Read the section on skeletal cartilages (p. 176).

• Make sure you understand the functional differences between the three types of skeletal cartilage.
• Learn the information in Marieb Fig. 6.1.
• See this site for a nice description of these cartilages.
• Understanding the difference between interstitial and appositional growth is important, and it will return when we cover bone growth.

Read the section on bone classification (pp. 176-178).

• This is fairly self-explanatory.
• Know that bones fall into two categories by region: axial and appendicular.
  • Those terms will come up again and again.
• Bones also fall into four broad categories based on shape: long, short, flat, and irregular.
  • This is illustrated in Marieb Fig. 6.2.
  • Ignore the comment on sesamoid bones; I just lump them in with short bones.
  • Also note that there can be some disagreement among anatomists regarding whether a bone is long or flat, for example. While the majority of the bones are straightforward, there can be some differences between books on others.

Read the section on the functions of bones (pp. 178-179).

• The first four functions are fairly self-explanatory.
• Hematopoiesis will become more important in A&P2.

Read the section on bone structure (pp. 179-184, up to and including the section called "Chemical Composition of Bone").

• This section contains the bulk of the material that I cover in this chapter and is important.
• Don’t learn the material in Marieb Table 6.1. I don’t cover bone markings in class.
• Learn the material in Marieb Fig. 6.3 and Marieb Fig. 6.6.
  • Much of the terminology in these figures will be reinforced in lab.
  • See Art-Labeling Activity for Marieb Fig. 6.3.
  • See Art-Labeling Activity for Marieb Fig. 6.6.
  • See animation – Femur Structure.
• Unfortunately, our textbook doesn’t show a photograph of a cross-section through a long bone, so take a look at Silverthorn Fig. 23-18 instead.

Read the section on the formation of the skeleton (pp. 184-186).

• This material will probably be the most challenging of the chapter. After you’ve read the section, I suggest you concentrate on the figures. (In class, I generally just lecture off of the figures.)
  • This figure of ossification during fetal life shows both types of ossification. Most of the bones (especially the long bones in the limbs) are formed by endochondral ossification, while the flat bones of the skull are formed by intramembranous ossification.
  • Marieb Fig. 6.7 (parts 1 & 2) does a decent job of illustrating intramembranous ossification, although the view is a little misleading. (I’ve looked through lots of other books, but no one else has improved on it.) You need to keep in mind that steps 1 & 2 are showing you a slice through a membrane, not a top-down view.
  • In terms of endochondral ossification, Marieb Fig. 6.8 does an adequate job of the early steps.
  • See animation – Endochondral Ossification.

Read the section on postnatal bone growth (pp. 186-187).

• Again, this section is somewhat abstract. While Marieb Fig. 6.10 is okay, I suggest you use Silverthorn Fig. 23-19 instead. There’s a bit more happening on the picture, but if you follow it closely, I think you’ll find it covers the topic of interstitial growth better than the Marieb.

Skim the section on bone remodeling, specifically the paragraphs on bone deposit and resorption (p. 188).

• There’s an unfortunate amount of detail in here that’s not really important.
• Just make sure you understand the principles of deposit and resorption, and the types of cells involved in each.
  • Your book glosses over a point that I stress in class quite a bit. Osteoblasts and osteocytes are developmentally related. The suffix -blast indicates an immature cell, meaning that osteoblasts are developmentally younger than osteocytes (-cyte refers to a mature cell). Once an osteoblast has become surrounded with matrix, it is technically called an osteocyte.
  • The suffix -clast refers to a cell that breaks something down. (In non-scientific language, an iconoclast is a person who attacks a cherished institution.) Osteoclasts are not developmentally related to the osteoblasts and osteocytes. Instead, they are derived from the hematopoietic cells that give rise to macrophages of the immune system – essentially making osteoclasts and macrophages “cousins.”
    • Osteoclasts are distinguished by their ruffled edge that makes contact with the bony matrix they resorb.
    • Resorption of this hard matrix is accomplished both enzymatically and with low pH. Look at Silverthorn Fig. 23-21 to see this in illustration form.
    • After looking at that figure, you should be able to draw on your Bio Principles background and tell me how the enzymes and acid (as H⁺) move across the osteoclast’s plasma membrane. (While I’ve never asked that on an exam, I consider that to be a perfectly fair exam question.)

Read the section on the hormonal mechanism of bone resorption and remodeling (pp. 188-190).

