1.
The end of the spinal cord is called ________.
Correct Answer
A. Conus Medullaris
Explanation
The end of the spinal cord is called the Conus Medullaris. This is the tapered, cone-shaped structure that marks the termination of the spinal cord in the lumbar region. It is located at the level of the first or second lumbar vertebra. The Conus Medullaris is an important anatomical landmark and is involved in the transmission of sensory and motor signals between the spinal cord and the lower extremities.
2.
Axons extending posteriorly from the SC and continues within the vertebral foramen.
Correct Answer
Cauda equina
Explanation
The cauda equina refers to a bundle of nerves located at the lower end of the spinal cord. It is formed by the continuation of axons that extend posteriorly from the spinal cord and pass through the vertebral foramen. These axons are responsible for transmitting sensory and motor signals to and from the lower limbs and pelvic organs. Therefore, the given statement correctly describes the cauda equina as the structure where the axons from the spinal cord extend and continue within the vertebral foramen.
3.
Extension of the pia mater that connects to the coccyx; suspends the SC superior-inferior
Correct Answer
Filum terminale
Explanation
The filum terminale is an extension of the pia mater that connects to the coccyx. It acts as a suspension for the spinal cord, helping to hold it in place within the vertebral canal. This structure is important for providing stability and support to the spinal cord, allowing it to move and function properly.
4.
Lateral ligaments that prevent SC movement laterally
Correct Answer
Denticulate ligaments
Explanation
The denticulate ligaments are a series of delicate membranous structures that extend laterally from the spinal cord and attach it to the dura mater. These ligaments help to stabilize the spinal cord within the vertebral canal and prevent excessive lateral movement. Therefore, the denticulate ligaments serve as lateral ligaments that prevent the spinal cord from moving laterally.
5.
Horns are connected by the ________.
Correct Answer
Grey commisure
Explanation
The grey commissure is a structure in the spinal cord that connects the two halves of the grey matter. Grey matter is responsible for processing and transmitting information in the spinal cord. Therefore, horns, which are extensions of the grey matter, are connected by the grey commissure.
6.
What flows through central canal?
Correct Answer
C. CSF
Explanation
The central canal is a narrow channel that runs through the center of the spinal cord and contains cerebrospinal fluid (CSF). CSF is a clear, colorless fluid that surrounds and protects the brain and spinal cord. It acts as a cushion, providing support and nutrients to the nervous tissue, as well as removing waste products. Therefore, CSF is the correct answer for what flows through the central canal.
7.
Lateral spinal nerve branches are mixed nerves called ________.
Correct Answer
Rami
Explanation
Lateral spinal nerve branches are mixed nerves called rami. Rami are the branches of spinal nerves that carry both sensory and motor fibers. They are responsible for transmitting information between the spinal cord and various parts of the body. These branches are named based on their location and function, such as dorsal rami (supplying the back muscles) and ventral rami (supplying the front and sides of the body). Therefore, rami accurately describe the lateral spinal nerve branches as mixed nerves.
8.
What is the 'bump' on the dorsal root ganglion?
Correct Answer
A cluster of cell bodies in the PNS
Explanation
The 'bump' on the dorsal root ganglion refers to a cluster of cell bodies located in the peripheral nervous system (PNS). The dorsal root ganglion is a structure found along the spinal cord, and it contains the cell bodies of sensory neurons. These sensory neurons receive information from the body's periphery and transmit it to the central nervous system. Therefore, the bump on the dorsal root ganglion represents a collection of cell bodies responsible for relaying sensory information from the body to the spinal cord.
9.
What is a group of axons and other neuron parts that conduct APs bodywide on the dorsal rami?
Correct Answer
Sympathetic chain
Explanation
The sympathetic chain is a group of axons and other neuron parts that conduct action potentials (APs) bodywide on the dorsal rami. The sympathetic chain is a part of the sympathetic nervous system, which is responsible for the "fight or flight" response in the body. This chain plays a crucial role in transmitting signals from the spinal cord to various organs and tissues throughout the body, allowing for coordinated physiological responses to stress or danger.
10.
Each axon is covered by a(n) _______.
Correct Answer
Endoneurium
Explanation
Each axon is covered by a protective layer called the endoneurium. This layer surrounds and supports the axon, providing insulation and maintaining the integrity of the nerve fiber. It helps to protect the axon from damage and allows for efficient transmission of electrical signals along the nerve.
11.
Groups of fascicles form a nerve, which is covered by ______ (thin collagen fiber layer).
Correct Answer
Epineurium
Explanation
The correct answer is "Epineurium." The epineurium is a thin collagen fiber layer that surrounds and protects the nerve. It provides structural support and helps maintain the integrity of the nerve.
12.
Nerves come in 3 types:
Correct Answer
D. Sensory, motor, mixed
Explanation
The correct answer is "Sensory, motor, mixed" because these are the three types of nerves found in the human body. Sensory nerves transmit information from the sensory organs to the brain, allowing us to perceive and interpret the external world. Motor nerves, on the other hand, carry signals from the brain to the muscles, enabling voluntary movements. Mixed nerves contain both sensory and motor fibers, allowing for two-way communication between the brain and the body. Therefore, this answer accurately represents the different types of nerves.
13.
What is a nerve plexus?
Correct Answer
Group of spinal nerves
Explanation
A nerve plexus refers to a group of spinal nerves that come together and then branch out to form a network. These networks are responsible for distributing nerve signals to specific regions of the body. Each nerve plexus serves a different area and is responsible for controlling various motor and sensory functions. The spinal nerves within a plexus work together to transmit signals and ensure proper communication between the central nervous system and the specific body parts associated with that plexus.
