PSYD13 Delkurs 1 - The Brain Flashcards
Who is Phineas Gage and why is the important in psychology?
Gage had a leisure in his frontal lobe which resulted in a change in personality/moral, which gave us gained knowledge in the functions of the frontal lobe
Which 2 parts can the nervous system be divided into?
The CNS and PNS
What does the CNS consist of?
The brain and the spinal cord
Which 2 (four) parts can the PNS be divided into?
The somatic system and the autonomic system (which can be divided into the sympathetic and parasympathetic nervous systems)
What is the PNS?
= contains all the neural structures that lie outside the brain and spinal cord
What is the somatic nervous system and what is its function?
The somatic nervous system contains of pairs of spinal and cranial nerves that are controlled by the CNS. It’s main function is voluntary muscle activation.
Spinal nerves
controlled and monitored by the spinal cord, receive information from the skin
Cranial nerves
controlled and monitored by the brain, both sensory and motor functions (both receives and sends information). Is a set of 12 paired nerves that control ex eye movement, tongue muscles, vision and so on
What is the autonomic nervous system (ANS) and what is its main function?
The ANS is divided into the sympathetic and parasympathetic systems. Its main function is the opposite of the somatic nervous system - it controls involuntary movement.
What is the sympathetic nervous system and what is its function?
It is also known as our fight or flight response. The CNS signals the sympathetic nervous system when we for example are in a stressful situation, and the sympathetic nervous system sends signals to for example our heart.
What is the parasympathetic nervous system and what is its function?
Known as the rest and digest response, the opposite to the sympathetic nervous system.
What bodily function does the sympathetic and parasympathetic nervous systems collaborate to attain?
Homeostasis!
What is homeostasis?
“a delicately balanced or constant internal state”,
What are neurons?
The functional building blocks of the nervous system; cells that transmit the electrical activity that underlies psychological processes
What are glial cells?
Glial = glue in greek. Glial cells serve to support neurons, by for example holding them in place and protecting them from toxins. Think for example myelin sheets! (oligodendrocytes in CNS and Schwann cells in PNS).
What are sensory and motor neurons?
Sensory neurons recieves and carries input from the sense organs to the spinal cord and the brain, whereas motor neurons carry output from the brain and the spinal cord to our body’s muscles and organs.
What are interneurons?
they perform connective or associative functions within the nervous system, for example, interneurons link sensory input from the visual system to our hippocampus, so that you can recognise a friend.
Soma?
Cell body
Dendrites?
receive information from the pre-synaptic neuron
Axon?
conducts electrical impulses away from the cell body to the post-synaptic neuron/muscles and glands
Axon terminals?
at the end of the axon one finds the axon terminals, where the electrical impulse is transmitted to the post-synaptic neuron with the help of neurotransmitters
Synapse (synaptic cleft)
the gap between the pre-synaptic neuron (the axon terminals) and the post-synaptic neuron (their dendrites).
Myelin sheath?
fatty layers made out of glial cells that surrounds the axon.
Nodes of ranvier
the gaps on the axon between the myelin sheath. The neural impulse “jumps” in the gaps which creates a quicker neural impulse.
What is the resting potential of a neuron?
The resting potential of a neuron is -70mV (compared to the intercellular space of 0 mV). One can think of the function of the resting potential as a charged arrow.
What is an action potential?
An action potential is the electrical shift across the cell membrane
How does an AP occur?
When the neuron recieves an electrical impulse and the axon hillock reaches the threshold (-50mV) -> voltage sensitive ion channels open and sodium (Na+) flows into the intercellular space -> 35mV = depolarisation
What happens after the AP (after the axon hillock has reached 35mV and sent an electrical impulse down the axon)?
After the AP during recovery (to the resting potential) potassium ions leave the intercellular (in attempt to recover the resting potential) which results in an absolute refractory period. During this period the neurons cannot receive any signals. Then,
What is a function of the absolute refractory period?
It ensures that the electrical impulse does not travel back down the axon, i.e. forces it to travel to the post-synaptic neuron.
What are graded potentials?
= local ionic concentration changes across the cell membrane, i.e. when changes in the resting potential do not reach the -50mV threshold. However, several graded potential can “together” trigger an AP in a post-synaptic neuron.
What is the all-or-none law?
the size and shape of the AP remains constant along the axon - this is because an AP triggers another AP along the axon, which creates a domino-effect.
Ion channels?
“Gates” that lets in or keeps out ions. They are what make the cell membrane selectively permeable, i.e. selectively keeps out or lets in ions.
Synaptic vesicles?
Chambers within the axon terminals that store neurotransmitters
Neurotransmitters?
Chemicals released by nerve cells that allows them to communicate with one another
Receptor sites?
Large protein molecules embedded in the receiving neuron’s cell membrane, i.e. the receptor molecules that binds neurotransmitters from the pre-synaptic neuron.
What does it mean that neurotransmitters can be either inhibitory or excitatory?
Excitatory: causes the post-synaptic neuron’s sodium channels to open -> influx of sodium -> AP
Inhibitory: either causes efflux of potassium (K+) or influx of chloride (Cl-) -> can inhibit the post-synaptic to reaching the AP threshold even if it recieves signals from other neurons.
What are the 5 steps of neurotransmission?
- Synthesis 2. Packaging and storage 3. Release 4. Receptor action 5. Inactivation
What is the function of Acetylcholine (ACh)?
Excitatory at synapses involved in muscular movement and memory
Disorders associated with Acetylcholine?
Alzheimers (undersupply) paralysis (absence) violent muscle contractions (oversupply)
What is the function of Noradrenaline?
Excitatory and inhibitory functions at various sites involved in neural circuits controlling learning, memory, wakefulness and eating
Disorders associated with Noradrenaline?
Depression (undersupply) stress and panic disorders (overactivity)
What is the function of Serotonin?
Inhibitory or excitatory: involved in mood, sleep, eating and arousal, and may be important transmitter underlying pleasure and pain
Disorders associated with Serotonin?
Depression; sleeping and eating disorders (undersupply) OCD (overactivity)
What is the function of Dopamine?
Excitatory; involved in voluntary movement, emotional arousal, learning, memory, and experiencing pleasure or pain