Brain Bee 3

lower brainstem, involved in controlling breathing, heart rate, and blood pressure

Medulla

What is the first neurotransmitter to be identified?

Acetylcholine (ACh)

What does acetylcholine (ACh) do when released by neurons connected to voluntary muscles?

It causes them to contract.

What disease is characterized by fatigue and muscle weakness due to antibodies blocking a type of ACh receptor?

Myasthenia gravis

What is another important function of acetylcholine (ACh) besides muscle contraction?

It is important for memory.

- inhibit firing of neurons

- activity increased by benzodiazepines (anti-anxiety drugs)

GABA

- excitatory signals,

- activate NMDA receptors (important in learning/memory; however

overstimulation of these receptors can cause nerve cell damage or cell death)

GLUTAMATE

What is a key function of catecholamines related to movement?

Deficits cause Parkinson's disease.

What are common symptoms of Parkinson's disease?

Muscle tremors, rigidity, difficulty moving.

What is the most common treatment for Parkinson's disease?

LDOPA (levodopa), a precursor to dopamine.

How are abnormalities in dopamine related to cognition and emotion?

Abnormalities in dopamine have been identified in patients with schizophrenia.

What effect do many antipsychotic drugs have on dopamine?

They inhibit dopamine receptors.

What is a risk associated with the use of antipsychotic drugs?

Increased risk for tardive dyskinesia.

What are some symptoms of tardive dyskinesia?

Aimless, uncontrollable movements; rapid eye blinking.

What is a catecholamine?

A class of hormones that includes norepinephrine.

Where is catecholamine released from?

Adrenal medulla (innermost part of adrenal glands).

When is catecholamine released?

In times of stress.

What system secretes catecholamine to regulate heart rate and blood pressure?

Sympathetic nervous system.

- important in sleep, mood, depression, and anxiety

SEROTONIN

- important in sleep, mood, depression, and anxiety

- ex. cortisol (released by adrenal glands in response to stress)

HORMONES

1) nitric oxide

2) carbon monoxide

GASEOUS NEUROTRANSMITTERS

- important in sleep, mood, depression, and anxiety

- ex: the enzyme adenylyl cyclase converts ATP to the second messenger cAMP

SECOND MESSENGERS

Brain Development (3 Stages)

1) induction

2) proliferation

3) migration

ability of the brain to modify itself and adapt to challenges of the environment

Plasticity

programmed cell death initiated in the cells

Apoptosis

does 3⁄4 of focusing

Cornea

does the remainder of focusing after light has passed through cornea

Lens

adjusts size of pupil

Iris

centermost part of retina

Fovea

area around fovea, important for reading/driving

**macular degeneration = leading cause of blindness in elderly

Macula

location of photoreceptors

Retina

a) cones: color, bright light, acute detail

b) rods: dim light

Photoreceptors in Eye

Pathway by Which Light Travels in the Eye

cornea --> lens --> photoreceptors --> bipolar cells --> ganglion cells

In Thalamus, takes signal from optic nerves and acts as an intermediate relay

-sends information to primary visual cortex (occipital lobe)

Lateral Geniculate Nucleus

Made of axons of ganglion cells

Optic Nerve

What is the first part of the pathway of sound?

External ear (pinna + auditory canal)

What structure does sound waves hit after the external ear?

Tympanic membrane (eardrum)

What is the name of the bone that is also known as the hammer?

Malleus

What is the name of the bone that is also known as the anvil?

Incus

What is the name of the bone that is also known as the stirrup?

Stapes

What does the oval window separate?

Middle ear from inner ear

What part of the ear separates frequencies?

Cochlea

What cells in the cochlea are responsible for converting sound vibrations into neural signals?

Hair Cells in Cochlea

What nerve carries auditory information to the brain?

Auditory Nerve

Which part of the brain processes auditory information?

Auditory Cortex (Temporal Lobe)

On the cohclea's basilar membrane, converts mechanical vibration into electrical signals

Hair cells in Cochlea

Spinal Cord

Touch information is sent through...

