ANSC511 Lab2 Skeletal System Objective Sheet KEY PDF

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Download ANSC511 Lab2 Skeletal System Objective Sheet KEY PDF

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Name: TA COPY Lab Section: KEY

Lab 2 Objectives Sheet: Skeletal System

1. Bone morphology, bone shapes, and vertebrae. Use the bone models provided to answer these questions. a. Bones come in four shapes. There are examples in front of you. List the four shapes below, an example of each, and their function: i. Short: wrist, ankle. Provide stability and some movement. ii. Long: arm, leg, toe bones. Support body weight and assist with movement. iii. Flat: cranial, sternum, pelvic girdle. Protect internal organs such as heart and pelvic organs, can also provide attachment for muscle. iv. Irregular: vertebra, floor of skull, facial. Can help protect internal organs via their unique and specific shapes. b. What is the function of vertebral foramen and transverse foramen? Vertebral foramina allow the spinal cord and nerves to pass through, transverse foramina allow for blood vessels. Transverse foramina are only found in cervical vertebrae. c. There are models of different vertebrae in front of you. Using them as a guide, identify the characteristic features of the following vertebrae that allow you to tell them apart from one another. i. Cervical (7): contain 3 foramina (vertebral and transverse). Also contain the unique vertebrae, the atlas (C1) and axis (C2) ii. Thoracic (12): vertebral body contain shallow indents called costal facets which allow for rib attachment, stout centrum (body), short but prominent transverse processes, elongated spinous process, no transverse foramina. iii. Lumbar (5): no transverse foramina, no costal facets, larger vertebral bodies due to more weight distribution here. d. There are two special cervical vertebrae that are important for head movement. Name them (also include their vertebral number), describe their unique features, and how they facilitate head movement. i. Atlas (C1): only vertebra without a body, carries the weight of the head, allows you to nod. ii. Axis (C2): has a unique process called the dens process. Allows the atlas to rotate on the process and therefore allows you to rotate your head. e. Know how to identify the sacrum. What is the sacrum’s primary function and what feature allows it to do this? The sacrum is the fourth region of the spine. It is large, composed of 5 fused vertebrae, and looks like a shallow, triangular bowl. Its large, wedge-shaped structure is beneficial for weight bearing and balance.

f.

Now that you’re familiar with the different types of vertebrae, label the 5 regions of the vertebral column below:

g. Look at the cut long bone. See if you can identify the features we discussed in lecture (spongy vs. compact bone, epiphyseal plate, etc.). Label the diagram below with the features in the key. Projection (head) Epiphysis Spongy bone Epiphyseal plate

Compact bone

Diaphysis

projection, depression, hole, epiphysis, diaphysis, epiphyseal plate, compact bone, spongy bone, periosteum (this image does not show this structure well, please ignore it here. See Slide 7 in you PowerPoint for a better look at periosteum and endosteum)

Medullary cavity

hole

Epiphysis Projection (head). Articular cartilage found here

2. Human/whole skeleton. Answer the following: a. What 4 bone structures make up the appendicular skeleton? Pectoral girdle, upper extremities, lower extremities, pelvic girdle

b. What 5 bone structures constitute the axial skeleton? (Hint: one of these is a small floating bone… You should be familiar with it and its function) Skull, vertebral column, ribs, sternum, hyoid bone c. Examine the ribs on the human skeleton model. Identify which ribs are true, false, and floating and explain why: i. True: ribs 1-7, attach to sternum via their own cartilage (aka their own individual attachment point) ii. False: Ribs 8-12. Do not attach to sternum via their own cartilage. Ribs 8-10 attach via rib #7’s cartilage. iii. Floating: Ribs 11-12. They do not attach to the sternum at all. They are a type of false rib and therefore included in that category. For clarification: not all false ribs are floating ribs, but all floating ribs are false ribs. d. What is the difference between the leg and thigh bones? What are their functions? Which is weight bearing? Which is the heaviest bone in the body? Thigh bone = femur, lower leg = tibia and fibula. Femur bears weight and is the heaviest and longest bone in the body. Tibia is larger than the fibula and serves as the weight bearing bone of the leg, while the fibula does NOT bear weight and instead serves as an attachment point for muscles. e. What is a sesamoid bone? Provide an example (hint, check the leg). A bone that is embedded in tendons or muscles. Patella (aka kneecap, however please use its true name). They protect tendons and ligaments from stress and wear. f.

The skull is very complex and contains many bones and functionally unique structures. Examine the human skull and answer the following: i. Locate the ethmoid bone. What is its function? This bone also contains olfactory foramina. What is the function of this structure? Separates brain and nasal cavity. Olfactory foramina serve as passages for nerves to transmit smell to the brain. ii. In what bone is the auditory/acoustic meatus found and what is its function? Temporal bone. Serves as a passage for vessels and nerves from the inner ear. iii. Find the styloid process. What functions does it serve? Anchor point that connects to the hyoid bone, tongue, and larynx via muscle. Also found in the temporal bone. iv. What is the foramen magnum and what function does it serve? A hole in the occipital bone on the inferior side of the skull where the brain ends and the spinal cord begins.

g. Take a look at the model of the human skeleton. Take some time to familiarize yourself with the bones we went over in the lecture. Using the model as a guide, label the bones of the human skeleton below:

3. Comparative anatomy. Take a look at the variety of animal skeleton models/photos in front of you. While structurally these animals appear different, it’s important to remember that different animals have the same bones with slight differences in appearance in order to help an animal achieve a certain evolutionary function. a. Look at the image of the bird skeleton and answer the following questions. i. Below the bird’s ribs there is a large crescent-shaped bone called the keel. What type of bone is this? In other words, what bone is this equivalent to in other animals? Why has this bone been modified this way in the bird? (aka, what is its function?) The keel is a modified sternum. It provides surface area for the attachment of flight muscles.

ii. You might think that wings are made up of different bones than normal upper extremities, but they’re more similar than you’d think (they’re basically modified arms!). Name the bones that comprise the wing, in order of proximal to distal. Humerus, radius and ulna, carpals, metacarpals, phalanges iii. The beak is comprised of what face bone? (upper and lower) Upper and lower mandible (modified jaw bones) b. Compare the human skeleton to animal skeletons. Note differences between the two for the following bones and why these structures vary in the human. i. Skull: Human typically have larger, more rounded cranial areas of their skulls due to having to store larger brains (larger brain to head ratio ii. Spine: Human spines widen the more inferior you go down the spine, they also have more curvatures. The widening functions to bear upper body weight and the curvatures serve to help balance that weight. iii. Caudal vertebrae: These are tail vertebrae. Certain animals have many moveable caudal vertebrae to help provide balance, while humans have a reduced and fused, immoveable tailbone called the coccyx. Humans do not need tails anymore. iv. You may notice that humans overall have angled lower appendages, broad pelvises, curves in the spine, ached feet etc. What is the purpose of all these features? The human skeleton is made up of bony mechanisms to support and balance bipedal weight, and the angles in our bones help do this. c. Observe the horse, cow, and dog skeletal models. i. The radius and ulna of these animals are often fused, meaning they cannot supinate (or turn their palm) like humans can. What purpose does this serve for these animals? For animals that run and jump, having moveable wrists would be dangerous as it could result in leg injuries when running. Fused radius and ulnas provide stability for these animals. ii. Examine the hooves of the cow and horse. What type of bone forms the hooves? If humans were to walk on these bones, what part of our foot would we be walking on? Phalanges. This would be equivalent to humans walking on their fingers and toes. iii. If you examine the pectoral girdle of the horse, you’ll notice that it’s missing a certain bone. What bone is missing and why might this be beneficial to the horse? Clavicle. This helps a horse run and jump because not having a clavicle allows for maximum leg movement and retraction. d. Look at the cat skeleton, particularly the pectoral girdle and vertebral column. What do you notice? How might this help with a cat’s locomotion, particularly the ability to jump from large heights? Cats have a floating clavicle so there is no direct connection to their vertebral column and their pectoral girdle. This prevents shock from travelling up the spine and allows them to jump from high places unharmed. 4. Joint Movement: Familiarize yourself with the different joint movements. Using the provided text, practice these movements. To test your knowledge, work with your partner. One of you can perform a motion and the other can guess what it is. Describe the joint movements below: a) Abduction: movement of limbs in the coronal plane away from the body (abduct = take away). Taking away a part of body in a lateral direction b) Adduction: the return of the part of the body to anatomical “normal” position after abduction

c) Flexion: a decrease in the joint angle from anatomical position ex: bend your elbow is flexing the forearm d) Extension: a return to anatomical position of the part of the body that was flexed e) Hyperextension: extending a part of the body beyond the anatomical position ex: bowling f) Rotation: circular movement of a part of the body g) Lateral rotation: moves the anterior surface of a limb toward the lateral side of the body h) Medial rotation: turns the anterior surface of the limb toward the midline i) Supination: lateral rotation of the hand j) Pronation: medial rotation of the hand k) Protraction: horizontal movement in the anterior direction l) Retraction: reverse of protraction m) Elevation: to move in a superior direction ex: shrugging shoulders n) Depression: opposite of elevation; movement in the inferior direction o) Inversion: movement of the feet medially so they face each other p) Eversion: turning the soles of the feet laterally

5. Joints: Use the joint models, your book, as well as the gifs on the screen to assist you with answering the following. a. Describe each of the four joint types and name an example of each. i. Bony: two bones fuse into one, immoveable, skull sutures or sacrum ii. Fibrous: connect one bone to another with collagenous fibers. Ligaments iii. Cartilaginous: bones held together by cartilage, if it is between bones it is immoveable, sternum and rib connection is an example or pubic symphysis iv. Synovial: joints that allow for extensive movement, use synovial fluid to lubricate and reduce friction inside of a joint, includes shoulder, hip, elbow, etc. b. Describe the three types of movement and what joint types are associated with these movements: i. Synarthrotic: immoveable, includes bony joints ii. Amphiarthrotic: semi-moveable, includes fibrous and cartilaginous joints iii. Diarthrotic: freely moveable, includes synovial joints c. Based on the models and videos, describe the types of synovial joints. Include a description of the types of movement they are capable of and name examples of each. Additionally, draw diagrams of the joint movements in the space below. i. Plane: movement between two flat surfaces, include between carpals and tarsals i. Hinge: allow for angular movement. Elbow or knee ii. Pivot: allow for rotational movement between two bones. Radius and ulna or atlas and axis iii. Chondyloid (ellipsoid): allow significant movement between two planes. Between radius and carpals. iv. Saddle: provides for more movement in the thumb (humans) or pastern joint (animals) v. Ball and socket: extensive movement in these joints, but less stable. Hip or shoulder...