• Marieb Fig. 6.11 is a nice example of negative feedback, and it often appears on exams.
• There is one warning that you need to be aware of. The textbook implies that osteoclasts possess receptors for PTH and activation of the osteoclasts by PTH triggers bone resorption. In fact, osteoclasts do NOT possess PTH receptors. The receptors for PTH are, in fact, found on osteoblasts and osteocytes (remember: these are developmentally linked). When these cells bind to PTH, they become active and release soluble factors that, in turn, activate the osteoclasts.
• See the InterActive Physiology module – Electrolyte Homeostasis (pp. 33-36).
  • Click here for information on InterActive Physiology.
  • Once you arrive in the Electrolyte Homeostasis module, use the pull-down menu to skip ahead to page 33 (Calcium Homeostasis).

Learn the stages of bone fracture repair (p. 191).

• This can be most easily accomplished by concentrating on Marieb Fig. 6.13.
  • The text that accompanies the figure can be found in the right-hand column on p. 191, continuing onto p. 193. In lecture, I just use the figure and list the stages. I don’t cover the information in the left-hand column on p. 191.
  • See animation – Fracture Repair.
• I skip the types of bone fractures (Marieb Table 6.2, p. 192).

Lastly, you might be interested in this animation on osteoporosis. It does a nice job reviewing bone structure, as well.

Skeletal anatomy is fairly straightforward, but it’s sometimes difficult when you don’t have the bones in front of you. There are a number of online resources that you can use to help you get a “feel” for the bones, but nothing is as useful as touching the real thing. Bones have been put in the study room off of the lab (S-545); there is also a set in the ARC. Find me if something’s missing; I’m used to hunting for errant bones.

You are only responsible for some of the anatomical information for the lecture portion of the course, but there’s more that you need to know for Lab Exam 1. What I’ve tried to do below is to concentrate on the lecture portion of the course (i.e., what I talk about when I lecture to my day classes). As a result, you’ll see that I only talk about skeletal anatomy superficially in class. I have, however, pointed out pieces of information that may be helpful to read in preparation for the lab exam. Those passages will show up in pink.

Let’s get started…

Read the introductory material in Chapter 7 (p. 203), as well as the paragraph on the axial skeleton.

• On Lab Exam 1, I often will ask questions like “Is this bone part of the axial or appendicular skeleton?” Those are easy points.

Read the section on the skull up through (but not including) the facial bones (pp. 203-211).

• There’s a lot of detail in this section that you are NOT responsible for.
• In the end, I want you to know/be able to do the following:
  • Identify all eight cranial bones on figures (Marieb Figs. 7.2a, 7.2b, 7.3a, 7.3b, 7.4a, and 7.4b-c).
  • Identify the sutures that unite the cranial bones.
  • Describe the three “steps” in the cranial floor and the bones that comprise them.
    • Part c on Marieb Fig. 7.4 shows this nicely.
  • Identify the following bone markings and explain their significance:
    • Occipital bone: foramen magnum and occipital condyles
    • Temporal bones: tympanic region and petrous region (importance with respect to ear structures)
    • Sphenoid bone: sella turcica
    • Ethmoid bone: crista galli, cribriform plate, and the olfactory foramina
• There are a variety of resources at your disposal here:
  • See Art-Labeling Activities for:
    • Marieb Fig. 7.2a
    • Marieb Fig. 7.3a and Fig. 7.3b
    • Marieb Fig. 7.4a and Fig. 7.4b
  • See animation – Lateral View of the Skull.
  • See the gallery of 3D-rotatable bone images.

For Lab Exam 1, I recommend reading the section on facial bones, up through and including the paragraph on the inferior nasal conchae (starting on p. 211, up through p. 213).

• The left and right maxillae comprise the upper jaw.
• The mandible is the lower jaw.
• The zygomatic bones are the cheekbones. Note that the zygomatic bones articulate with the zygomatic processes on the temporal bones.
• You’re only responsible for learning the lacrimal bones from figures. They can be hard to see on the skulls in the lab, and our Beauchene skull (a skull that’s been “blown apart”; see Lab Manual Fig. 10.6c, p. 129) in the lab is missing its lacrimal bones.
• The palatine bones make up your hard palate. If you run your tongue along the top of your mouth, you feel a hard “ceiling” towards the front of your mouth and a softer part farther back. The hard part is your hard palate, made up of the palatine bones. The softer part in back is your soft palate; that’s just muscle.
• The inferior nasal conchae will come up again in the respiratory system in A&P2.
• Here are some resources dedicated to the facial bones:
  • See Art-Labeling Activities for Marieb Fig. 7.10a and Fig. 7.10b.
  • See 3D Rotate video clip – Facial Bones.
  • See animation – Features of the Skull (covers both cranial and facial bones).

