Brain Bee 1 Flashcards
How many pounds does the brain weigh
3 Lb
How many neurons does the brain have?
100 billion neurons
What is a dendrite? 👩🦽➡️🧑🦼..👨🦼➡️
PRIMARY site* for RECEIVING and integrating information *from other neurons 👨🦼➡️
Axon 🦑
FIBER-like** 🦑 extension of neuron by WHICH it sends INFOrmation to TARGET cells
What is action potential? ⚡️
ELECTRICAL charge** ⚡️ that travels** along the neuron’s TERMINAl where it triggers the RELEASE of **neurotransmitters
Neurotransmitter 💨
A chemical** released by neurons at SYNAPSE for the purpose of relaying information to other neurons via RECEPTORS*
Nodes of ranvier 👽
GAPS* occurring in the MYELIN SHEATH** that allows for faster CONDUCTION** of **action POTENTIAL
Frontal
initiating and coordinating motor movements;
higher cognitive skills (problem solving, thinking, planning);
personality; emotion; e
PARIETAL
sensory processes, attention, language
OCCIPITAL
vision
TEMPORAL
auditory information, memory
cerebrum
largest part of the human brain
cerebral cortex
sheet of tissue covering the outermost layer of
the cerebrum
ventricles
hollow spaces in brain containing cerebrospinal fluid
• white matter:
axons of neurons (white in appearance because of fatty myelin that covers axons
• corpus callosum:
large white matter structure linking the left and right cerebral hemisphere
- thalamus: l
gate and modulate flow of information to cortex
What is the role of the hypothalamus?
Responsible for hormone production (e.g., GnRH, CRH) and communicates with the pituitary gland.
Also contains important groups of cells.
What is the function of the ventrolateral preoptic nucleus? Hint: nerve
Contains nerve cells with GABA and galanin, important for sleep.
What is the role of orexin-containing nerve cells?
Important in wakefulness.
What does the suprachiasmatic nucleus do?
Acts as a master clock.
What is the substantia nigra and its significance?
Part of the basal ganglia, important for movement; dopaminergic neurons here degenerate in Parkinson’s disease.
What is the shape and importance of the hippocampus?
Shaped like a seahorse; very important for memory.
What is the role of the amygdala?
Important in fear and emotion; responsible for the emotional aspect of memory.
What is the pons?
Upper brainstem, attached to the cerebellum.
What does the medulla control?
Involved in controlling breathing, heart rate, and blood pressure.
What is the function of the cerebellum?
Helps adjust motor output to changing conditions; important for coordination and balance; attached to the pons.
What is acetylcholine (ACh)?
First neurotransmitter to be identified.
What role does acetylcholine (ACh) play in muscle contraction?
Released by neurons connected to voluntary muscles causing them to contract.
What disease is associated with antibodies blocking ACh receptors?
Myasthenia gravis, characterized by fatigue and muscle weakness.
What is another important function of acetylcholine (ACh)?
Also important for memory.
What is the function of GABA?
Inhibit firing of neurons.
How do benzodiazepines affect GABA?
Activity increased by benzodiazepines (anti-anxiety drugs).
What is the role of glutamate?
Excitatory signals.
What receptors does glutamate activate?
Activates NMDA receptors, important in learning/memory.
What can overstimulation of NMDA receptors cause?
Can cause nerve cell damage or cell death.
What are the three important functions of dopamine?
- Movement
- Cognition and Emotion
- Endocrine system
How is dopamine related to movement?
Deficits in dopamine are associated with Parkinson’s disease, which includes symptoms like muscle tremors and rigidity.
Most common treatment for Parkinson’s is LDOPA (or levodopa), a precursor to dopamine.
What is the relationship between dopamine and cognition/emotion?
Abnormalities in dopamine have been identified in patients with schizophrenia. Many antipsychotic drugs inhibit dopamine receptors, increasing the risk for tardive dyskinesia.
What is norepinephrine’s role during stress?
Norepinephrine is released from the adrenal medulla in times of stress and is secreted by the sympathetic nervous system to regulate heart rate and blood pressure.
