Nervous System Organization

Central nervous system (CNS) and peripheral nervous system (PNS)

The CNS processes incoming sensory information and serves as the source of thoughts, emotions, and memories. It also sends signals that stimulate muscle contraction and gland secretion.

The spinal cord connects the brain to the rest of the body and is responsible for transmitting sensory information to the brain and motor signals from the brain to the muscles and glands.

<p>Afferent division and efferent division</p> Signup and view all the answers

<p>Nerves are bundles of axons that lie outside the brain and spinal cord.</p> Signup and view all the answers

<p>Sensory receptors monitor changes in the external or internal environment.</p> Signup and view all the answers

<p>The afferent division carries sensory information from the body to the CNS.</p> Signup and view all the answers

<p>Tactile (touch), thermal (temperature), pain, and proprioceptive (position and movement of joints) sensations</p> Signup and view all the answers

<p>Smell, taste, vision, hearing, and equilibrium</p> Signup and view all the answers

<p>Somatic nervous system and autonomic nervous system</p> Signup and view all the answers

<p>The somatic nervous system controls voluntary movements of skeletal muscles.</p> Signup and view all the answers

<p>The autonomic nervous system controls involuntary actions of smooth muscles, cardiac muscles, and glands.</p> Signup and view all the answers

<p>Parasympathetic nervous system, sympathetic nervous system, and enteric nervous system</p> Signup and view all the answers

<p>They have opposite effects on the body.</p> Signup and view all the answers

<p>The sympathetic nervous system increases heart rate, while the parasympathetic nervous system slows down the heart rate.</p> Signup and view all the answers

<p>Sensory function, integrative function, and motor function</p> Signup and view all the answers

<p>Sensory neurons transmit action potentials from sensory receptors to the CNS.</p> Signup and view all the answers

<p>Interneurons process information from sensory neurons and activate appropriate motor neurons.</p> Signup and view all the answers

<p>Neuroglia are supporting cells that nourish, protect, and maintain homeostasis for neurons.</p> Signup and view all the answers

<p>They are essential for the proper functioning of neurons and the nervous system as a whole.</p> Signup and view all the answers

<p>Astrocytes are the most abundant type of neuroglia in the CNS and they perform a variety of functions, including supporting and nourishing neurons.</p> Signup and view all the answers

<p>Astrocytes secrete chemicals that maintain the tightness of tight junctions in the blood-brain barrier, isolating neurons in the CNS from harmful substances.</p> Signup and view all the answers

<p>Oligodendrocytes form and maintain the myelin sheath around axons in the CNS.</p> Signup and view all the answers

<p>Microglia are the phagocytic cells of the CNS that remove cellular debris and pathogens.</p> Signup and view all the answers

<p>Ependymal cells line the ventricles of the brain and central canal of the spinal cord, producing and circulating cerebrospinal fluid.</p> Signup and view all the answers

<p>Schwann cells form and maintain the myelin sheath around axons in the PNS.</p> Signup and view all the answers

<p>The myelin sheath is a multilayer covering of lipids and proteins that insulates axons.</p> Signup and view all the answers

<p>Myelination is the process of forming the myelin sheath around axons.</p> Signup and view all the answers

<p>In the PNS, one Schwann cell wraps around one segment of an axon, whereas in the CNS, one oligodendrocyte can wrap around multiple axons.</p> Signup and view all the answers

<p>White matter is mainly composed of myelinated axons, while gray matter is composed of cell bodies, dendrites, unmyelinated axons, axon terminals, and neuroglia.</p> Signup and view all the answers

<p>Neurons and muscle fibers communicate through electrical signals, including graded potentials and action potentials.</p> Signup and view all the answers

<p>Action potentials cause neurons to release neurotransmitters and muscle fibers to contract.</p> Signup and view all the answers

<p>Sensory information is processed through a series of steps, starting with a graded potential in the sensory receptor, then an action potential traveling along the sensory neuron to the CNS, followed by activation of interneurons in the CNS, and finally interpretation of the stimuli in the cerebral cortex.</p> Signup and view all the answers

<p>A stimuli in the brain leads to the generation of action potentials in upper motor neurons, which then activate lower motor neurons. The action potentials in lower motor neurons release neurotransmitters at the neuromuscular junction, causing skeletal muscle contraction and a motor response.</p> Signup and view all the answers

<p>The presence of specific ion channels and the existence of resting membrane potential</p> Signup and view all the answers

<p>Ion channels allow ions to move across the cell membrane, creating a flow of electrical current that changes the membrane potential.</p> Signup and view all the answers

<p>Leak channels are always open and allow for a continuous flow of ions, ligand-gated channels open in response to the binding of a specific ligand, and voltage-gated channels open in response to changes in membrane potential.</p> Signup and view all the answers

<p>Resting membrane potential is the electrical charge difference across the cell membrane when the cell is at rest.</p> Signup and view all the answers