Sensory fibers that respond to stimuli that damage tissue and can cause pain

Nociceptors

Enhance sensitivity of receptors to tissue damage and ultimately can induce more intense pain sensations, made by cyclo-oxygenase (COX) enzymes

Prostaglandins

Normally innocuous stimuli cause pain

Alldynia

Loss of ability to feel pain

Analgesia

Facts and events, "knowing what" --> primarily Hippocampus

Declarative Memory

General facts/data

Semantic Memory

Events

Episodic Memory

Unconscious and unintentional memory (example: playing the piano)

Nondeclarative Memory

Skills and habits

Procedural Memory

Attachment of emotional significance to memory

-AMYGDALA

Emotional Memory

Long lasting increase in strength of synaptic response following stimulation (occurs in hippocampus, involves NMDA receptors)

LTP

Language disorder

Aphasia

damage to left frontal lobe (Broca's area), inability to produce speech

Broca's aphasia

damage to left temporal lobe (Wernicke's area), inability to comprehend speech

Wernicke's aphasia

Voluntary movements, each muscle fiber controlled by one alpha motor neuron

Skeletal Muscle

An alpha motor neuron and all the muscle fibers it contains

Motor Unit

detect FORCE applied by contracting muscle, allowing brain to sense and control muscular force exerted during movement

Golgi Tendon Organs

What detects changes in length of muscle when stretched?

Muscle Spindle

Are all movements voluntary?

No, not all movements are voluntary.

What is the best example of involuntary movement?

Reflexes

What reflex occurs when the right foot encounters a sharp object?

Flexion (withdrawal) reflex

What happens to the right leg when it encounters a sharp object?

The right leg is immediately lifted from the source of potential injury.

What reflex helps maintain balance when one leg is flexed?

Crossed extension reflex

What does the left leg do in response to the right leg lifting from a sharp object?

The left leg responds with increased extension to maintain balance.

Non REM Sleep and REM Sleep

Phases of Sleep

What is the term for the type of sleep that includes slow wave sleep?

Non-REM Sleep

What physiological changes occur during slow wave sleep?

Relaxation of muscles, decrease in heart rate, blood pressure, and body temperature

Which part of the brain is involved in the active suppression of arousal systems during slow wave sleep?

Ventrolateral Preoptic Nucleus

What does REM stand for in sleep studies?

Rapid Eye Movement

What is atonia during REM sleep?

Paralysis of the body's muscles except for those controlling breathing and eye movements

What type of activity is associated with REM sleep?

Active dreaming

How do REM sleep cycles change during the night?

They become more prolonged until waking occurs

What system regulates timing of sleepiness and wakefulness throughout the day?

Circadian System

What group of cells in the hypothalamus regulates the circadian system?

Suprachiasmatic Nucleus

When stressed what three systems are activated?

-Voluntary Nervous System

-Autonomic Nervous System

-Neuroendocrine System

messages to muscle ("run away")

Voluntary Nervous System

excites sympathetic nervous system (pupils constrict, heart races, more blood to muscles, release of epinephrine aka adrenalin)

Autonomic Nervous System

Glutamate receiver in neurons

NMDA Receptor

Release of stress hormones (ex. cortisol)

Neuroendocrine System

measures blood flow, based on detection of radioactivity emitted when positrons undergo radioactive decay in brain

Positron Emission Tomography (PET)

provides three-dimensional image of brain structure using magnetic fields

Magnetic Resonance Imaging (MRI)

measures brain activity using electrodes placed on head

Electroencephalography (EEG)

impaired social skills; verbal and nonverbal communication difficulties; narrow, obsessive interests or repetitive behaviors

Autism

excessively inattentive, hyperactive, or impulsive behaviors

Attention Deficit Hyperactivity Disorder (ADHD)

medication of ADHD

methylphenidate

most frequently occurring chromosomal condition; low muscle tone, upward slant to eye, enlarged tongue, flat facial profile

Down Syndrome

genetic cause of Down Syndrome

extra copy chromosome 21

What is the most common learning disability?

Dyslexia

What type of difficulty is associated with dyslexia?

Unexpected difficulty in speaking and reading

In which groups is dyslexia commonly found?

Children and adults who otherwise possess intelligence

slowness of movement, muscular rigidity, walking/balance impairment, resting tremor

Parkinson's Disease

biological identifiers of Parkinson's

loss of dopamine producing neurons in substantia nigra

treatments of Parkinson's

levadopa (LDOPA)