What is serotonin important for?
Serotonin is important in sleep, mood, depression, and anxiety.
What are hormones important for?
Hormones are important in sleep, mood, depression, and anxiety.
Example: cortisol (released by adrenal glands in response to stress)
What are the two gaseous neurotransmitters?
The gaseous neurotransmitters are nitric oxide and carbon monoxide.
What are second messengers important for?
Second messengers are important in sleep, mood, depression, and anxiety.
Example: the enzyme adenylyl cyclase converts ATP to the second messenger cAMP.
What are the three stages of brain development?
The three stages of brain development are induction, proliferation, and migration.
What does plasticity refer to in the brain?
Plasticity refers to the ability of the brain to modify itself and adapt to challenges of the environment.
What is apoptosis?
Programmed cell death initiated in the cells.
What does the cornea do?
The cornea does ¾ of focusing.
What is the function of the lens?
The lens does the remainder of focusing after light has passed through the cornea.
What is the role of the iris?
The iris adjusts the size of the pupil.
What is the fovea?
The centermost part of the retina.
What is the macula?
The area around the fovea, important for reading/driving.
What is macular degeneration?
Leading cause of blindness in the elderly.
Where are photoreceptors located?
In the retina.
What are the two types of photoreceptors?
Cones and rods.
What do cones do?
Cones are responsible for color, bright light, and acute detail.
What do rods do?
Rods function in dim light.
What is the pathway by which light travels in the eye?
Cornea → lens → photoreceptors → bipolar cells → ganglion cells.
What forms the optic nerve?
The axons of ganglion cells.
Where does the signal from the optic nerve go?
To the lateral geniculate nucleus of the thalamus, and then to the primary visual cortex (occipital lobe).
What is the pathway of sound waves in hearing?
Sound waves → external ear (pinna + auditory canal) → tympanic membrane (eardrum) → malleus (hammer) → incus (anvil) → stapes (stirrup) → oval window (separates middle ear from inner ear) → cochlea (separates frequencies).
What do hair cells in the cochlea do?
They convert mechanical vibration to electrical signals.
How does the auditory signal travel?
Via the auditory nerve to the auditory cortex (temporal lobe).
How do touch receptors work?
Receptors on different parts of the body send ‘touch’ messages to the cortex via the spinal cord.
Which body parts are more sensitive to touch?
Lips and hands have more cortex devoted to them.
What is the two-point threshold?
The distance between two points on the skin necessary for an individual to distinguish two distinct stimuli from just one.
What are nociceptors?
Sensory fibers that respond to stimuli that damage tissue and can cause pain.
What role do prostaglandins play in pain sensation?
They enhance sensitivity of receptors to tissue damage and can induce more intense pain sensations, made by cyclooxygenase (COX) enzymes.
What is allodynia?
A condition where normally innocuous stimuli cause pain.
What is analgesia?
Loss of ability to feel pain.
What is declarative memory?
Memory of facts and events, known as ‘knowing what’, primarily associated with the hippocampus.
What are the two types of declarative memory?
1) Semantic memory: general facts/data. 2) Episodic memory: events.
What is nondeclarative memory?
Unconscious and unintentional memory, known as ‘knowing how’.
What are the types of nondeclarative memory?
1) Procedural memory: skills and habits. 2) Emotional memory: attachment of emotional significance to memory (involves amygdala). 3) Movement memory: involves cerebellum.
What is LTP?
Long lasting increase in strength of synaptic response following stimulation, occurs in hippocampus and involves NMDA receptors.
What is aphasia?
A language disorder.
What is Broca’s aphasia?
Damage to left frontal lobe (Broca’s area) resulting in inability to produce speech.
What is Wernicke’s aphasia?
Damage to left temporal lobe (Wernicke’s area) resulting in inability to comprehend speech.
What is skeletal muscle?
Muscle responsible for voluntary movements.
What is a motor unit?
An alpha motor neuron and all the muscle fibers it contains.
What do Golgi tendon organs detect?
