can regrown, damaged neurons care often not replaced.

Explain the roles of pre-synaptic and post-synaptic membranes in neuron communications.

• the pre-synaptic membrane is the portion of the axon button that releases neurotransmitters into the synapse

• post-synaptic membrane is the portion of the dendrite that receives these neurotransmitters.

what are the 3 basic types of neurons based on their shape?

1. unipolar

2. bipolar

3. multipolar

do unipolar neurons have specific function? if so, describe it.

yes, unipolar neurons typically function as sensory neurons, bringing information abt touch from skin to the spinal cord and eventually to the cerebral cortex.

bipolar neurons

common in the retina

explain the significance of multipolar neurons in the nervous system.

multipolar neurons are the most common type in the nervous system, with the bulk of neuron in the cerebral cortex being multipolar.

what are stellate cells and how do they relate to multipolar neurons?

stellate cells are a common types of multipolar neuron characterized by their star-shaped bodies.

describe the role of glia in the nervous system.

glia support the survival of neurons and are crucial for providing them with oxygen and glucose, as neurons don’t directly communicate with blood vessels.

how do the number of glia cells compare to neurons in the nervous system?

glia outnumber neurons in the nervous system by abt 10-100 to 1.

what are the different types of glia and their function?

• Astroglia regulate the blood-brain barrier

• Microglia act as scavengers for cellular debris

• Oligodendrocytes/Schwann cells insulate neuronal axons with myelin.

explain the importance of oligodendrocytes in the central nervous system (CNS)

oligodendrocytes are crucial for insulating neuronal axons with myelin, which is essential for proper neuron function.

what is Multiple Sclerosis (MS) and how does it affect neurons?

MS is a disease that causes demyelination, destroying myelin sheaths while leaving neurons intact, leading to loss of motor control and speech.

Describe the electrical properties of glia beyond insulation.

glia have significant electrical properties and can conduct electrical activity in adition to their insulating functions.