4 Lab 6 The Skeletal System

Lab 6 Handout

Figure 1. Bone tissue

Activity 6.1 Labeling Figures

INSTRUCTIONS: Label the structures from Figure 1 on the figures below. Draw in any missing structures. You may use color to enhance your drawings.

Figure 2. Human Skeleton, Axial and Appendicular

Figure 3. Line Drawings – Human Skeletons, (Left – Anterior View, Right – Posterior View)

INSTRUCTIONS: Label the structures from Figure 2 onto Figure 3.

 

The Cranial Bones of the Skull

The bones of the skull consists of cranial and facial bones. A description of each bone is provided below.

Cranial bones (8 total)

Frontal bone: Forms part of the pterion, where the frontal, parietal, sphenoidal, and temporal bones meet to form the ‘forehead’

Parietal bones (2): There are two parietal bones that form the side walls of the skull

Temporal bones (2): There are two temporal bones that form the skull near the ear

Occipital bone: The main bone of the occiput, the back and lower part of the skull

Sphenoid bone: A complex bone forming the eye socket and base of the skull; creates part of the lateral cranium exterior on both sides

Ethmoid bone: Forms the roof of the nasal septum, part of the nasal cavity and the medial wall of the orbit

Facial bones (14 total)

Maxilla (2) This is the upper jaw bone and includes the maxillary cavity

Mandible: The largest and strongest facial bone, forming the lower jaw

Lacrimal bone (2): The smallest and most fragile facial bone, located in the orbit to form medial eye socket

Zygomatic bone (2): Forms the cheekbone and part of the eye socket

Palatine bones (2): There are two palatine bones, located above the uvula in the throat, forming roof of the mouth

Vomer –This plow-shaped bone forms the midline of the nasal septum

Nasal (2) –These pair of bones form the nose bridge

Inferior nasal conchae (2): A pair of boney projections in nasal cavity that help warm, moisten, and cleanse the air as it passes through the turbinates (tiny structures within the nose).

Skull (Cranial + Facial Bones=22 bones total)

Figure 4. Human Skull

Figure 5. Line Drawing of Human Skull (Anterior View)

INSTRUCTIONS: Label the structures from Figure 4 onto Figure 5.

Figure 6. Human Skull (Lateral View)

Figure 7. Sutures/structures found in the skull (Lateral view)

Figure 8. Line Drawing of Sutures/structures found in the skull (Lateral view)

 

INSTRUCTIONS: Label the structures from Figure 7 onto Figure 8.  

 

Figure 9. Vertebral Column (Lateral views)

Figure 10. Vertebrae (Labeled structures)

Figure 11. Sacrum

Figure 12.  Three Types of Vertebrae (Top row- Superior view, Bottom row – Lateral view)

 

Table 6.1 Features found on the 3 types of vertebra

Feature	Cervical Vertebra	Thoracic Vertebra	Lumbar Vertebra
Number of Vertebrae	7 (C1-C7)	12 (T1-T12)	5 (L1-L5)
Location	Neck	Upper and mid-back	Lower back
Size	Small and lightweight	Medium-sized	Largest and heaviest
Body Shape	Small vertebral body	Heart-shaped vertebral body	Large, kidney-shaped vertebral body
Transverse Foramen	Present (for vertebral arteries)	Absent transverse foramen	Absent transverse foramen
Spinous Process	Short and bifid (split)	Long and angled downward	Short, thick, and horizontal
Articulation	No rib articulation	Articulates with ribs (costal facets)	No rib articulation
Facets for Articulation	Articular facets are small and face upward/downward	Costal facets on the sides for ribs	Larger, more robust facets that face medially/laterally
Mobility	Highly mobile (allows for rotation, flexion, and extension)	Limited mobility (primarily allows for rotation and some lateral flexion)	Limited mobility (allows for flexion, extension, and slight lateral flexion)

Activity 6.2 Distinguishing the 3 different vertebrae types in the vertebral column

INSTRUCTIONS: Transfer all information in black bold in Table 6.1 to the vertebral structures in Figure 12 by labeling. Draw a line pointing to the structure. If the structure is absent, write the name of the structure that is absent beneath the figure as “absent”. Be sure to include information from column one in each of your labels. For example, the first label would be, ‘Small vertebral body’ and would go on one of the 6 figures.

