PSYC1101 - BRAIN

What connects the two asymmetric hemispheres together?

Corpus Callosum

What is a road map of brain based on differences in structures of strained brain tissue called?

cytoarchitectonics

What are the specialized nerve cells that send, receive, and process information throughout the body

Neurons

Cells that keep the brain functioning and healthy, provide physical structure

Glial cells

How are the glial cells and neurons connected?

The neurons are hanging off of the glial cells, this aids with the communication between neurons

unique neuronal structure that receive input signals to other neurons

dendrites

Sends "output" signals to other neurons

axons

How do neurons communicate: STEP 1

Neuron is waiting to be used, the fatty cell wall keeps different amounts of ions inside and outside the neuron. Creating a resting potential

How do neurons communicate: STEP 2

excitatory and inhibitory messages from other neurons are sent through the dendrites.

How do neurons communicate: STEP 3

Once there are enough messages to exceed the threshold, a rapid depolarisation is initiated at the AXON HILLOCK, creating a current that moves down the axon (action potential)

How do neurons communicate: STEP 4

the axons are permeable to ions so gradually the action potential is not enough for it to reach the end.

How do neurons communicate: STEP 5

Special glial cells called oligodendrocytes wrap around the axon, creating the MYELIN SHEATH which act as insulation to stop the passing of ions

How do neurons communicate: STEP 6

current finally reaches the end of the axon and the arrival of the action potential at the presynaptic axon terminal triggers the release of neurotransmitters

How do neurons communicate: STEP 7

NEUROTRANSMITTERS enter the synaptic cleft (gap between neurons) and dissipate through the cerebrospinal fluid

How do neurons communicate: STEP 8

2 things could happen:

- Excitatory post-synaptic potential (EPSP) = DEPOLARISES postsynaptic neuron

- Inhibitory post-synaptic potential (PSP) = REPOLARISES postsynaptic neuron

Prefrontal Cortex

Planning, Inhibition (automatic reaction like brushing teeth), Working memory

motor cortex

Primarily for planning movements, (not reflexes), selection of physical movements to accomplish a plan. Supplementary movement

hand and mouth most in use

SOMATOSENSORY CORTEX

processes stimuli, pain, pressure, temperature, Proprioception (what your body is doing)

thumbs and lips

Visual cortex info

map of the world is flipped upside down, the lower part of the brain is representing the upper part of what we see, left is representing the right side and vice versa

Neurons are more dense in the centre of the visual field which is less in periphery - hence how our peripheral view is not completely clear

HINDBRAIN: CEREBELLUM

help to COORDINATE movement, works with motor cortex, muscle memory

HINDBRAIN: Medulla, Pons, Reticular formation

regulates breathing, peeing pooping, sleep + wakefulness, makes sure we are actually alive and functioning.

MIDBRAIN: amygdala, medulla

emotions (fear mainly associated with amygdala)

CEREBRAL CORTEX

tends do inhibit our emotional responses (not letting our emotions take over)

AUTONOMIC NERVOUS SYSTEM

controls involuntary bodily functions that would react to your emotions (heart rate increases as you feel scared/stressed)

Sympathetic Branch

your body's fight or flight system, prepares you to deal with stress, danger etc

PARASYMPATHETIC BRANCH

part of the ANS, helps our body conserve energy and relax/recover

PARASYMPATHETIC REBOUND

after the stimulus (sympathetic has activated), the parasympathetic is the one that helps restore the body to normal.

Dog is running to you, increase heart rate, realises the dog is friendly.

Sympathetic nervous system

consists of two chains of neuron clusters just to the left and right of the spinal cord

Parasympathetic nervous system

sends the message from the brain (medulla) to the spinal cord to the organs.