Lecture: Nervous system

what does a neuron do?

A neuron transmits electrical signals throughout the nervous system, allowing communication between the brain and other body parts. It processes and relays information through synapses.

What are impulses?

Impulses are electrical signals that travel along neurons, facilitating communication within the nervous system and enabling reactions to stimuli.

what part of the neuron do axons travel down?

axon

Fill in the blank

Dendrites are extension that ___ information. While axons ___ information.

receive; send

Where are the living parts of the neuron?

cell body and soma

where is the axon hillock located?

The axon hillock is located at the junction between the cell body and the axon of a neuron, serving as the site where action potentials are initiated. It looks like a cone

where are action potentials fired from in the neuron?

Action potentials are fired from the axon hillock, which acts as the initiation point for these electrical signals.

what are myelin sheaths?

Myelin sheaths are insulating layers formed by oligodendrocytes in the central nervous system and Schwann cells in the peripheral nervous system, which wrap around the axons of neurons. They enhance the speed of electrical signal transmission along the axon.

what is the name of the gaps in the myelin sheaths?

The gaps in the myelin sheaths are called nodes of Ranvier, which facilitate saltatory conduction of action potentials along the axon.

what do myelin sheaths do to the speed of an electrical signal?

Myelin sheaths increase the speed of electrical signal transmission by preventing ion leakage and allowing action potentials to jump between nodes of Ranvier.

read

Whit matters is associated w/ the CNS, myelinated sheaths of axon, and nodes of ranvier

Read

Grey matter is associated w/ unmyelinated axons in the CNS

What is a multipolar neuron?

A multipolar neuron is a type of neuron characterized by multiple dendrites and a single axon,

what is sensory neurons function?

send signals fron the environment to the cns

What kind of neurons are known as sensory neurons?

afferent neurons

where are interneurons located? what is their function?

Interneurons are primarily located in the central nervous system, and their function is to process information between sensory and motor neurons, facilitating communication and reflexes.

Fill in the blank

motor neurons are also known as ___ neurons. They conducts impulses from the brain and spinal cord to the muscles

efferent neurons

what type of neurons help with locomotion?

Motor neurons are responsible for locomotion, sending signals to muscles to enable movement.

describe the patellar reflex

The patellar reflex is a knee-jerk reaction initiated by tapping the patellar tendon, which stretches the quadriceps muscle and triggers an involuntary contraction, causing the leg to kick.

what neurons are involved in a reflex

Sesory nueron —> interneurons —> motor nuerons

what are microglial cells

The immune system of the brain and prevent infection

Fill in the blank

The myelin sheaths of the CNS is called _____

oligodendrocytes.

Fill in the blank

The myelin sheaths of the PNS is called _____

Schwann cells.

what are the two major organs that constitute the CNS

The two major organs that constitute the CNS are the brain and the spinal cord.

What are astrocytes?

Astrocytes are star-shaped glial cells in the central nervous system that provide support e.g. nutrients

Fil in the blank

____ serve as blood brain barrier

astorytes

What do you call neurons before and synapse and after

The neurons before a synapse are called presynaptic neurons, while those after the synapse are referred to as postsynaptic neurons.

Fill in the blank

When an impulse gets the end of a neuron @ the synapse ___ are released

neurotransmitters

What releases neurotransmitters?

Presynaptic neurons release neurotransmitters into the synaptic cleft and effect th

what the neurotransmitter oxytocin do?

make you feel love

what the neurotransmitter serotonin do?

make you feel happy

what the neurotransmitter dopamine do?

reward, pleasure.

what does adrenalin do?

It increases heart rate and energy.

what do endorphins do?

euphoria

cocaine will cause a rellease of what

Dopamine

heroin will cause a release of what

euphoria and a sense of well-being.

caffeiene will cause a release of what

dopamine and adrenaline.

nicotine will cause a release of what

dopamine

ecstasy will cause a release of what

serotonin

what drug acuses you to become addicted in onw hit?

methamphetimes

what is the membrane potential @ rest?

-70mv

At what charge is there an action potential charge?

-55mv

The pns is composed of?

all the nerves outside the brain and spinal cord, including sensory and motor fibers.