Psych 1102 - Week 3: The Nervous System and Brain Genetics

Flashcards covering the nervous system structure, brain anatomy, neurotransmitters, neural transmission, and basic human genetics.

What three basic parts compose a neuron?

The three basic parts of a neuron or nerve cell are the cell body, dendrites, and axon.

What is the function of dendrites in a neuron?

Dendrites are projections from the cell body that pick up impulses from other neurons.

What is the role of an axon in a neuron?

The axon is a nerve fiber projecting from the cell body that carries nerve impulses.

What is the function of the myelin sheath?

The myelin sheath is a fatty coat that insulates the axons of some nerve cells, speeding transmission of impulses.

What is a node on an axon and what function does it serve?

A node is a gap in the myelin sheath of an axon that helps the conduction of nerve impulses.

Where are neurotransmitters stored before release at the end of a neuron?

Neurotransmitters are contained inside synaptic vesicles within terminal buttons (synaptic knobs) located at the end of the axon.

How do neurotransmitters bind to the postsynaptic neuron after release into the synaptic cleft?

Neurotransmitters are released into the synapse (or synaptic gap/cleft) and bind to receptor sites on the next neuron if they fit like a lock and key.

Which neurological and psychiatric disorders are associated with imbalances in dopamine?

Too much dopamine is thought to be related to schizophrenia, while too little dopamine is thought to be related to Parkinson's disease.

What functions are influenced by epinephrine (adrenaline)?

Epinephrine affects arousal, memory storage, and metabolizing glucose for energy.

How are abnormal levels of norepinephrine (NE) linked to psychiatric disorders?

Too little norepinephrine is linked to depression, whereas too much norepinephrine is linked to mania and agitation.

What cognitive functions are associated with glutamate?

Glutamate is associated with many cognitive functions such as learning and memory.

What bodily functions and conditions are linked to acetylcholine (ACh)?

Acetylcholine is associated with voluntary movement of skeletal muscles, learning and memory in the brain, Alzheimer's disease, sexual behavior, and rapid-eye-movement (REM) stages of sleep.

What role does serotonin (5-HT) play in mood disorders and how do SSRIs function?

Serotonin in the synapses may be a cause of depression; SSRIs (Selective Serotonin Reuptake Inhibitors like Prozac) allow for more serotonin to be available. It is also involved in personality, hunger, arousal, sexual activity, aggression, obesity, temperature regulation, sleep onset, and pain modulation.

What is the primary effect of GABA and what conditions are linked to its levels?

GABA (Gamma-aminobutyric acid) has a calming effect. Too little GABA is thought to be related to anxiety disorders, while too much may be related to Huntingdon's Chorea.

What structural hierarchy of the nervous system is shown in this figure?

The Nervous System divides into Peripheral and Central systems; Peripheral divides into Autonomic and Somatic; Autonomic divides into Sympathetic and Parasympathetic; Somatic divides into Sensory Input and Motor Output.

What are the components of the Central Nervous System versus the Peripheral Nervous System?

The Central Nervous System consists of the brain and spinal cord, while the Peripheral Nervous System extends outside the CNS throughout the body's torso and extremities (arms, legs, hands, feet).

How do the sympathetic and parasympathetic divisions of the autonomic nervous system differ in function?

The sympathetic division activates under pressure, while the parasympathetic division maintains body functions.

What three major divisions of the brain are shown in this diagram?

The three major divisions of the brain are the Forebrain, Midbrain, and Hindbrain.

What are the four primary structures of the hindbrain?

The four primary structures of the hindbrain are: (1) Reticular Formation or Reticular Activating System (RAS), (2) Pons, (3) Medulla Oblongata, and (4) Cerebellum.

What structures compose the midbrain and what function does the RAS serve?

The midbrain consists of the substantia nigra, superior colliculi, and inferior colliculi. It also contains the Reticular Activating System (RAS), which regulates cortical arousal.

Which primary structures make up the forebrain?

The forebrain consists of the Hypothalamus, Thalamus, Basal ganglia, Limbic system, and Cerebral Cortex.

What are the four lobes of the cerebral cortex shown in this diagram?

The four lobes of the cerebral cortex are the Frontal Lobe, Parietal Lobe, Occipital Lobe, and Temporal Lobe.

What is lateralization and contralateral representation in the cerebral cortex?

Lateralization is the dominance of one hemisphere in specific functions. Contralateral representation means the right hemisphere controls functions on the left side of the body and the left hemisphere controls functions on the right side.

What structure connects the two hemispheres of the brain?

The two hemispheres are connected by several bundles of fibers at their base, the largest of which is called the Corpus Colosseum (Corpus Callosum).

What functions are controlled by the frontal lobes and what occurs when the prefrontal association cortex is damaged?

The frontal lobes contain the primary motor cortex controlling voluntary movement and the prefrontal association cortex coordinating executive functions. Lesions here disrupt cognition and planning, causing decreased initiative, deficient self-awareness, and concreteness in thinking.

What functions are processed by the parietal lobes and what symptoms occur following injury?

The parietal lobes integrate vision, touch, and motor info (perception of space, object shape, orientation, actions, and numbers) and contain the somatosensory cortex (pressure, temperature, pain). Injury can cause acalculia and contralateral neglect.

What functions are controlled by the temporal lobes and what is auditory agnosia?

The temporal lobes are involved in receptive language, long-term memory, emotion, and contain the primary auditory cortex. Damage can cause auditory agnosia (inability to recognize the meaning of spoken words), selective attention deficits, hallucinations, delusions, and mood disturbance.

What are the visual effects of total destruction versus less extensive damage to the occipital lobes?

Total destruction of the occipital visual cortex in either hemisphere results in contralateral blindness. Less extensive damage produces image distortion, blindspots, persistent afterimages, loss of depth perception, and visual agnosia.

What are the distinct language functions of Broca's area and Wernicke's area shown in this cortex map?

Broca's area is vital for the formation of speech, whereas Wernicke's area interprets spoken and written language.

What ratio do glial cells have relative to neurons, and what are their primary functions?

Glial cells exist in a 1:1 ratio to neurons. Their functions are to support the nervous system, form the myelin sheath, form the blood-brain barrier to protect the brain, respond to injury, and remove debris.

What is resting potential and what is the specific electrical charge difference across the neural membrane?

Resting potential is the electrical charge difference across the neural membrane when the neuron has no active inputs; the inside of the cell is $-70\,\text{mV}$ more negative than the outside at rest.

What are the three steps involved in chemical neurotransmission between neurons?

1. Release of neurotransmitter from axon terminal into cleft. 2. Binding of neurotransmitter to receptor site on postsynaptic cell. 3. Halting the activity of the neurotransmitter via chemical breakdown or reuptake into the presynaptic axon terminal.

How many chromosomes do humans possess, and how do genotype and phenotype differ?

Humans have 46 chromosomes containing genes (DNA). Genotype is the set of genes inherited, while phenotype represents observable traits.

Who is pictured in this portrait, known as the Founder of Genetics?

Gregor Mendel.

How are natural selection and adaptations defined in genetics and evolutionary theory?

Natural selection (proposed by Charles Darwin) is the process where populations change by selective breeding with organisms possessing advantageous traits. Adaptations are physical or behavioral changes that make an organism better suited to its environment and ensure enhanced reproduction (fitness).

What is behavioral genetics and how is trait heritability defined?

Behavioral genetics examines the roles of nature and nurture in trait origins. Heritability is the extent to which genes contribute to differences in a trait among individuals in a population.

What is a potential confound in adoption studies conducted in behavioral genetics?

Selective placement.