Biology 143 Lab 4 4-1
In this lab you will be introduced to the structure and classification of bones and you will learn the axial skeleton in detail
Prelab
•
Label the diagram of the skeleton (p 2) and the long bone (p 3)
•
Label the skull diagrams on p 8 and 9
•
Label the vertebra on p 11
•
Complete pages 1,3, 5, 6, 7,10, 12, 13, 14
•
Label the flash cards at the end of this lab ( BIG HELPFULHINT : the labelled structures are the same ones mentioned in the text of the lab manual)
Objectives
This lab and the next lab involve a detailed look at the bones of the body. For each bone you are responsible for knowing the following:
1. the names of the bones of the axial skeleton and the bone landmarks (bumps and depressions), as indicated for each bone
2. the location of the bones in the body, and the relevance of the landmarks
3. the structure of a long bone
4. difference between compact bone and spongy (cancellous) bone tissue
Learning the skeletal system in detail will require continual review. Refer to the flash cards, locate the bones and landmarks on your own body, handle the bones in the lab.
AXIAL SKELETON
The skeletal system consists of the axial skeleton and the appendicular skeleton . This lab focuses on the axial skeleton.
Name the 3 main subdivisions of the axial skeleton : i) ______________________________________ ii) ______________________________________ iii) ______________________________________
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Biology 143 Lab 4 4-2
LABEL THE BONES INDICATED ON THE FOLLOWING DIAGRAM OF THE SKELETON
Indicate the bones of the axial skeleton (or colour the bones of the axial skeleton and the bones of the appendicular skeleton 2 different colours)
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Biology 143 Lab 4 4-3
PART 1.
GROSS ANATOMY OF A LONG BONE
Examine the bone that has been sectioned longitudinally . Locate the areas consisting of compact bone and spongy bone . Identify the following features: diaphysis, proximal and distal epiphysis, medullary cavity . Label these features below:
What type of bone tissue forms the walls of the diaphysis? _____________________________
What type of bone tissue predominates at the epiphyses? ____________________________
Note the epiphyseal plate(s) . What is the significance of these?
____________________________________________________________________________
What is found in the medullary cavity? _____________________________________________
Bone surfaces are covered with membranes.
Periosteum (covers external surface and is composed of a layer of dense irregular connective tissue overlying cellular layer richly supplied with nerves and blood)
Endosteum (covers trabeculae and lines bone cavities; is a cellular layer)
The periosteum and endosteum do not show on this bone. Why? _______________________
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Biology 143 Lab 4 4-4
BONE TISSUE
Examine the 2 slides of compact and spongy (cancellous) bone tissue
Compact bone (consists of osteons , as seen in bone tissue slide A; dense bone tissue which resists stress). Sketch an osteon below; label the central canal, canaliculi, an osteocyte, a lacuna
Spongy bone ( consists of web like trabeculae , as seen in bone tissue slide B; thin branching struts; less resistant to stress, but lightweight). Sketch some trabeculae below and show the location of the osteocytes
BONE CLASSIFICATION
Bones are classified by shape into 4 main categories: long bones irregular bones flat bones short bones
Examine the bones on the bench. Identify each bone and classify each one by shape.
1. _____________________________ 4. _____________________________
2. _____________________________ 5. _____________________________
3. _____________________________ 6. _____________________________
DYNAMIC HUMAN CD (if available)
Practice identifying the bones of the skull. When you click on a bone with the mouse, the name of the bone will appear. Examine the skull from various angles and sections. You are responsible for learning all bones, landmarks, sutures and sinuses identified in these images.
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Biology 143 Lab 4 4-5
AXIAL SKELETON (SKULL)
Using your text and flash cards as references, identify the following bones, landmarks and joints on the skulls provided.
A. CRANIUM : SKULL BONES
The cranium is the part of the skull that encloses the brain and is made up of 8 bones
1.
Frontal Bone (forms the forehead and roof of the orbits)
• frontal sinus
2. Parietal bones (right and left)
• sagittal suture (separates left and right parietal bones)
• coronal suture
Between parietal bones and _______________________ bone
• squamosal suture
Between parietal bones and _______________________bones
• lambdoidal suture
Between parietal bones and _______________________ bone
3.
