The Human Brain Flashcards
What is the key building block of the brain?
The neuron is the key building block of the brain. The cell body receives inputs from dendrites or axons of other neurons and sends its output via the axon.
What happens when the total excitatory input to a neuron sufficiently exceeds the total inhibitory input?
The neuron fires, and chemical reactions occur down the axon, leading to the release of neurotransmitter substances at the terminal buttons.
What is the cerebral cortex?
The cerebral cortex is the largest part of the brain, a folded mass of gray matter divided into two hemispheres.
What are the four lobes of the brain and their functions?
- Occipital lobe: Processes vision.
- Temporal lobe: Processes sound, interprets language, and stores memories.
- Frontal lobe: Provides motor control, reasoning, attention, and emotions.
- Parietal lobe: Controls spatial awareness and sense of touch.
What is the function of the left hemisphere?
The left hemisphere is more effective at speech, reasoning, and processing language.
What is the function of the right hemisphere?
The right hemisphere is more effective at spatial perception and processing nonverbal cues.
What are the key structures below the cortex?
- Thalamus: The switching center of the brain, relaying sensory and motor signals.
- Hypothalamus: Controls many automatic bodily functions like temperature, heart rate, and hunger.
- Limbic system: Plays a role in emotions and memory.
- Cerebellum: Manages balance, coordination, and timing.
- Brainstem: Relays information from the spinal cord and controls vital functions like breathing.
Which lobe is involved in motor control, memory search, speech, reasoning, and emotions?
The frontal lobe is involved in these functions.
How is a signal transferred from one neuron to the next?
signal is captured by a neuron’s dendrites, processed in the nucleus, then moves down the axon to the terminal buttons, which send the message across the synaptic cleft to the next neuron.
What is the role of the sympathetic nervous system?
The sympathetic nervous system prepares the body for physical exertion or excitement, like showing excitement when winning a game.
What are neurons, and what do they do?
Neurons are the basic units of the nervous system that process thousands of signals and produce outputs that guide everything we think, feel, and do.
What are the main structures of a neuron?
- Dendrites: Receive signals from other neurons.
- Cell Body (Soma): Contains the nucleus and processes signals.
- Axon: Transmits output signals to other neurons, muscles, or glands.
- Terminal Buttons: Release neurotransmitters into the synapse.
How do neurons communicate?
Neurons communicate by firing electrical signals. When stimulated, ion exchange occurs in the axon membrane, sending an electrical signal to the terminal buttons, releasing neurotransmitters into the synaptic cleft.
What is the All-or-None Law?
A neuron either fires completely or does not fire at all. If enough input is received, the neuron fires and releases neurotransmitters.
What are the three components of a synapse?
- Axon terminal of the sending neuron.
- Dendrites or cell body of the receiving neuron.
- Synaptic cleft (gap) between them.
What is the role of neurotransmitters?
Neurotransmitters are chemical messengers that travel across the synaptic cleft, binding to receptors on the receiving neuron, triggering or inhibiting a neural impulse.
What does Acetylcholine do, and what disorders are associated with it?
Acetylcholine causes muscle contraction, influences memory, and arousal. Disorders: Alzheimer’s, delusions (shortage); tremors, spasms (excess).
What does Dopamine do, and what disorders are associated with it?
Dopamine is involved in motivation, reward, movement, learning, and thought. Disorders: Parkinson’s disease, depression, ADHD (shortage); aggression, schizophrenia (excess).
What does Noradrenaline (Norepinephrine) do?
Noradrenaline affects dreaming and attention. Disorders: Depression, fatigue (shortage); anxiety, schizophrenia (excess).
What is Glutamate’s role in the brain?
Glutamate is the primary excitatory neurotransmitter involved in learning and memory. Disorders: Schizophrenia, mood disorders.
What do Endorphins do?
Endorphins are involved in pain perception and modulation. Disorders: Anxiety, substance abuse.
What is Serotonin responsible for?
Serotonin regulates mood, sleep, and inhibition. Disorders: OCD, insomnia, depression (shortage); sleepiness, lack of motivation (excess).
What does GABA (Gamma-aminobutyric acid) do?
GABA is the primary inhibitory neurotransmitter. Disorders: Anxiety, panic, epilepsy, Huntington’s disease (shortage); sluggishness (excess).
What are Endogenous Cannabinoids involved in?
Endogenous Cannabinoids affect memory, attention, emotion, movement, and appetite. Disorders: Chronic pain (shortage); schizophrenia, eating disorders (excess).
How do drugs affect neurotransmitters?
Drugs can mimic, block, or increase neurotransmitter activity, influencing disorders such as depression, Parkinson’s, anxiety, and more.
What are the roles of receptors in neurons?
Receptors on neurons bind to specific neurotransmitters. Excitatory inputs make neurons more likely to fire, while inhibitory inputs reduce the likelihood of firing.
What are glial cells, and what do they do?
Glial cells support neuron function, clean up dead neurons, maintain the neural environment, and help form synapses and connections in the brain.
What did research on Einstein’s brain reveal about glial cells?
Einstein had a higher ratio of glial cells to neurons, particularly in areas of imagination and complex thinking, suggesting glial cells play a role in higher cognitive processes.
What are the two main divisions of the nervous system?
The nervous system is divided into the Central Nervous System (CNS), which consists of the brain and spinal cord, and the Peripheral Nervous System (PNS), which connects the CNS to the rest of the body.
What are the two branches of the Peripheral Nervous System (PNS)?
- Somatic Nervous System: Controls voluntary movements (e.g., movement of muscles).
- Autonomic Nervous System (ANS): Controls involuntary body functions such as digestion and circulation.
What are the two parts of the Autonomic Nervous System (ANS)?
- Sympathetic Nervous System: Activates the body’s fight-or-flight response during emergencies.
- Parasympathetic Nervous System: Calms the body down after a threat has passed.
