Brain and Nervous System (Excluding Specific Brain Regions) Flashcards
How MIGHT patients with dementia be able to improve their cognitive function?
Do cognitive tasks, like arithmetic or reading aloud
Left vs. Right Hemispheres
Left: more analytical, rational
Right: more creative, artistic, intuitive
Talk about the “humans only use 10% of their brain” claim
Humans have access to 100%. Damage of a tiny part of the brain can have dramatic effects. Even in sleep, we use much more than 10%
2 Main Parts of Nervous System
1) Central Nervous System
2) Peripheral (outlying) Nervous System
Central Nervous System (CNS)
What does it consist of? What functions?
Consists of the brain and the spinal cord
Function: receive, process, interpret, and store sensory information. send out messages to muscles, glands, and internal organs.
How’s the spinal cord related to the brain?
The spinal cord is an extension of the brain, extending to below the neck. Messages are carried from brain to (and through) spinal cord
Spinal reflexes
Examples?
Automatic behaviors that the spinal cord produces without the brain (or conscious effort). The brain doesn’t have time to register.
eg. pulling away from hot pot.
How do thoughts and emotions interact with spinal reflexes?
Some thoughts or emotions might trigger or inhibit spinal reflexes (eg. penile erection)
Peripheral Nervous System (PNS)
What does it consist of? What functions?
All portions of nervous system outside of CNS, including sensory and motor nerves.
Function: Handles nervous system’s input and output.
What’s the function of motor nerves?
Carries orders from CNS to muscles, glands, and organs. Enables movement and enables glands to secrete substances like hormones.
2 Parts of the Peripheral Nervous System
Somatic Nervous System and Autonomic Nervous System
Somatic Nervous System
what is it? its function?
Consists of nerves that are connected to sensory receptors
Function: Enables us to sense the world and have voluntary action.
Autonomic Nervous System
what does it consist? function?
Consists of nerves that are connected throughout the body.
Function: Regulates functioning of blood vessels, glands, internal organs. (eg. when you see your crush and you flush)
2 Divisions of Autonomic Nervous System
1) Sympathetic Nervous System
2) Parasympathetic Nervous System
How do the sympathetic and parasympathetic nervous system work?
The sympathetic nervous system mobilizes the body for action (blushing, sweating, increasing heart rate, fight/flight etc.) while the parasympathetic nervous system slows things down
Which division of the Autonomic Nervous System inhibits bladder contraction? which allows bladder contraction?
Sympathetic inhibits bladder contraction
The brain is made of how many types of cells? What are they?
Two types. Neurons and Glial cells
What is the function of neurons? What is the function of Glia (glial cells)?
Neurons are nerve cells. Transmit information to, from, and within the CNS.
Glia hold neurons in place and protect them. They also help neurons grow, protect brain from toxic agents, etc.
How many cells are in an adult brain? How much is each type of cell?
171 Billion. Half and half (glia and neurons)
Do neurons mostly look the same throughout the brain? How many types of neurons in mammals?
No, they vary depending on location and function. 200 types.
Three main parts of a neuron
Dendrites, cell body, and axon
What’s the range of the size of axons in adult humans?
From four thousandths of an inch to a few feet
Axon Terminal
The ends of axons that communicate with other neurons
Myelin Sheath
Functions?
A layer of fatty material found around many axons, made of glial cells.
Function: to prevent adjacent cells from interfering with each other and speed up conduction of neural impulses
Nodes
Constrictions in myelin sheath, making the axon look like link sausages.
Nerves
Axons and sometimes dendrites bundled in PNS. Mostly enter or leave spinal cord.
How many peripheral nerves in human body?
43 pairs. (one left one right of body for each pair)
Cranial nerves
12 pairs of nerves in the head that connect directly to the brain.
Neurogenesis
The production of new neurons from immature stem cells.
Stem cells
Immature cells that renew themselves and have the potential to develop into mature cells
When do stem cells stop maturing?
They divide and mature throughout adulthood (some suggest adolesence)
What can kill new cells? What can inhibit their production?
Nicotine. Binge drinking alcohol, aging, and stress can inhibit their production.
What are some potential benefits of stem cell research?
Restoring sight in those who are legally blind, healing damaged heart tissue, etc.
Synaptic cleft
A small space between axon of one neuron and dendrite or cell body of another. Neurons don’t touch each other.
Synapse (vs. Synaptic Cleft)
Synapse is the entire site where nuerons interact (axon terminal, synaptic cleft, and receptor sites)
Explain how neurons speak to one another. (chemistry)
At rest, neurons have negative charge inside the cell. When stimulated, positively charged sodium ions enter, making neuron less negative. It then triggers action potential, which opens the gates of axon membrane, allowing even more positively charged sodium in, making the neuron positively charged. Then, the neuron “fires”, and positively charged potassium ions move from the axon to the outside, restoring the cell to its negative charge in its resting state.
Neurotransmitter
A chemical substance released by a neuron at the synapse, influencing the activity of the receiving neuron
What do neurotransmitters do to the charge of a neuron?
Some neurotransmitters decrease negative charge, making it more likely to fire (excitatory effect) while some increase negative charge (inhibitory effect).
Why are inhibition (neurotransmitters) important in nervous system?
