Lab Manual of regional anatomy for student
BACK
Assignments:
1. Complete the learning module entitled anatomy and imaging.
2. Complete the learning module entitled back.
Objectives:
1. Define the "anatomical position". Using the conventional anatomical terms, describe the
body and the spatial relationships of its parts, for example dorsal/ventral, medial/lateral,
proximal/distal, and superficial/deep.
2. Recognize and define the standard planes and sections used to describe parts of the body
and the relationships of the various planes and sections to one another.
3. Describe the general structural plan of the body and the relationships of the layers,
partitions and compartments one encounters when dissecting from superficial to deep in
any particular region.
4. Identify the layers of back; define the “triangle of auscultation”, “upper lumbar triangle”,
and “lower lumbar triangle”.
5. Describe the blood supply and innervations of the back.
6. Describe the construction of the vertebral column.
7. Recognize the anatomical structures related to lumbar puncture.
8. Identify the coverings of the spinal cord and the spinal meninges.
9. Describe the blood supply of the spinal cord.
Procedure:
1. Study laboratory 1 and 2 (human anatomy).
2. Study figures 142-166 (interactive atlas).
3. Discuss the next questions in groups
1). Discuss the clinical cases on page 95-97 in the textbook
2). Discuss the questions on page 98-99 in the textbook.
3). A 33-year-old woman undergoes a lymph node biopsy of her deep cervical nodes on the
left side of her neck. Immediately following surgery, she complains of weakness in her
left shoulder. On exam, the left shoulder droops, and she is unable to raise the point of
her shoulder. She denies numbness in her shoulder, back, and neck.
Questions to consider:
①. What nerve appears to have been inadvertently cut during the biopsy?
A. Greater occipital n.
B. Spinal n. C3
C. Dorsal scapular n.
D. Accessory n. (Cranial Nerve XI)
E. Cutaneous nn. of the back (dorsal primary rami)
②. In most peripheral nerve injuries, there is usually characteristic sensory loss,
producing numbness in a specific area. Which of the following best explains why
there is no numbness in this case?
A. The motor part of CN XI must have been damaged, while the sensory part
remained intact.
B. The spinal accessory nerve is unique among peripheral nerves in that it does not
carry any sensory fibers whatsoever.
C. Sensory loss is not expected from damage of this nerve because no peripheral
nerve that innervates a skeletal muscle of the upper limb carries sensory fibers.
D. Nerves that innervate skeletal muscles carry only motor neurons, and cutaneous
sensory nerves carry only sensory neurons.
③. Since the spinal accessory nerve carries no proprioceptive fibers, which of the
following best explains the ability to execute coordinated movement of the trapezius
muscle?
A. Because the trapezius m. is the only muscle that inserts on the acromion,
allowing for elevation of the shoulder, the central nervous system does not need
proprioceptive feedback for coordinated movement of that muscle.
B. Proprioceptive fibers from nerves innervating other muscles that also insert on
the clavicle and scapula, including levator scapulae m., rhomboid major m.,
rhomboid minor m., and sublavius m., provide enough sensory information to the
central nervous system that coordinated movement of the trapezius m. can occur
without proprioceptive information from that muscle.
C. The greater occipital n., a branch of C2, sends proprioceptive fibers from the
nuchal ligament and the trapezius m. to the central nervous system to allow for
coordinated movement.
D. Spinal nerves C3 and C4 carrying proprioceptive fibers combine with branches
of the spinal accessory n. in the subtrapezial plexus before innervating the trapezius
m.
④. Following the spinal accessory nerve from its origin to its destination in the body,
which of the following sequences would best describe what you would find along the
way?
A. Association with the cervical spinal cord, passage through the jugular foramen,
association with proprioceptive fibers, passage through the foramen magnum,
innervation of the target muscles
B. Association with the C3 and C4 dorsal primary rami, passage through the
foramen magnum, passage through the jugular foramen, association with
proprioceptive fibers in the subtrapezial plexus, innervation of the target muscles
C. Association with the cervical spinal cord, passage through foramen magnum,
passage through the jugular foramen, formation of subtrapezial plexus, innervation
of target muscle along with proprioceptive fibers
D. Association with the C3 and C4 ventral primary rami, passage through the
foramen magnum, association with proprioceptive fibers, passage through the
jugular foramen, formation of the subtrapezial plexus, innervation of the target
muscles
E. Association with the C3 and C4 ventral primary rami, passage through the
foramen magnum along with proprioceptive fibers, passage through the jugular
foramen, disassociation from proprioceptive fibers at the subtrapezial plexus,
innervation of the target muscles
4). A 25-year-old man is brought into the ER with a high fever, lethargy, and a stiff neck.
After taking a history and performing a physical exam, you strongly suspect meningitis.
In order to find the causative agent, you order a lumbar puncture. Laboratory analysis
confirms your suspicion by showing bacterial growth in the cerebrospinal fluid (CSF).
You administer the appropriate therapy and the patient recovers without any
complications.
Questions to consider:
①. Where along the vertebral column is a needle inserted for a lumbar puncture? Which
landmark can you use to find this level?
②. During a lumbar puncture, the syringe needle is inserted in the midline and within
the median plane. Why? What structures, ligaments and others, does the needle
traverse before entering the lumbar cistern?
③. What position is the patient placed in during this procedure? Justify this
anatomically.
④. Following the procedure, the patient complains of a severe headache. What is the
cause of this complication of lumbar punctures?
⑤. Other than obtaining CSF samples, in what other situations are lumbar punctures
performed?
5). You are called to evaluate a newborn infant in the labor and delivery room. On physical
exam you note that the infant has normal vital signs and appearance with the following
exception - you note that the patient has a bulging cyst-like structure approximately 4
cm in diameter protruding from his back . You also note that he has limited movement
of the lower extremities and that both feet are plantarflexed and inverted at the ankle.
Questions to consider:
①. What are neural tube defects and how often do they occur?
②.
③.
④.
⑤.
⑥.
What types of anatomical structures can be involved with a case of spina bifida?
How do the various types of neural tube disorders vary in their presentation?
What is the cause of spina bifida?
What other complications are associated with this condition?
What simple prophylactic therapy can be undertaken prenatally to prevent such
defects?
6). Paramedics respond to a report of an 82 year old man unconscious after a fall. They find
the patient on the floor in his house in cardiac arrest. His wife said that he fell
approximately 18 inches from a lift assist device. The paramedics revive the patient to a
normal sinus rhythm using ACLS protocols (Advanced Cardiac Life Support) but the
patient remains profoundly unconscious. They fully immobilize his spine and transport
him emergently to the hospital. X-ray, CT, and MRI image studies at the hospital show
C1 and C2 fractures with spinal cord injury, resulting in quadriplegia. T2-T4 spinous
processes and several left ribs are also fractured. The patient never regains
consciousness and dies the next day.
Questions to consider:
①. What is the function of the dens of C2, and why are fractures in this region so
dangerous?
②. What is spinal immobilization, and why is it used?