Anatomy & Physiology Nervous System and Vertebral Column Study Guide
Terms in this set (28)
The nervous system controls sensory input, integration, and motor output.
The nervous system is divided into the CNS (central nervous system) and PNS (peripheral nervous system), with PNS subdivided into sensory and motor components.
Sensory neurons carry impulses to the CNS; motor neurons carry impulses away from the CNS to effectors.
Somatic controls voluntary movements; visceral controls involuntary functions of organs.
Afferent pathways carry signals toward the CNS; efferent pathways carry signals away from the CNS.
Neuroglia support neurons by providing protection, nutrients, and myelination.
Neurons have a cell body, dendrites (receive signals), and an axon (sends signals).
Myelin insulates axons to speed signal conduction; formed by Schwann cells in PNS and oligodendrocytes in CNS.
Gaps in the myelin sheath where ion channels are concentrated to facilitate rapid signal conduction.
Neurons are classified as multipolar, bipolar, or unipolar based on the number of processes.
Neurons are classified as sensory, motor, or interneurons based on function.
The voltage difference across the membrane at rest, typically around \(-70\,mV\), maintained by ion gradients and permeability.
Resting potential is maintained by the Na+/K+ pump and differential membrane permeability to ions.
Graded potentials vary in magnitude and decay with distance; action potentials are all-or-none signals that propagate without decrement.
Phases include depolarization, repolarization, and hyperpolarization, involving opening and closing of voltage-gated Na+ and K+ channels.
Action potentials propagate along the axon by sequential opening of voltage-gated channels, enabling signal transmission.
Absolute refractory period: no new action potential possible; relative refractory period: a stronger stimulus can trigger an action potential.
Synapses transmit signals between neurons via chemical neurotransmitters or electrical coupling.
Excitatory potentials depolarize the membrane; inhibitory potentials hyperpolarize it, affecting neuron firing.
Postsynaptic potentials combine spatially and temporally to influence whether an action potential is generated.
Acetylcholine mediates synaptic transmission at neuromuscular junctions and in the autonomic nervous system.
Frontal: motor control; parietal: sensory processing; occipital: vision; temporal: auditory; insula: visceral sensation.
The cerebral cortex is the brain's outer layer responsible for conscious thought, sensory perception, and motor commands.
Association fibers connect areas within the same hemisphere; commissural fibers connect hemispheres; projection fibers connect cortex to lower brain regions.
Sensory information typically flows from receptors to the primary sensory cortex, then to association areas for processing.
Motor commands originate in the primary motor cortex, then travel through descending pathways to muscles.
Male pelves are generally narrower and taller; female pelves are wider and shallower to facilitate childbirth.
Abnormal curvatures include scoliosis, kyphosis, and lordosis, affecting posture and spinal function.