Force applied by contracting muscle, allowing the brain to sense and control muscular force exerted during movement.
What do muscle spindles detect?
Changes in length of muscle when stretched.
What is an example of involuntary movement?
The best example of involuntary movement is reflexes.
What are the flexion and crossed extension reflexes?
When the right foot encounters a sharp object, the right leg is lifted (flexion) and the left leg extends to maintain balance (crossed extension).
What are the two phases of sleep?
The two phases of sleep are non-REM sleep and REM sleep.
What occurs during non-REM sleep?
Non-REM sleep includes relaxation of muscles, decreased heart rate, blood pressure, and body temperature, with active suppression of arousal systems by cells in the ventrolateral preoptic nucleus.
What occurs during REM sleep?
During REM sleep, there is atonia (paralysis of muscles) except for those controlling breathing and eye movements, along with active dreaming.
How does the circadian system function?
The circadian system regulates timing of sleepiness and wakefulness throughout the day, controlled by the suprachiasmatic nucleus in the hypothalamus.
What systems are activated by stress?
Stress activates the voluntary nervous system, autonomic nervous system, and neuroendocrine system.
What is the role of the autonomic nervous system during stress?
It excites the sympathetic nervous system, causing pupils to constrict, heart to race, more blood to muscles, and release of epinephrine (adrenaline).
What does positron emission tomography (PET) measure?
PET measures blood flow based on detection of radioactivity emitted when positrons undergo radioactive decay in the brain.
What does magnetic resonance imaging (MRI) provide?
MRI provides a three-dimensional image of brain structure using magnetic fields.
What does electroencephalography (EEG) measure?
EEG measures brain activity using electrodes placed on the head.
What are the characteristics of Autism?
Autism is characterized by impaired social skills, verbal and nonverbal communication difficulties, and narrow, obsessive interests or repetitive behaviors.
What are the symptoms of Attention Deficit Hyperactivity Disorder (ADHD)?
ADHD symptoms include excessively inattentive, hyperactive, or impulsive behaviors.
What is the most frequently occurring chromosomal condition?
Down Syndrome, characterized by low muscle tone, upward slant to the eye, enlarged tongue, and flat facial profile.
What genetic cause is associated with Down Syndrome?
Down Syndrome is caused by an extra copy of chromosome 21.
What is Dyslexia?
Dyslexia is the most common learning disability, characterized by unexpected difficulty in speaking and reading in individuals who otherwise possess intelligence.
What is Alzheimer’s disease?
Alzheimer’s disease is a progressive, degenerative disorder attacking neurons, resulting in loss of memory, cognition, and behavioral changes.
What are the biological identifiers of Alzheimer’s disease?
The biological identifiers include abnormal accumulation of beta amyloid (neuritic plaques) and tau (neurofibrillary tangles).
What genetic causes are associated with Alzheimer’s disease?
Genetic causes include presenilin 1 and 2, and APOE epsilon 4.
What treatment is available for Alzheimer’s disease?
Drugs preventing the breakdown of acetylcholine are used as treatment.
What is Amyotrophic Lateral Sclerosis (ALS)?
ALS, also known as Lou Gehrig’s disease, is characterized by progressive muscle weakness resulting in paralysis.
What is the biological identifier of ALS?
The biological identifier is the degeneration of motor neurons in the brain and spinal cord.
What genetic cause is associated with ALS?
A mutation in the gene coding for superoxide dismutase is associated with ALS.
What are the symptoms of Huntington’s Disease?
Huntington’s Disease is characterized by involuntary jerking movements of limbs, torso, and facial muscles.
What genetic cause is associated with Huntington’s Disease?
An expanded triplet repeat in the gene that codes for huntingtin is the genetic cause.
What are the symptoms of Parkinson’s Disease?
Parkinson’s Disease symptoms include slowness of movement, muscular rigidity, walking/balance impairment, and resting tremor.
What is the biological identifier of Parkinson’s Disease?
The biological identifier is the loss of dopamine-producing neurons in the substantia nigra.