Allows us to sleep and coordinate movements. Too much excitation will cause convulsions
Serotonin function
Affects neurons involved in sleep, appetite, sensory perception, temperature regulation, pain suppression, mood
Dopamine function
Affects neurons involved in voluntary movement, attention, learning, memory, emotion, pleasure and reward, and responses to novelty
Acetylcholine function
Affects neurons involved in muscle action, arousal, vigilance, memory, and emotion
Norepinephrine
Affects neurons involved in learning, memory, dreaming, waking from sleep, and emotion
GABA (gamma aminobutyric acid)
Major inhibitory neurotransmitter. Controls hyperactivity (in eg. stress/anxiety).
Glutamate
Major excitatory neurotransmitter released by about 90% of brain’s neurons. Memory, cognition, emotion regulation
Abnormal GABA levels are related to what disorders?
Sleep, eating, and convulsive disorders
What neurotransmitters have to do with learning, memory, and emotion?
Norepinephrine and Dopamine
What happens to serotonin levels after a protein-rich meal vs. a high-carbs meal?
Protein-rich: decreases serotonin.
High-carb: increases serotonin.
Hormones
Chemical substances secreted by glands that affect the functioning of other organs
Endocrine Glands
Organs that produce hormones and release them to the bloodstream (eg. ovaries, testes, adrenal glands)
Melatonin
Function
A hormone secreted by pineal gland
Function: regulates daily biological rhythms, promotes sleep
Oxytocin
Function?
A hormone secreted by the pituitary gland
Function: Enhances uterine contractions in childbirth, ejecting of milk in nursing. Promotes social attachment (along with vasopressin)
Adrenal hormones
Function?
Produced by adrenal glands
Function: Emotion and stress. Adrenal glands produce cortisol, epinephrine, and norepinephrine.
Sex hormones
Function?
Secreted by tissue in the gonads (testes/ovaries) and by adrenal glands
Function: Helps facilitate puberty changes, sexual arousal, and other sexual functions
Role of Testosterone
Testosterone: masculinizing hormones mainly produced in testes. Deepened voice, facial/chest hair, pubic/underarm hair, and sexual arousal.
Role of Estrogens
Feminizing hormones that bring physical changes like breast development and menstruation. Helps learning and memory, indirectly produces acetylcholine
Progesterone function
A hormone. Growth and maintenence of uterine lining in preparation of fertlized egg.
Endorphines
Function?
Can be both a neurotransmitter or hormone.
Reduce pain, promote pleasure. Appetite, sexual activity, blood pressure, mood, learning, memory
Why do endorphin levels shoot up under stress?
Endorphins allow pain to be bearable, which makes taking action easier (evolutionary advantage)
How are endorpins related to social bonding?
Blocking effects of endorphins reduces self-reported feelings of social connection.
Endorphin rush occurs in early stages of passionate love, when “falling” for someone.
In infancy, bonding with mother stimulates flow of endorphins
What is a lesion?
What’s the lesion method?
Surgically removing or damaging a part of the brain.
Lesion method: Removal or disabling non-human animal’s brain structure to better understand its function
Transcranial Magnetic Stimulation (TMS)
How might it be used in clinical settings?
Manipulating the brain by using a powerful magnetic field produced by a wire coil on a person’s head. (current is 40,000 times greater than earth’s natural magnetic field). Successful in treating depression.
Transcranial Direct Current Stimulation (tDCS)
What has this found to help?
Apply small electric current to an area of cortex
Helps motor functioning after stroke and alleviates symptoms of depression
Transcranial Alternating Current Stimulation (tACS)
What might it help with?
Low-intensity ‘waves’ of alternating electrical current. Alters brain waves to match frequency of tACS waves.
Might enhance performance on tasks with working memory, problem solving, and perception. Can be used to treat cognitive impairmentzoo
Electroencephalogram (EEG)
What’s a con of it?
Using electrodes to look at brain waves. Not very precise.
Event-related potentials (ERPs)
How does this solve what EEG lacks? How does it not?
Waves of neural activity associated with specific stimuli. Solves the issue of knowing when something occurs, but still not where.
Positron Emission Tomography (PET) scan
What’s an example with glucolse?
Records biochemical activity in the brain.
Inject glucose-like substance with radioactivity, which accumulates in brain areas that are particularly active and is detected by the scsan.
Magnetic Resonance Imaging (MRI)
Use of powerful magnetic fields and radio frequencies to take detailed pictures of the brain. Looks at strength and duration, converts to high-contrast picture.
Functional Magnetic Resonance Imaging (fMRI)
What is its advantage over EEG? What is it not good at?
Allows to see brain activity for at least a few seconds. Detects bloody oxygen levels in brain areas. (neurons use oxygen for fuel, so active areas will have bigger signal)
Can detect activity pretty precisely. Less precise in determining when something occurs.
What was Franz Joseph Gall wrong about? What was he right about?
There are such things as localized functions in the brain. But lots overlap. And phrenology was wrong. Personality traits are not reflected in specific areas of brain.
Which side hemisphere damaged might lead to language and speech issues?
Left hemisphere
What happens when the two sides of the brain are cut off from each other?
Each side of the brain is clueless about what the other side is doing.
Eg. verbally saying what they saw verses pointing with hand can have different answers
Why is ‘left-brained’ and ‘right-brained’ stuff in pop psych inaccurate?
1) it’s to a matter of degree what each side does.
2) they are not competing, but rather help each other out. not on a spectrum.
Sex differences in cortex, brain volume.
What about hippocampus, amygdala, frontal lobes, and motor areas?
On average, cortex is thicker in women, brain volume greater in men.
Hippocampus, amygdala, and motor areas larger in men. Frontal lobes larger in women.