Occipital bone
• foramen magnum
What passes through this opening? ___________________________________
• occipital condyles
Articulate with what? _______________________________________________
4.
Temporal bones (right and left)
• mastoid process (locate on yourself) and styloid process
• external acoustic (auditory) meatus (where sound enters the ear)
• zygomatic process
Together with the _____________________________bone forms the zygomatic arch (cheekbone)
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Biology 143 Lab 4 4-6
5.
Ethmoid bone
• crista galli (attachment site for membrane which secures brain within cranial cavity
• cribriform plate (forms roof of nasal cavity)
What nerve endings pass through the tiny holes here? _______________________
• perpendicular plate
What does this plate form? _________________________________________
• ethmoid sinuses (air filled spaces)
• superior and middle nasal conchae
What function do these serve? __________________________________________
NOTE: the bony nasal septum consists of the perpendicualr plate (superiorly), the vomer bone (inferiorly) and cartilage (anteriorly)
6.
Sphenoid Bone
• optic foramina (pl.) - singular: optic foramen - for passage of optic nerves
• sella turcica (“turkish saddle”- pituitary gland - hypophysis - sits here)
• sphenoid sinus
B. FACIAL BONES
1.
Maxillary bones (2 bones forming the upper jaw, the roof of the mouth, and floor of orbits.) .Locate maxillary sinuses
2.
Zygomatic bone forms " cheekbones " ; “chewing muscles” attach here
With zygomatic process of _______________________bone forms the zygomatic arch
3.
Nasal bones (2)
4.
Mandible lower jaw bone
5. Lacrimal bones lacrimal fossa allows __________________ to drain into nasal cavity
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Biology 143 Lab 4 4-7
C.
PARANASAL SINUSES
You have just located these sinuses lying within the frontal, ethmoid, sphenoid and maxillary bones. They are lined with pseudostratified ciliated columnar epithelium forming a mucous membrane and drain into the nasal cavity. When they are irritated or don't drain well as in a "head cold", you become very much aware of them by the pressure they exert within the skull bones. They will be mentioned again in the Respiration Lab .
D.
AUDITORY OSSICLES - (see in demo box) also (in ear model). malleus, incus and stapes located in petrous portion of temporal bone (smallest bones in body)
E.
HYOID BONE
Tongue and swallowing muscles attach to it.
Suspended by ligaments from the styloid processes of temporal bones
What is unique about this bone? ___________________________________________
Complete the diagrams which follow by labelling the bones, structures and sutures indicated.
There may be some small bones on this diagram not mentioned in the manual. Use your text, and locate each bone on a skull as you label it.
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Biology 143
ANATOMY OF THE HUMAN SKULL a) anterior aspect b) left lateral aspect
Lab 4 4-8
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Biology 143 Lab 4 c) inferior superficial view (mandible removed) c) superior view of cranial floor
4-9
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Biology 143 Lab 4 4-10
AXIAL SKELETON (VERTEBRAL COLUMN)
Using your text as a references and skulls available identify the following bones, landmarks and joints of the vertebral column.
A. ARTICULATED VERTEBRAL COLUMN
Identify then count the three types of vertebrae :
7 cervical vertebrae (HINT: breakfast at 7)
12 thoracic vertebrae (HINT: lunch at 12 noon)
5 lumbar vertebrae (HINT: dinner at 5)
Note how the vertebrae articulate with each other to form a flexible column of bone.
Note the intervertebral discs, vertebral canal and intervertebral foramina of the articulated vertebrae
What passes through the intervertebral foramina? _____________________________
What passes through the vertebral canal? _____________________________
What type of cartilage forms the intervertebral discs? _____________________________
What structures of the vertebra are sites of muscle attachment?
_______________________________and ____________________________________
B. BASIC STRUCTURE OF A VERTEBRA
Be able to identify the following on the model
•
body (centrum)
•
transverse process
•
vertebral foramen
•
spinous process
• superior articular process
What type of vertebra is represented in this model? _______________________________
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Biology 143 Lab 4
LABEL THE FEATURES OF A TYPICAL VERTEBRA ON THE DIAGRAM BELOW:
4-11
C. THREE TYPES OF VERTEBRAE
1 . Cervical vertebra : (C1 – C7)
These are the smallest of the separate vertebrae and allow the most mobility .