What treatment is available for Parkinson’s Disease?
Levodopa (LDOPA) is used, which converts to dopamine in the brain.
What is current research focused on regarding Parkinson’s Disease?
Current research uses rodent/non-human primate models treated with MPTP to learn more about the disease and possible treatment.
What is Tourette Syndrome?
Motor and vocal tics; males are 3-4 times more likely to be affected.
What are the treatments for Tourette Syndrome?
Antipsychotics, SSRIs (selective serotonin reuptake inhibitors), stimulants (methylphenidate).
What are the symptoms of Schizophrenia?
Hallucinations, delusions, lack of motivation, flat affect.
What is a biological identifier of Schizophrenia?
Enlarged ventricles, abnormal levels of dopamine.
What is the treatment for Schizophrenia?
Chlorpromazine (first antipsychotic drug); other antipsychotics blocking dopamine receptors (may result in tardive dyskinesia).
What are the symptoms of Obsessive Compulsive Disorder (OCD)?
Repetitive thoughts and behaviors.
What is the treatment for OCD?
SSRIs.
What characterizes Post Traumatic Stress Disorder (PTSD)?
Following some type of trauma (war, car accident, etc); intense fear and helplessness.
What is the treatment for PTSD?
Beta blockers (block norepinephrine receptors).
What are the symptoms of Panic Disorder?
Overwhelming sense of impending doom, sweating, weakness, dizziness.
What is the treatment for Panic Disorder?
SSRIs, antidepressants.
What are the symptoms of Major Depression?
Hopelessness, pessimism, loss of interest.
What is the treatment for Major Depression?
Antidepressants, SSRIs.
What characterizes Bipolar Disorder?
Cycling between deep depression and manic highs.
What are the treatments for Bipolar Disorder?
Lithium, anticonvulsants (Valproate).
What are the types of brain tumors?
Primary (arise within brain) and secondary (metastatic, arise in other parts of body).
What is a type of primary brain tumor?
Gliomas, which release glutamate at toxic concentrations.
What is the treatment for brain tumors?
Surgery, drugs that relieve swelling.
What are the symptoms of Multiple Sclerosis (MS)?
Blurred vision, slurred speech, weakness, tremors, memory loss.
What is the biological cause of Multiple Sclerosis (MS)?
Body attacks myelin sheath covering axon, leaving scleroses (scars).
What are the symptoms of Traumatic Brain Injury (TBI)?
Concussion, cerebral edema (swelling), lesions, bruises.
What is the treatment for Traumatic Brain Injury (TBI)?
Removal of cerebrospinal fluid, hyperventilation, removal of parts of skull.
What are the characteristics of Epilepsy?
Seizures, can be idiopathic or symptomatic, characterized as generalized or partial.
What is the treatment for Epilepsy?
Antiepileptics.
What causes a Stroke?
Clot in blood vessel cuts off blood supply to brain; paralysis and loss of speech are common.
What is the treatment for Stroke?
Tissue plasminogen activator (tPA), arterial stent, anticoagulants.
What is Tardive Dyskinesia?
Involuntary, repetitive movements; may be a side effect of antipsychotics blocking dopamine receptors.
What is Myasthenia Gravis?
Autoimmune disorder in which acetylcholine receptors are blocked, resulting in muscle weakness and fatigue.
What is Fetal Alcohol Syndrome?
Leading preventable cause of mental retardation; mental and physical defects in fetus associated with high levels of alcohol consumption during pregnancy.
What is Korsakoff’s Syndrome?
Cognitive decline/memory loss associated with chronic alcoholism.
What is Narcolepsy?
Poor control of sleep-wake cycles leading to sudden bouts of sleep.
What is the biological cause of Narcolepsy?
Death of cells in hypothalamus containing orexin.
What is REM Behavior Disorder?
Muscles fail to become paralyzed during REM sleep, causing individuals to act out dreams.
What is Obstructive Sleep Apnea?
Airway muscles in throat relax during deep sleep, closing airway and resulting in difficulty staying asleep.
