Chapter 14 Study Questions - Spinal Cord & Spinal Nerves PDF

Below is a detailed and comprehensive response to the Chapter 14 Study Questions you provided. The answers are broken into sections and subsections according to the questions listed. Overview of Spinal Cord and Spinal Nerves 1. Describe the functions of the spinal cord and spinal nerves....

Below is a detailed and comprehensive response to the Chapter 14 Study Questions you provided. The answers are broken into sections and subsections according to the questions listed. Overview of Spinal Cord and Spinal Nerves 1. Describe the functions of the spinal cord and spinal nerves. ○ The spinal cord transmits sensory information from the body to the brain and motor commands from the brain to the body. It also coordinates reflexes, which are automatic responses to stimuli. ○ Spinal nerves connect the CNS to the peripheral body parts, allowing voluntary and involuntary control of muscles and communication with sensory organs. 2. What are the main regions of the spinal cord? ○ Cervical, thoracic, lumbar, sacral, and coccygeal regions. ○ Each region corresponds to a specific section of the vertebral column and controls specific parts of the body. 3. Describe the conus medullaris and cauda equina. ○ The conus medullaris is the tapered end of the spinal cord, located near L1-L2. ○ The cauda equina is a bundle of spinal nerve roots extending from the conus medullaris to the sacral and coccygeal regions, resembling a horse’s tail. 4. What is found in the white matter of the spinal cord? ○ Myelinated axons organized into tracts. ○ Function: Conduct nerve impulses for sensory and motor pathways between the brain and the body. 5. Identify and describe the posterior/dorsal root, posterior/dorsal root ganglion, and anterior/ventral root. ○ Posterior/dorsal root: Contains sensory fibers carrying information to the spinal cord. ○ Posterior/dorsal root ganglion: Houses sensory neuron cell bodies. ○ Anterior/ventral root: Contains motor fibers transmitting commands from the spinal cord to the muscles. 6. Are spinal nerves sensory, motor, or mixed nerves? ○ Mixed nerves, as they contain both sensory and motor fibers. 7. List the number of spinal nerves in each region of the spinal column. ○ Cervical: 8  ○ Thoracic: 12 ○ Lumbar: 5 ○ Sacral: 5 ○ Coccygeal: 1 Spinal Nerves 8. What does the dorsal/posterior ramus innervate? ○ The dorsal ramus innervates the muscles and skin of the back. 9. Which ramus is involved in plexuses? ○ The ventral ramus. 10. What is found in rami communicantes, the sympathetic trunk, and sympathetic trunk ganglion? ○ Rami communicantes: Sympathetic nerve fibers. ○ Sympathetic trunk: A chain of interconnected sympathetic ganglia. ○ Sympathetic trunk ganglion: Cell bodies of sympathetic neurons. 11. Define a dermatome. ○ A region of skin innervated by a single spinal nerve. 12. What is referred visceral pain? ○ Pain originating from internal organs but perceived as coming from a different area due to shared neural pathways. 13. Define a nerve plexus. ○ A network of interwoven spinal nerves. ○ Structures: Ventral rami of spinal nerves. ○ Advantage: Provides redundancy; if one nerve is damaged, others can compensate. ○ Regions: Cervical, brachial, lumbar, and sacral areas. 14. What structures do the intercostal nerves innervate? ○ They innervate intercostal muscles, abdominal wall muscles, and skin overlying these areas. 15. List the ventral rami that make up the cervical plexus. ○ C1-C4. ○ Region innervated: Neck, shoulder, and diaphragm. ○ Most important nerve: Phrenic nerve.  ○ Muscle innervated: Diaphragm. 16. List the ventral rami that make up the brachial plexus. ○ C5-T1. ○ Region innervated: Shoulder, arm, forearm, and hand. ○ Nerves: Axillary, musculocutaneous, radial, median, and ulnar. ○ Muscles: Deltoid (axillary), biceps brachii (musculocutaneous), triceps brachii (radial), forearm flexors (median/ulnar). 17. List the ventral rami that make up the lumbar plexus. ○ L1-L4. ○ Region innervated: Abdominal wall, anterior thigh, and medial thigh. ○ Nerves: Femoral and obturator. ○ Muscles: Quadriceps (femoral) and adductors (obturator). 18. List the ventral rami that make up the sacral plexus. ○ L4-S4. ○ Region innervated: Pelvis, posterior thigh, leg, and foot. ○ Sciatic nerve: Largest nerve, splits into the tibial and common fibular nerves. ○ Muscles: Hamstrings, gastrocnemius (tibial), and tibialis anterior (fibular). Protection and Support of the Spinal Cord 19. List the meninges in order. ○ Superficial to deep: Dura mater, arachnoid mater, pia mater. ○ Deep to superficial: Pia mater, arachnoid mater, dura mater. 20. Describe the pia mater, arachnoid mater, and dura mater. ○ Pia mater: Thin, vascular membrane attached to the spinal cord. ○ Arachnoid mater: Web-like middle layer. ○ Dura mater: Tough, outermost layer. 21. Describe the location of the epidural space, subdural space, and subarachnoid space. ○ Epidural space: Between dura mater and vertebrae; contains fat. ○ Subdural space: Between dura mater and arachnoid mater. ○ Subarachnoid space: Between arachnoid and pia mater; contains CSF. 22. Where is cerebrospinal fluid found? ○ Subarachnoid space and central canal.  23. Functions of the filum terminale and denticulate ligament? ○ Filum terminale: Anchors spinal cord to coccyx. ○ Denticulate ligaments: Stabilize spinal cord laterally. Sectional Anatomy of the Spinal Cord and Spinal Roots 24. Define nucleus (in CNS). ○ A cluster of neuron cell bodies within the CNS. 25. What structures are found in the gray matter of the spinal cord? ○ Cell bodies, dendrites, and unmyelinated axons. 26. What is found in the anterior/ventral horns? ○ Somatic motor neuron cell bodies. ○ Function: Motor output to skeletal muscles. 27. What is found in the lateral horns? ○ Autonomic motor neuron cell bodies. ○ Function: Motor control of visceral organs. ○ Regions: Thoracic and upper lumbar. 28. What is found in the posterior/dorsal horns? ○ Interneurons and sensory neuron axons. ○ Function: Process sensory input. 29. What is the function of the gray commissure? ○ Connects the two sides of the spinal cord. 30. What is found in the central canal? ○ CSF. 31. What is found in the white matter of the spinal cord? ○ Myelinated axons organized into tracts. ○ Tract: A bundle of axons in the CNS. ○ Divisions: Posterior, lateral, and anterior funiculi. 32. Direction of sensory (ascending) tracts? ○ Toward the brain. 33. Direction of motor (descending) tracts?  ○ Away from the brain. Would you like the Sensory and Motor Pathways and Reflexes sections answered as well? Let me know!