Also for Lab Exam 1, you might want to read over the short paragraph on the hyoid bone (p. 218).

• The hyoid bone is in the neck and is the only bone not attached to the rest of the skeleton.
• It is embedded in the muscles and connective tissue of the neck.
• On the skeletons in the lab, it’s usually just represented as a piece of bone attached to the rest of the skeleton by a piece of wire.
• You see the hyoid bone come back in the respiratory system, due to its proximity to the larynx (voicebox).

Read the section on the vertebral column (pp. 218-225).

• Again, there’s a plethora of detail here, but you only need to concentrate on the following:
  • The information in Marieb Fig. 7.13 is important.
    • See 3D Rotate clip – Axial Skeleton (minus the skull)
    • See animation – Divisions and Curvatures of the Vertebral Column
  • Know the disorders associated with abnormal curvatures.
    • See Marieb Lab Manual Fig. 10.11 (p. 133).
  • Understand the functions of the ligaments and make sure you can see them on Marieb Fig. 7.14a.
    • The detail on the intervertebral discs is not important; just make sure you know that they are made of fibrocartilage and what their function is.
  • The general structure of vertebrae is important, since it is the foundation for distinguishing between the cervical, thoracic, and lumbar vertebrae.
    • Spend some time absorbing the information in Marieb Fig. 7.15.
    • The laminae and pedicles aren’t important; just know that together they make up the vertebral arch.
    • The superior and inferior articular processes are just the parts that articulate with the vertebrae that lie superiorly and inferiorly.
  • Understand how the cervical, thoracic, and lumbar vertebrae differ from each other.
    • See 3D Rotate video clips: cervical, thoracic and lumbar vertebrae
    • C₁ (atlas) and C₂ (axis) have radically different structures
      • See 3D Rotate video clip – Atlas and Axis.
    • Make sure you know why the lateral masses on C₁ and the dens on C₂ are important.
    • Use the figure in Marieb Table 7.2 (Parts 1 2) for help.
  • Don’t worry about the markings on the sacrum and coccyx.
    • Just know that they are formed from fused vertebrae (S₁-S₅; coccyx can be 3-5) and they make up the inferior aspect of the vertebral column.
    • See 3D Rotate video clip – Sacrum and Coccyx.

In the section called “Developmental Aspects of the Skeleton,” just read up on the difference between the primary and secondary curvatures of the vertebral column (two paragraphs on p. 247, first paragraph begins “Only the thoracic and sacral curvatures…”).

• Primary curvatures = thoracic and sacral – present at birth
• Secondary curvatures = cervical and lumbar – develop later
  • Cervical develops when the baby can hold its head up
  • Lumbar develops when the baby learns to walk
• Our textbook doesn’t show this well, but you can see it on Tortora Fig. 7.16c.

Read the section on the thoracic cage (pp. 226-227).

• Understand the function of the thoracic cage.
• In terms of anatomy, make sure you know the following:
  • The sternum is composed of three fused bones called the manubrium, the body (or the sternal body), and the xiphoid process. (Aren’t those names fantastic?)
  • There are twelve pairs of ribs and they come in three types (vertebrosternal, vertebrochondral, and vertebral).
    • I’d rather you NOT learn their “informal” names (i.e., true, false, and floating) only because their technical names actually tell you something about them. When I test on the ribs, I only accept the technical names.
• Remember: ribs are flat bones (not long bones). How can you tell this by looking at Marieb Fig. 7.20a?
• Also, what do we call the cartilage that connects the ribs to the sternum? And what type of cartilage is that?
  • Know that the bulk of the rib is called the shaft and they articulate with the thoracic vertebrae.
• See 3D Rotate video clip – Axial Skeleton (shows the thoracic cage nicely)

Read the introductory section on the appendicular skeleton (p. 227).

• Think a little bit about the differences in function between the axial and appendicular skeletons.
  

  I cover relatively little of the appendicular skeleton in lecture, concentrating only on the pectoral and pelvic girdle. As with the axial skeleton, additional bones (especially those of the limbs) are covered in lab. You are only responsible for those bones and their respective markings on the lab exam. Readings and activities related to lab material are listed in pink.

• See the Art-Labeling Activity based on Marieb Fig. 7.21.
  • It covers the bones of the girdles as well as the limbs.

Read the section on the pectoral (shoulder) girdle (pp. 227-231).

