Chapter 13 Flashcards
What are the two main divisions of the nervous system?
Central Nervous System (CNS) and Peripheral Nervous System (PNS).
What structures make up the CNS?
The brain and spinal cord.
What structures make up the PNS?
Cranial nerves and spinal nerves.
What does the autonomic nervous system (ANS) control?
Involuntary functions, like heart rate, digestion, and respiratory rate.
What are the two divisions of the ANS?
Sympathetic and parasympathetic divisions.
What is the function of the sympathetic division of the ANS?
Prepares the body for “fight or flight” responses.
What is the function of the parasympathetic division of the ANS?
Promotes “rest and digest” activities.
What are the three main parts of a neuron?
Cell body (soma), dendrites, and axon.
What is the function of dendrites?
Receive signals from other neurons and transmit them to the cell body.
What is the function of the axon?
Transmits electrical impulses away from the cell body.
How are neurons classified structurally?
Multipolar, bipolar, unipolar, and anaxonic.
How are neurons classified functionally?
Sensory (afferent), motor (efferent), and interneurons.
What is myelin?
A lipid-rich substance that insulates axons and increases the speed of impulse transmission.
Which cells produce myelin in the CNS?
Oligodendrocytes.
Which cells produce myelin in the PNS?
Schwann cells.
What is the function of astrocytes?
Maintain the blood-brain barrier, provide structural support, and regulate ion concentrations.
What do ependymal cells do?
Line the ventricles of the brain and the central canal of the spinal cord; produce and circulate cerebrospinal fluid (CSF).
What is the role of microglia?
Act as immune cells in the CNS, cleaning up debris and pathogens through phagocytosis.
What is the main function of Schwann cells?
Produce myelin in the PNS and assist in nerve regeneration.
What do satellite cells do in the PNS?
Surround neuron cell bodies and regulate the environment around them.
What are mechanoreceptors?
Receptors that detect mechanical stimuli, such as touch, pressure, and vibration.
What are nociceptors?
Receptors that detect pain.
What are the main functions of the spinal cord?
Conducts sensory and motor information and integrates reflexes.
How is the spinal cord organized regionally?
Into cervical, thoracic, lumbar, sacral, and coccygeal regions.
What does the dorsal root of a spinal nerve contain?
Sensory (afferent) nerve fibers.
What does the ventral root of a spinal nerve contain?
Motor (efferent) nerve fibers.
What are the three layers of the spinal meninges?
Dura mater, arachnoid mater, and pia mater.
What is the dura mater?
The tough, outermost layer of the meninges.
What is the pia mater?
The delicate, innermost layer of the meninges that adheres to the surface of the spinal cord.
What is the conus medullaris?
The tapered, conical end of the spinal cord.
What is the cauda equina?
A bundle of spinal nerves and nerve roots extending from the conus medullaris.
What is the filum terminale?
A fibrous extension of the pia mater that anchors the spinal cord to the coccyx.
What is the function of the denticulate ligament?
To anchor the spinal cord laterally to the dura mater, providing stability.
What is the coccygeal ligament?
A structure formed by the fusion of the filum terminale and dura mater, anchoring the spinal cord to the coccyx.
What are spinal nerves composed of?
Both sensory and motor nerve fibers.
What are sensory (afferent) pathways?
Pathways that transmit sensory information from the body to the brain.
What are motor (efferent) pathways?
Pathways that transmit motor commands from the brain to the body.
What is the dorsal column-medial lemniscal pathway?
A sensory pathway that transmits information about fine touch, pressure, and proprioception to the brain.
What is the spinothalamic pathway responsible for?
Transmitting pain, temperature, and crude touch sensations to the brain.
What is the function of the corticospinal tract?
To carry motor signals from the cerebral cortex to the spinal cord, controlling voluntary movements.
What are vesicular synapses?
Synapses where neurotransmitters are released from vesicles into the synaptic cleft.
What is a common neurotransmitter at vesicular synapses?
Acetylcholine.
What are electrical synapses?
Synapses where electrical signals are directly transmitted between neurons through gap junctions.
Why are electrical synapses faster than chemical synapses?
Because they allow direct electrical communication without the need for neurotransmitters.
What are the main differences between the dorsal and ventral roots of spinal nerves?
Dorsal roots carry sensory information into the spinal cord, while ventral roots carry motor information out to the body.
What is the significance of the spinal meninges?
They protect and stabilize the spinal cord and contain cerebrospinal fluid (CSF) for cushioning.
What type of information does the lateral spinothalamic tract carry?
Pain and temperature sensations.
What is the role of proprioceptors?
To detect body position and movement, providing feedback to the brain about joint angles and muscle length.
Where is cerebrospinal fluid (CSF) found in the spinal meninges?
In the subarachnoid space, between the arachnoid mater and pia mater.
What is the role of the autonomic nervous system in controlling internal organs?
It regulates involuntary functions such as heart rate, digestion, and respiratory rate through the sympathetic and parasympathetic divisions.
