Part I: Skeletal System Structures, Functions, and Disorders

SKELETAL STRUCTURES

Objectives for Exam #1: 1. Provide information on the various structures and functions of the skeletal system. 2. Describe various skeletal system disorders, including imaging techniques used to diagnose these disorders.

Part I: Skeletal System Structures, Functions, and Disorders Your group will have an opportunity to cycle through four different stations. If you complete a station before other groups, review answers to completed questions, or begin working on the portfolio assignment.

Station A: Bone Structure 1. Using the model at your table (and p. 72-73 of the Human Body), label all of the following on the photo below: Include: periosteum, compact bone (where the osteons are), spongy bone (just a small amount), medullary canal (includes bone marrow).

2. Sketch a single osteon from the model. Label: osteocytes, Haversian (central) canal, blood vessels (vein, artery), nerve.

3. Fill in the basic functions of the following bone structures (Human Body, p.72). Structure Function

Periosteum

Medullary Canal

21 4. Where is the epiphyseal plate in a long bone, and what occurs in this region of bone until about the age of 17 (Human Body, p. 74)?

Station B: Skull and Spinal Vertebrae 1. How many bones make up the skull? ______

2. Look at the sutures where bones come together in the skull model and think about the ways bones come together in other parts of your body (like your knee or hip). How do the suture joints of the skull differ from most other joints in the human body?

3. From the model at the table (and Human Body, p. 68-69), how many vertebrae (“back bones”) are in the spine? ______

4. There are three main types of vertebrae, in three zones of the spine. ______vertebrae support the head, the ______vertebrae anchor the ribs, and the ______vertebrae provide a strong center of gravity for stable movement. (Human Body, p. 68-70)

5. There is a model at the table showing the effect of the disease osteoporosis on vertebrae. Of the three vertebrae, one is normal, one has lost some bone density, the third has a severe loss of bone density. Which vertebra shows the most bone loss in the model (top, middle, bottom)? ______

6. Cartilage discs between the vertebrae absorb forces and give the spine flexibility. The model of a spinal prolapse (slipped disc) at your table indicates the prolapsed area with a red color. What is the prolapsed disc touching (causing pain)? ______(also refer to p. 321 of Human Body)

7. Magnetic resonance imaging (MRI) uses radio waves within a magnetic field. These images can be used to monitor blood flow through vessels, and subtle changes in tissues. The lumbar spine MRI can sometimes show whether a disc is herniated (prolapsed, bulging, ruptured, slipped). It cannot show other conditions like muscle strain. The two lumbar spine MRIs are taken from two different individuals. Which MRI (A or B) shows a prolapsed disc? ______

Station C: Arm and Leg Structure 1. Using the model of the full human skeleton and your text, indicate the location of each of the following bones (arm or leg, upper or lower, such as located in the lower arm).

Bone Humerus Femur Radius Ulna Tibia Fibula

Location

22 2. Referring to the x-rays from two patients, which bone(s) are broken in patient A’s x-ray? ______In patient B’s x-ray? ______

3. Using the model provided of what is commonly called a “hip fracture” in elderly people, which bone is actually frequently broken? ______The model indicates different places where the fractures can occur (the red lines). How many different fractures are shown in the model? ______

4. A majority of humans experience disorders associated with the knee joint at some time in their lives. This is in part due to the degree of impact on the joint through frequent use. Referring to the model of the knee, which bones come together in the knee joint? (Human Body, p.76-77)

5. The knee has tendons and ligaments that permit a wide range of movement. Tendons connect ______to ______, and the ligaments connect ______to ______.

6. Of the various types of joints in the human body you are reading about this week, the knee joint is classified as a ______synovial joint. (Human Body, p.78-79)

7. Find the meniscus in the model. Based on its location, what is the function of the meniscus? ______If a knee is twisted quickly, what can happen to the menisci? Considering what the menisci do, why is this potentially a serious injury?

Station D: Hand and Foot Structure 1. Using the hand model, how many bones are in the hand? ______(Human Body, p. 64)

2. Loosely sketch and label the locations of the carpals, metacarpals, and phalanges.

3. Try the hand grip “strength test.” How many PSI (pounds per square inch) do you get for your right hand? ______Your left hand? ______Do only a few muscles contract as you grip, or do many muscles contract together? ______

23 4. The hand has similar structure to a foot. The carpals of the hand are equivalent to the ______of the foot. The metacarpals are equivalent to the ______, and the phalanges are named the same in hands and feet.

5. X-rays are small amounts of electromagnetic radiation. Soft tissues of the body (skin, fat, and muscle) allow most of the x-rays to pass through and these tissues appear dark gray on the x-ray photo. Fewer x-rays pass through denser tissues (bones, tumors, etc.) and these tissues appear light in the photo. X-rays may show large deviations like a break in a bone, but do not reveal a lot of detail of internal organs. Looking at the copy of the x-ray provided, what bone appears to be broken? ______