Neurons/Glial/Blood brain barrier

Reticular Theory: An obsolete theory that the brain is connected to the spinal cord and all the nerves are all connected that the brain sends spirits to move muscles

Camillo Golgi:

Golgi stained neurons which made the neurons all look connected

Santiago Ramon y Cajal:

Found interest in Golgis stain, and invented the double stain which was just staining the tissue twice which allowed for him to look at the neurons more prominently

The neuron Doctorine: Cajal double stained juvenile animals tissues and found that these neurons are not connected and need to send signals to each other

Anatomy and function of Neurons and Glia

Neurons: receive and transmit information to other cells

Dendrites: The short branch extensions on the neuron that Receive information

Cell body (Soma): Spherical part of the neuron that contains the nucleus, ribosomes and mitochondria Processes and integrates information

Axon: Long extension (Like the bridge of the neuron) Carries information from one end of the neuron to the other

Presynaptic terminal: Branches and the end of the neuron Transmits information to other neurons

Myelin Sheath: Insulating material Helps with transmission speed

Nodes of Ranvier: Short regions on the axon that are not insulated with myelin sheath Propagtes(Continues to send) electrical signals

Motor Neurons: Neurons that are used to send motor functions

Sensory Neurons: Specialized in sensing things such as temperature

Afferent Axon: Brings information into the body (Sensory)

Efferent Axon: Brings information out of the body (Motor)

Interneuron/intrinsic neuron: if a cells dendrites and axons are contained in a single structure (Has the shortest axon) 

Action potential: When the neuron fires

Nerve: A bundle of axons 

Types of Glia

Astrocytes: Help synchronize the activity of axons by wrapping around neurons, they are responsible for dilating blood cells which invites more nutrients into the brain in highly active areas 

Microglia: Remove waste from the brain, as well as dead dying or damaged neurons

Oligodendrocytes - Build the myelin sheath in the brain and spinal cord

Schwann -  Builds myelin sheath in areas of the body other then the brain and spinal cord

Radial Glia: Is a long stick that guides the neuron to where it needs to be, depending on what the neuron will do with its specialized function.

Blood brain barrier

Blood brain barrier: A mechanism that surrounds the brain and blocks most chemicals from entering the brain

Why do we need the blood brain barrier: Endothelial cells join so tightly that they can block almost anything from passing through to the brain which helps defend from disease and harmful things.

What happens if a virus crosses the blood brain barrier: The microglia will step in to defend

What viruses do cross the blood brain barrier:

• Chicken pox

• Rabbies 

• HIV

• Covid (Can cross the blood brain barrier in rodents)

• Meningitis

• Syphilis

• Herpes

• West nile virus

These are all viruses that cannot be cured, you have it for life