4.8 - Anatomy & Function of the Brain (Synapse included)

Question 1

What are the 3 parts to the brain stem?
What do they do?

Answer 1

1) Medula Oblongata: connects spinal cord to the cerebellum and deals with autonomic nerve control
2) Pons: transfers nerve signals between cerebellum and medula oblongata
3) Midbrain: carries out higher level functions

Question 2

What is the cerebellum?

Brain

Answer 2

It deals with muscle movement and balance

Question 3

What is the corpus collosum?

Answer 3

It connects the 2 hemispheres of the brain, as well as coordinates their functions

Question 4

What is the homunculus?

Answer 4

• It’s a map of the somatosensory strip (sensory area) and motor strip (motor area).
• for the sensory portion: it maps out where afferent connections lead from into the brain
• for the motor portion: it maps out where efferent connects lead out of the brain

Question 5

What is grey matter?

Answer 5

It is made up of cell bodies with NO myelin. Usually where info is processed

Question 6

What is white matter?

Answer 6

It is made up of mostly axons and transmits signals. It is considered “white” b/c it’s insulated by myelin

Question 7

What are three examples of neuro-toxins?

Answer 7

• tetrodotoxin
• botox
• tetanus (like the needle/shot)

Question 8

What is the synaptic cleft?

Answer 8

• It’s a tiny gap between the presynaptic and postsynaptic neurons (in between 2 neurons)
• neurotransmitters diffuse around here

Question 9

What connects a chain of neurons and allows for it to transmit signals over a distance WITHOUT direct contact?

Answer 9

Synaptic connections
(aka the synapse)

Question 10

Briefly discribe how the synapse is used to send a signal.

Answer 10

• a transmitting neuron releases a chemical known as neurotransmitter
• that diffuses across the synapse and binds to the receptors on the next/receving neuron
• neurotransmitters fuse with the membrane, and dump the transmitter into the synapse
• the binding causes the neuron to activate and pass on the signal
• common neurotransmitters are serotonine & dopamine

Question 11

Briefly discribe how the synapse clears a signal.

Answer 11

• Esterasers are enzymes that remove and break down neurotransmitters
• the NTs can be pumped back into the neuron and recycled

Question 12

Where are neurotransmitters stored?

Answer 12

They are kept in vessicles within the terminal branches of a neuron

Question 13

True or False:

Neurotransmitters are only activators

Answer 13

False.
Neurotransmitters can be activators but also inhibitors, which can be used to shut down some connections (ex. some narcotics, insect & snake posion, etrodoxin, tetanus, botox)