• The information on the mobility of the upper limb (in the second paragraph) is important.
• There is a lot of anatomical terminology that I’m not interested in (as far as the lecture material goes). Concentrate on the following features:
  • Clavicle
    - Sternal end – articulates with the sternum
    • Acromial end – articulates with the scapula
  • Scapula
    • Essentially, the scapulae are right triangles
      • Superior border – parallel to the shoulders
      • Medial border – parallel to the vertebral column
      • Lateral border – um… the other side?
      • There’s a figure in the Lecture Slides in which I’ve labeled these borders clearly.
    • Glenoid cavity – articulates with the head of the humerus
• See Art-Labeling Activity for Marieb Fig. 7.22a-c.
• See 3D Rotate video clip – Scapula, Clavicle, and Humerus.

That’s all I cover in lecture regarding the pectoral girdle/upper limb. The details regarding the arm, forearm, and hand bones are left for the lab. If you wish, you might want to read the section on the upper limb (pp. 231-237) in preparation for the lab.

• A couple of notes:
  • Your arm is the part from your shoulder to your elbow and only consists of your humerus. Your forearm extends from your elbow to the wrist.
  • Consult the Lab Exam 1 Review Sheet regarding the bone markings that you need to know for the lab exam.
  • You are not responsible for learning the individual carpals, nor do you need to know the proximal, middle, and distal phalanges (just learn them as a group).
• See Art-Labeling Activities for Marieb Figs. 7.22d, 7.23, and 7.24.
• See 3D Rotate video clips – Upper Limb and Wrist and Hand.

Read the section on the pelvic (hip) girdle (pp. 237-239).

• There’s quite a bit of anatomical terminology here as well. Focus on the following:
  • There’s often a bit of confusion regarding the following terms:
    • Pelvis – composed of the two paired pelvic bones (called os coxae or coxal bones); these are the bones that resemble elephant ears
      • The plural form of pelvis is pelves.
    • Bony pelvis – the two pelvic bones, as well as the sacrum and coccyx (both of which make up the posterior wall of the pelvis)
    • False pelvis – the roughly-oval space between the elephant ears
    • True pelvis – the deep bowl part of the pelvis that is encircled by bone; this is the part of the pelvis that contains the pelvic organs and through which babies are delivered
      • The true and false pelves are difficult to show in diagrams but are fairly straightforward when you’ve got the bones sitting in front of you in lab.
      • In the Lecture Slides, I’ve included a couple of figures that show you the difference between true and false pelves.
  • You should know that the pelvic bones are formed from three fuses bones called the ilium, ischium, and pubis (or pubic bone). The sites of fusion cannot be seen, but the names now apply to specific regions of the pelvic bones.
    • They have been colored for you on Marieb Fig. 7.27b and 7.27c.
  • Important markings:
    • Acetabulum – socket that receives the head of the femur
    • Ischial tuberosity – strongest part of the pelvic bones; also nice because they are prominent markings on the ischium
    • Obturator foramen – paired holes through which blood vessels and nerves pass to and from the lower limbs
    • Pubic symphysis – joint where the two pelvic bones meet; composed of a pad of fibrocartilage
    • Pubic arch – the angle created by the union of the two pelvic bones; important in distinguishing between male and female pelves
• See Art-Labeling Activity for Marieb Fig. 7.27a.
• See 3D Rotate video clip – Bony Pelvis.
• Make sure you understand the differences between male and female pelves, and how the female pelvis is modified for childbearing.
  • This is probably easiest with the actual bones/skeletons in the lab.
  • See animation – Male vs. Female Pelvis Differences.

Again, that’s all I cover in lecture. As with the upper limb, the bones (and their markings) of the lower limb will be covered in lab.

• Some pointers if you wish to keep reading:
  • There is only one bone that comprises the thigh, and that’s the femur.
  • Your kneecap is called the patella. It is classified as a sesamoid bone (because it’s roughly shaped like a sesame seed), although I usually refer to it as a short bone.
  • Your leg is technically the part of your lower limb that is below the knee, and it is composed of the tibia and fibula. The easy way to keep them straight is that the suffix –ula means small or diminutive (think miniscule). Of these two bones, the fibula is thinner than the bulky tibia.
  • As with the hand, the foot is composed of the tarsals, metatarsals and the phalanges.
    • The only two bones that you specifically need to know for the lab exam are the talus (which articulates with the tibia and fibula) and the calcaneus (the heel bone). The rest can just be learned as groups.
• Related media files:
  • See Art-Labeling Activities for Marieb Figs. 7.27b, 7.28, 7.29, and 7.31b-c.
  • See 3D Rotate video clips of the following:
    • Whole Lower Limb
    • Hip and Femur
    • Patella, Tibia, and Fibula
    • Ankle and Foot