Neuroscience Flashcards
What are the two major divisions of the nervous system?
- central nervous system
2. peripheral nervous system
What is the CNS made up of?
brain and spinal cord
What is the PNS made up of?
– sensory nerves
– motor nerves
– autonomic nervous system
– enteric nervous system
What are the sensory nerves?
Input to CNS from sensory organs (eye ear, vestibular apparatus, nose, tongue, skin)
What are the motor nerves?
Output from CNS to muscles.
What is the autonomic nervous system?
– controls many non-voluntary bodily functions, e.g. digestion, heart rate blood pressure, sweating, pupil size, genitals (4Fs – feed, flight, flight, fuck)
– two branches that are controlled by brain SYMPATHETIC (preps for action – increases heart rate, sweat, dilates pupils, etc) and PARASYMPATHETIC (preps for rest and recuperation)
– uses neurotransmitter chemicals to communicate (aCh and NA)
What is the enteric nervous system (ENS)
• Half a billion neurons located in the gut
(in walls of gastrointestinal tract, from oesophagus to anus).
• Interacts with brain via Sympathetic and Parasympathetic NS, but can also function independently. Sometimes referred to as 2nd brain.
• Controls digestive activity (peristalsis and secretion of enzymes) and senses physical and chemical conditions of gut.
• Uses same neurotransmitters as in brain, including dopamine and serotonin (95% of all serotonin in body comes from gut).
What is so special about the neocortex?
It is convoluted. The thickness of the cortext is fixed (made up of 6 layers). It is folded on itself, to increase the total surface area of the cortex.
What are the four lobes of neocortex?
- Frontal lobes
- Parietal lobes
- Temporal lobes
- Occipital lobes
What is the meninges? What are its three parts?
It is a flexible sheet made from 3 membranes between bone and nervous tissue.
- dura mater – like canvas, flexible, durable
- arachnoid membrane – spongy, web-like with blood vessels passing through
- pia mater
What is the blood brain barrier? How much resource does brain use?
The blood vessels supplying blood to the CNS have special walls that restrict entry of many chemicals into CNS.
Brain is very energy demanding (<2% of body weight but needs 15% of total blood flow and uses 25% of oxygen consumption).
What is the spinal cord?
Spinal cord is a cable of neural fibres with “roots” branching off. It is an interface between the brain and the peripheral nervous system, i.e. it is directly connected to sensory, motor and autonomic nerves.
What is the brain responsible for?
Responsible for complex behaviours, thought, perception, and emotion.
What does the occipital lobe do?
At back of brain. Occipital lobes devoted to vision
What is the brainstem?
At the base of brain – controls life-supporting functions (heart rate, breathing, movement, things out of conscious awareness).
In the middle, so most protected (?). Damage to brainstem following head injury –> coma and death (increase in intracranial pressure squashes brainstem)