14.
Notation that nerves serving a joint also branch to serve muscles surrounding the joint.
Correct Answer
Hilton's law
Explanation
Hilton's law states that the nerves serving a joint also branch out to serve the muscles surrounding that joint. This means that the nerves that provide sensory information from the joint also innervate the muscles that move and stabilize the joint. This is important for coordinating movement and providing feedback about joint position and movement to the brain. Hilton's law helps to explain the close relationship between the nerves, joints, and muscles in the body.
15.
Name the 4 types of nerve plexus.
Correct Answer
Cervical, brachial, lumbar, sacral
Explanation
The four types of nerve plexus are cervical, brachial, lumbar, and sacral. These nerve plexuses are formed by the branching and intermingling of nerves from different spinal segments. The cervical plexus is located in the neck region and supplies nerves to the head, neck, and upper shoulders. The brachial plexus is found in the shoulder region and innervates the upper limbs. The lumbar plexus is situated in the lower back and provides nerves to the lower abdomen and thighs. Lastly, the sacral plexus is located in the pelvis and supplies nerves to the buttocks, lower limbs, and pelvic organs.
16.
What fiber type does olfactory nerve have?
Correct Answer
A. Sensory
Explanation
The olfactory nerve is responsible for transmitting sensory information related to the sense of smell from the nasal cavity to the brain. It does not have any motor functions, meaning it does not control any muscles or movement. Therefore, the correct answer is sensory.
17.
Optic nerve
Correct Answer
A. Sensory
Explanation
The optic nerve is responsible for transmitting visual information from the eye to the brain. It is composed of sensory fibers that carry visual signals, allowing us to see and perceive our surroundings. Therefore, the correct answer is sensory.
18.
Oculomotor nerve
Correct Answer
B. Motor
Explanation
The oculomotor nerve is responsible for the motor function of the eye muscles. It controls the movement of the eyeball and helps with functions such as raising the eyelid and adjusting the size of the pupil. Therefore, the correct answer is "Motor" as it accurately describes the role of the oculomotor nerve in controlling the motor functions of the eye.
19.
Trochlear nerve
Correct Answer
B. Motor
Explanation
The trochlear nerve is responsible for motor function. It is the fourth cranial nerve and is the only nerve that emerges from the dorsal side of the brainstem. It controls the movement of the superior oblique muscle of the eye, which helps in downward and outward eye movement. This motor function allows for coordinated eye movements and helps maintain proper alignment and visual tracking.
20.
Trigeminal nerve
Correct Answer
C. Mixed
Explanation
The trigeminal nerve is a cranial nerve that contains both sensory and motor fibers. It provides sensory information from the face, including touch, pain, and temperature sensations, to the brain. Additionally, it controls the muscles involved in chewing and jaw movement. Therefore, the trigeminal nerve is considered a mixed nerve because it carries both sensory and motor signals.
21.
Abducens nerve
Correct Answer
B. Motor
Explanation
The abducens nerve is responsible for controlling the movement of the lateral rectus muscle, which is involved in the abduction of the eye (outward movement). This indicates that the abducens nerve is primarily involved in motor function, as it controls the movement of a specific muscle.
22.
Facial nerve
Correct Answer
C. Mixed
Explanation
The facial nerve is classified as mixed because it contains both sensory and motor fibers. Sensory fibers of the facial nerve are responsible for transmitting sensations from the taste buds on the anterior two-thirds of the tongue, while motor fibers innervate the muscles of facial expression, including those involved in smiling, frowning, and closing the eyes. Therefore, the facial nerve serves both sensory and motor functions, making it a mixed nerve.
23.
Vestibulocochlear nerve
Correct Answer
A. Sensory
Explanation
The vestibulocochlear nerve is responsible for transmitting sensory information from the inner ear to the brain. It is involved in hearing and balance. As a sensory nerve, it does not have any motor function.
24.
Glossopharyngeal nerve
Correct Answer
C. Mixed
Explanation
The glossopharyngeal nerve is classified as mixed because it contains both sensory and motor fibers. Sensory fibers of this nerve are responsible for transmitting information from the tongue, throat, and the back of the throat to the brain. Motor fibers, on the other hand, control the movement of certain muscles in the throat, including those involved in swallowing and speech production. Therefore, the glossopharyngeal nerve serves both sensory and motor functions, making it a mixed nerve.
25.
Vagus nerve
Correct Answer
C. Mixed
Explanation
The vagus nerve is classified as mixed because it contains both sensory and motor fibers. Sensory fibers transmit information from various organs in the body, such as the heart, lungs, and digestive system, to the brain. Motor fibers, on the other hand, carry signals from the brain to control muscles involved in functions like swallowing and speaking. The mixed nature of the vagus nerve allows for bidirectional communication between the brain and different organs, enabling regulation of various bodily functions.
26.
Accessory nerve
Correct Answer
B. Motor
Explanation
The accessory nerve is classified as a motor nerve. This means that its primary function is to control the movement of muscles. Unlike sensory nerves, which transmit sensory information from the body to the brain, and mixed nerves, which have both sensory and motor functions, the accessory nerve specifically controls motor functions.
27.
Hypoglossal nerve
Correct Answer
B. Motor
Explanation
The hypoglossal nerve is primarily responsible for motor functions. It innervates the muscles of the tongue, allowing for movement and control of the tongue during speech, swallowing, and chewing. It does not have a significant sensory component, meaning it does not play a major role in transmitting sensory information. Therefore, the correct answer is motor.