All flashcards
Flashcard 1: What is the primary function of the autonomic nervous system (ANS)?
Answer: Involuntary regulation of glands, smooth and cardiac muscle. ANS operates without conscious control for internal organ function.
Flashcard 2: Identify the neurotransmitter released by most sympathetic postganglionic neurons.
Answer: Norepinephrine. NE binds adrenergic receptors for sympathetic effects.
Flashcard 3: Which ion efflux primarily causes repolarization during a neuronal action potential?
Answer: Potassium (K+) efflux. Opens after Na+ channels to restore negative potential.
Flashcard 4: What is the term for the myelin-producing cell type in the PNS?
Answer: Schwann cell. Forms myelin sheaths around PNS axons for faster conduction.
Flashcard 5: What is the term for the myelin-producing cell type in the CNS?
Answer: Oligodendrocyte. Forms myelin sheaths around CNS axons for faster conduction.
Flashcard 6: Which hypothalamic–pituitary–adrenal (HPA) axis hormone directly stimulates cortisol release?
Answer: ACTH (adrenocorticotropic hormone). Released by anterior pituitary to stimulate adrenal cortex.
Flashcard 7: Which ANS division mediates “rest-and-digest” functions?
Answer: Parasympathetic nervous system. Promotes energy conservation and digestion when relaxed.
Flashcard 8: Which ANS division mediates the “fight-or-flight” response?
Answer: Sympathetic nervous system. Activates during stress to prepare body for action.
Flashcard 9: What are the three major parts of a neuron?
Answer: Dendrites, soma (cell body), axon. These structures process, integrate, and transmit neural signals.
Flashcard 10: What is the role of the myelin sheath in neural signaling?
Answer: Increases conduction velocity by insulating the axon. Prevents ion leakage and speeds signal propagation.
Flashcard 11: What is an excitatory postsynaptic potential (EPSP)?
Answer: Postsynaptic depolarization that increases firing likelihood. Makes membrane potential less negative, closer to threshold.
Flashcard 12: What type of feedback loop most commonly regulates endocrine hormone levels?
Answer: Negative feedback. High hormone levels inhibit further release for homeostasis.
Flashcard 13: Which glial cells form myelin in the peripheral nervous system?
Answer: Schwann cells. Each wraps one PNS axon segment with myelin.
Flashcard 14: What is the all-or-none principle of action potentials?
Answer: If threshold is reached, firing occurs at full amplitude. No partial action potentials exist - it's binary.
Flashcard 15: What is the primary function of the somatic nervous system (SNS)?
Answer: Voluntary control of skeletal muscles; sensory to CNS. SNS controls conscious movements and relays sensory information.
Flashcard 16: Which ANS division is classically described as “rest-and-digest”?
Answer: Parasympathetic nervous system. Promotes energy conservation and digestion when relaxed.
Flashcard 17: Which ion’s influx primarily causes the depolarization phase of an action potential?
Answer: Na+ influx. Voltage-gated Na+ channels open, making membrane potential positive.
Flashcard 18: What is the primary function of a neuron's axon?
Answer: Conduct action potentials away from the soma to terminals. Axons are output structures carrying signals to other neurons.
Flashcard 19: What is the primary function of a neuron's dendrites?
Answer: Receive synaptic input and conduct signals toward the soma. Dendrites are the input structures that transmit signals inward.
Flashcard 20: Identify the endocrine gland that secretes insulin and glucagon to regulate blood glucose.
Answer: Pancreas (islets of Langerhans). Beta cells release insulin; alpha cells release glucagon.
Flashcard 21: Which adrenal hormone is the main long-term stress hormone that increases blood glucose?
Answer: Cortisol (from adrenal cortex). Glucocorticoid that mobilizes glucose during chronic stress.
Flashcard 22: Which hormone from the posterior pituitary primarily increases water reabsorption in the kidneys?
Answer: Antidiuretic hormone (ADH, vasopressin). ADH acts on collecting ducts to concentrate urine.
Flashcard 23: Which brain structure is the major relay station for sensory information to the cortex?
Answer: Thalamus. All senses except smell pass through thalamus first.
Flashcard 24: What is the primary role of the parasympathetic nervous system?
Answer: Rest-and-digest: conserves energy and promotes maintenance functions. Uses acetylcholine to slow heart rate and promote digestion.
Flashcard 25: What is the primary role of the sympathetic nervous system?
Answer: Fight-or-flight: mobilizes energy and increases arousal. Releases norepinephrine/epinephrine for stress response.
Flashcard 26: Which neurotransmitter is classically decreased in Parkinson disease?
Answer: Dopamine. Loss of dopaminergic neurons in substantia nigra causes symptoms.
Flashcard 27: What is the correct order of information flow in a basic reflex arc?
Answer: Receptor → sensory neuron → interneuron → motor neuron → effector. Shows the complete pathway from stimulus to response.
Flashcard 28: Which ANS division is classically described as “fight-or-flight”?
Answer: Sympathetic nervous system. Activates during stress for rapid energy mobilization.
Flashcard 29: What is the immediate effect of parasympathetic activation on gastrointestinal motility?
Answer: Increases gastrointestinal motility and secretion. Enhances digestion when body is at rest.
Flashcard 30: What is the immediate effect of sympathetic activation on heart rate?
Answer: Increases heart rate. Prepares body for action by increasing cardiac output.