Chapter 2 notes – the nervous system (Video)

Flashcards covering CNS/PNS, neuron structure and function, neural transmission, neurotransmitters, brain regions and functions, hemispheric specialization, and the endocrine system.

What are the two main components of the Peripheral Nervous System (PNS)?

The Somatic Nervous System and the Autonomic Nervous System.

What does the Somatic Nervous System control?

Voluntary muscles and it transmits sensory information to the CNS.

What does the Autonomic Nervous System control?

Involuntary body functions.

What are the two branches of the Autonomic Nervous System and what does each do?

Sympathetic nervous system arouses the body to expend energy; Parasympathetic nervous system calms the body to conserve energy.

What are the major components of a neuron?

Cell body (soma), dendrites, axon, and axon terminals (buttons).

What is the function of the cell body (soma)?

Manufactures proteins and nutrients; contains the nucleus with DNA.

What is the function of the axon?

Carries information to other cells.

What do sensory neurons do?

Convey information about light or sound to the brain.

What do motor neurons do?

Convey information to the muscles and glands."

What are interneurons?

Communicate information between neurons; the most numerous in the nervous system.

What are dendrites?

Branches that receive messages from other neurons and specialized cells.

What are axon terminals?

Transmit information (neurotransmitters) to other neurons.

What is the myelin sheath?

A white fatty covering around some axons that increases communication speed.

What is an action potential?

A brief electrical impulse by which information is transmitted along the axon.

What is the stimulus threshold?

The minimum level of stimulation required to activate a neuron.

What is resting potential?

The state in which a neuron is prepared to activate if it receives sufficient stimulation.

What are ions?

Atoms or molecules with unequal numbers of electrons and protons, giving them a net positive or negative charge.

What happens during an action potential in terms of ions?

Sodium and potassium ions move across the membrane; the interior becomes briefly positive.

What is the all-or-nothing law in neurons?

Once an action potential starts, it travels the length of the axon; there are no partial action potentials.

What is the refractory period?

The period immediately after an action potential when a neuron cannot fire again, allowing repolarization.

What is a synapse?

The junction between a presynaptic and a postsynaptic neuron where communication occurs.

What is the synaptic gap?

The tiny fluid-filled space between neurons.

How can neurons communicate between neurons?

chemically via neurotransmitters or electrically.

What are synaptic vesicles?

Tiny sacs in axon terminals that hold neurotransmitters.

What are neurotransmitters?

Chemical messengers released into the synaptic gap to bind to receptors on other neurons.

What is reuptake?

Neurotransmitter molecules are reabsorbed by the presynaptic neuron for reuse.

What is dopamine associated with?

Movement, attention, learning, and pleasurable/reward sensations; linked to addiction.

What is acetylcholine?

A neurotransmitter in all motor neurons; important for learning and intellect; deficits linked to Alzheimer's; involved in Parkinson’s through dopamine interactions.

What is serotonin?

Neurotransmitter involved in sleep, mood, and sensory perceptions; antidepressants often inhibit its reuptake.

What is GABA?

Gamma-aminobutyric acid; an inhibitory neurotransmitter balancing excitatory signals; increased by anti-anxiety drugs.

What is norepinephrine?

Helps gear the body for danger (fight/flight); also regulates sleep, learning, and memory retrieval; linked to depression when dysfunctional.

What are endorphins?

The body's natural pain relief system; also produces feelings of well-being.

What is an agonist in neurotransmission?

A chemical that resembles a neurotransmitter and can occupy its receptor sites (e.g., nicotine mimicking acetylcholine).

What is an antagonist in neurotransmission?

A chemical that blocks a neurotransmitter’s receptor sites (e.g., naloxone blocks opioid receptors).

What is the Central Nervous System (CNS)?

The brain and the spinal cord.

What is the brainstem composed of and what is its role?

Hindbrain and midbrain; basic life-support functions and reflexes; contralateral organization.

What are the key parts of the hindbrain and their functions?

Medulla (autonomic functions, reflexes), Pons (relay information and breathing regulation), Cerebellum (balance and coordination). Reticular Formation regulates attention and sleep.

What is the limbic system?

A border region around the brainstem involved in motivations, emotions, and memory.

Name some structures of the limbic system and their roles.

Hippocampus (memory formation), Thalamus (sensory relay and awareness), Hypothalamus (autonomic regulation, eating/drinking, fear, aggression; influences the pituitary), Amygdala (emotional responses and goal-directed behavior).

What is neurogenesis?

The development of new neurons, occurring in the hippocampus throughout life.

What are the four lobes of the cerebral cortex and their principal functions?

Temporal (auditory processing), Occipital (visual processing), Parietal (somatosensory processing), Frontal (planning, initiating, executing movements).

What is the corpus callosum?

A thick band of axons that connects the two cerebral hemispheres.

What are Broca’s and Wernicke’s areas?

Broca’s area (left frontal lobe) controls speech production; Wernicke’s area (left temporal lobe) controls speech comprehension.

What is lateralization of function?

Left hemisphere is typically dominant for language; right hemisphere more involved in nonverbal, spatial, and emotional processing.

What is a split-brain procedure and what has it taught us?

Surgical cutting of the corpus callosum to treat seizures; revealed hemispheric specialization, especially language being left-hemisphere dominant.

What is sensation?

The process of detecting physical stimuli from the environment.

What is the endocrine system?

A network of glands throughout the body that secrete hormones.

What does the pineal gland do?

Produces melatonin, regulating sleep-wake cycles.

What does the hypothalamus do in the endocrine system?

Regulates the pituitary gland and links the nervous system to the endocrine system; controls autonomic functions, hunger, thirst, temperature, and aggression.

What does the pituitary gland do?

Regulates activities of several other glands; produces growth hormone, prolactin, oxytocin.

What do the thyroid, adrenal glands, pancreas, ovaries, and testes do?

Thyroid: metabolism; Adrenal glands: epinephrine and norepinephrine (arousal); Pancreas: blood sugar and insulin; Ovaries: estrogen/progesterone; Testes: testosterone.