Table 6.2 Purpose of Features Found on the Sacrum

Structure	Purpose
Sacral Promontory	Serves as a key anatomical landmark; supports the weight of the upper body and connects to the lumbar spine.
Body of the First Sacral Vertebra	Provides structural support and stability; forms the base of the sacrum, articulating with the lumbar vertebra.
Transverse Ridges	Indicate the fusion points between sacral vertebrae; contribute to the overall stability of the sacrum.
Anterior Sacral Foramina	Allow the passage of nerves and blood vessels; provide routes for the sacral nerves to exit the sacrum.
Apex	The pointed end of the sacrum; articulates with the coccyx and helps form the posterior pelvic wall.
Coccyx	Serves as an attachment site for ligaments and muscles; provides support when sitting and contributes to pelvic stability.
Sacral Canal	Contains the spinal nerves and the cauda equina; protects these structures as they travel through the sacrum.
Body	Provides structural integrity; supports the weight of the upper body and aids in the distribution of forces through the pelvis.
Median Sacral Crest	Forms a ridge along the dorsal side of the sacrum; provides attachment points for muscles and ligaments.
Posterior Sacral Foramina	Allow the passage of sacral nerves and blood vessels; facilitate communication between the sacrum and surrounding structures.
Facet of Superior Articular Process	Articulates with the inferior articular process of the lumbar vertebra; contributes to the stability of the lumbosacral junction.
Auricular Surface	Forms a joint with the ilium of the pelvis; crucial for the sacroiliac joint, allowing for weight transfer between the upper body and lower limbs.
Lateral Sacral Crest	Provides attachment points for muscles and ligaments; supports the overall structure of the sacrum.
Sacral Hiatus	An opening at the inferior end of the sacral canal; allows for access to the epidural space for medical procedures such as

Activity 6.3 Clinical application of the sacrum in Injures

The sacrum is a crucial anatomical structure that consists of five fused vertebrae, forming a triangular bone at the base of the spine. It connects the lumbar spine to the pelvis and consists of various features, each with specific functions.

Sacral Promontory: A significant landmark for weight-bearing and connecting to the lumbar spine.

Transverse Ridges: Indicate fusion points, providing stability.

Anterior and Posterior Sacral Foramina: Allow the passage of nerves and blood vessels.

Coccyx: Serves as an attachment for ligaments and muscles, contributing to pelvic stability.

Sacral Canal: Houses the spinal nerves and protects them as they traverse the sacrum.

Auricular Surface: Forms the sacroiliac joint with the ilium, facilitating weight transfer.

Median Sacral Crest: Provides muscle attachment points and adds to structural integrity.

Scenarios

INSTRUCTIONS: Review the scenarios below. Use these key features of the sacrum to answer the questions.

Choose from the list below to answer the first question of each scenario

• Sacral Fracture from a Fall
• Lumbar strain of the lumbar vertebra
• Sacroiliac Joint Dysfunction
• Sacral Herniated disc
• Sciatica
• Sacral Spondylolisthesis
• Degenerative Disc Disease Affecting the lumbosacral region
• Osteoporosis
• Pelvic fracture
• Fibromyalgia of the sacrum
• Infection in the Sacral Region (Osteomyelitis)
• Piriformis syndrome

Scenario 1:

A 75-year-old female patient falls at home and presents with severe lower back pain.

Upon examination, she cannot bear weight on her legs, and there is noticeable tenderness over her sacral region.

Questions:

What type of injury is suspected?

 

What initial assessment should be performed?

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Scenario 2:

A 30-year-old male patient complains of pain localized to the lower back and buttock area that worsens with prolonged sitting.

He reports recent changes in his exercise routine, including heavy lifting.

Questions:

What condition might be causing the patient’s symptoms?

 

What physical assessments should be conducted?

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Scenario 3:

A 50-year-old diabetic patient presents with fever, swelling, and redness over the sacral area.

He reports chronic pain in the region and a history of pressure ulcers.

Questions:

What condition are you suspecting?

 

What diagnostic tests would be appropriate?

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Scenario 4:

A 60-year-old male patient reports chronic lower back pain radiating into his legs.

He describes a history of herniated discs and worsening pain with movement.

Questions:

What condition is likely affecting this patient?

 

What non-invasive treatments can be recommended?

INSTRUCTIONS:

Assemble the vertebra for your disarticulated skeleton, including the discs. Take a snapshot and upload to your LMS.