Nervous System, Brain Overview & Brain Protection Flashcards
What are Nerves?
Collection of cells (neurons) which provide anatomical links to the tissues and the brain and vice versa
What are the 2 Types of Neurones going to and from the Tissues?
Afferent - towards brain and Efferent - away from brain
2 Parts of the NS and what Nerves do they Split into?
- CNS (brain and spinal cord)
- Peripheral NS (everything else) these divide into spinal and cranial nerves
What does the Peripheral Nervous System Split into?
Somatic NS and the Autonomic NS
What are the Somatic NS and Autonomic NS responsible for?
Somatic - Controls skeletal muscle (conscious control)
Autonomic - Controls visceral (smooth) muscle, cardiac muscle, glands (unconscious control)
What does the Autonomic System Split into and what does it correspond to?
Sympathetic NS - fight/flight/freeze (speed up)
Parasympathetic NS - rest/digest/feed/breed (slow down)
In Terms of NT’s how is Addiction Initiated?
- Synapses become overstimulated which damages neurones
- This causes a failsafe to kick in which reduces the effect of NT’s
- This reduces the threshold of how much NT it takes to reach a certain level of feeling. Tolerance has increased.
In terms of Stress how is Addiction Formed?
- During stress, the hormone cortisol
- Cortisol acts upon the pre-frontal cortex to help you manage situations
- During chronic stress, the brain seeks for stress relievers
- This increases dopamine release driving you to seek stress relief more and more
- Cortisol also dampens the effect of serotonin, so we concentrate on the thing that’s stressful more
- AAR dopamine leads you to seek reward while reduced serotonin means you won’t feel satisfied
Common NT’s (acetylcholine, dopamine, glutamine, serotonin)
Acetylcholine - Initiates movement to muscle fibres. Facilitates neuroplasticity (ability to change, modify and adapt across the cortex
Dopamine - Pleasure chemical that seeks for rewards and nice things eg adrenaline seeking
Glutamine - Excitement chemical, linked to memory and learning
Serotonin - Calming chemical that modulates mood and brings sense of satisfaction - deficiency leads to depression
Common NT’s (Norepinephrine, Gama-Aminobutyric Acid, Endorphins)
Norepinephrine - Hormone and NT linked to stress response, arousal, vigilance and memory
Gama-Aminobutyric Acid (GABA) - Inhibits neural signalling. Linked to learning. Too little = seizures
Endorphins - euphoria/wellbeing doing something you enjoy
What are the Brains Different Parts?
- Brain Stem
- Diencephalon
- Cerbrum
- Cerebellum
What are the Different Ventricles of the Brain? And Where are they?
- Lateral Ventricle - (2) in each hemisphere
- Third Ventricle - located in slit between thalamic halves
- Fourth Ventricle - between brain stem/cerebellum
What Connects the two halves of the Brain?
White matter called Corpus Callosum
How does the Blood Brain Barrier Protect the Brain?
- It has a selective barrier to allow nutrients to pass freely, stopping pathogens crossing. Allows hydrophobic (O2, CO2)
- Separates bloodborne substances from neurones
What does the Cerebrospinal Fluid do?
- Similar composition to plasma w/ less protein/different ion concs
- Forms cushion layer supporting CNS organs
- Prevents brain crushing under its own weight
- Absorbs pressure impact to CNS from blows and other trauma
- Nourishes brain/carries chemical signals throughout it