•
C1 (atlas) note it has no body - its superior articulating surface articulates with the occipital condyles of the skull allowing the “yes-yes” motion of the head
• C2 (axis) note the dens (odontoid process) which, with the transverse ligaments holding it against the anterior arch of the atlas, allows the "no-no" motion of head (rotation).
•
C
3
– C
7 examine one of the typical cervical vertebra provided for the following characteristics so that you will be able to distinguish a cervical vertebra from a thoracic or lumbar:
NOTE: bifid spinous process transverse foramina oval-shaped body
C7 can be easily palpated as a ‘bump’ at the base of the neck
Camosun College 2008

Biology 143 Lab 4 4-12
2. Thoracic vertebra (T1 to T12)
These vertebrae articulate with the ribs Distinguishing characteristics include:
• long, slender spinous process
• heart-shaped body
• costal facets on superior and inferior edges of body (centrum)
With what facet of the rib do these articulate? __________________________
• transverse costal facets on the transverse processes
With what part of the rib do these articulate? __________________________
3. Lumbar vertebrae (L1 - L5)
These are the largest of the vertebrae, and the least movable; they bear the weight of the torso.
Be able to distinguish a "classical" lumbar vertebra from a cervical or thoracic vertebra.
• stout body
• broad, short spine
• large flat transverse processes
What causes these vertebrae to be larger in structure compared to other vertebrae?
______________________________________________________________________
NOTE: Examine the vertebrae on the bench. Classify each as cervical, thoracic or lumbar.
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Biology 143 Lab 4 4-13
4. Sacrum : 5 fused vertebrae
Identify the following features of the sacrum:
• median sacral crest (spinous processes are fused)
• sacral foramina - for passage of spinal nerves and blood vessels
• auricular surface (auricle refers to the ’ear’; locate this ‘ear-shaped’ surface)
With what bone does this surface articulate? _____________________________
What name is given to this articulation (joint)? _____________________________
5.
Coccyx : 3-5 (varies) but usually 4 fused vertebrae (see skeletons).
EXAMINE THE ARTICULATED VERTEBRAL COLUMN
• intervertebral discs are located between the vertebrae.
Each disc consists of an inner gelatinous nucleus pulposus surrounded by a collar of collagen fibers and cartilage, the annulus fibrosus
What kind of cartilage comprises this collar? _____________________________
•
observe the herniated (prolapsed) disc (commonly known as a ‘slipped disc’).
This typically involves rupture of the annulus fibrosus followed by protrusion of the gelatinous nucleus pulposus
What causes the pain associated with
this type of injury?
_______________________________
_______________________________
_______________________________
Camosun College 2008

Biology 143 Lab 4 4-14
AXIAL SKELETON (THORAX)
1.
Sternum :
What important organ is protected by the sternum? _______________________
• manubrium of sternum
What bone articulates at the clavicular notch ? _____________________________
• body of sternum - note the notches for costal cartilages of (true) ribs #2 through #7
• xiphoid process - point of attachment for several ligaments and muscles
NOTE: CPR involves compression of the sternum. Landmarking before initiating CPR is used to avoid compression of the xiphoid process. Can you suggest why?
______________________________________________________________________
2.
Ribs : (12 pairs)
Define:
• true ribs (7 pairs)
• false ribs (5 pairs)
_________________________________________
_________________________________________ of which 2 pairs are floating ribs ________________________________________
On each rib identify:
• head note the two facets on the head which articulate with the costal facets on the thoracic vertebrae
• neck of rib
• tubercle with facet for articulation with transverse process of vertebra
• costal groove
• costal cartilages intercostal blood vessels and nerve lie in here
(see skeleton)
What type of cartilage is this? _________________________________________
Examine the skeleton at STATION 10 and note how the ribs articulate with the thoracic vertebrae. Review the names of all of the major bones at this station (see diagram p 2).
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Biology 143 Lab 4 4-15
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Biology 143 Lab 4 4-16
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Biology 143 Lab 4 4-17
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Biology 143 Lab 4 4-18
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Biology 143 Lab 4 4-19
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Biology 143 Lab 4 4-20
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Biology 143 Lab 4 4-21
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Biology 143 Lab 4 4-22
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