Lab 6 The Skeletal System

The Skeletal System PRE-LAB QUESTIONS 1. List the functions of the skeletal system. a. The function of the skeletal system is to protect and support the body, it supports and allows movement, produces new blood cells and stores nutrients for the body 2. What material contributes the most to the compressive strength of bone? a. The material that contributes the most to the compressive strength of the bone is calcium carbonate 3. Briefly describe the process of bone remodeling. a. Bone remodeling is a continuous process to replace old bone with new bone. The stages of remodeling involve living cells, osteoblasts, and osteoclasts. The stages are resting stage, bone resorption, transition, and bone formation. This cycle continues for the span of an organism life. 4. Research Wolff’s Law. How does the formation of torus mandibularis relate to this theory? a. Wolff’s law states that bones adapt based on needs/stress/demands. An evolved/remodeled bone shows there was stress, or force on that bone requiring a chance in structure. The formation of the torus mandibularis relates to Wolff’s law, because this a bone reaction/adaption to some type of pressure or stress. Research shows this may be related to grinding of the teeth. 5. Given your understanding of Wolff’s Law, what mechanical consideration would be important when designing a bioreactor for osteocyte growth ex vivo? a. Considering Wolff’s law, when designing a bioreactor for osteocyte growth ex vivo, it would be important to design the bioreactor so that you could determine adaptations that are created by stress/demands. It would also be important to ensure the bioreactor did not put any unwarranted stress/pressure on the osteocyte to encourage adaptions The Skeletal System EXPERIMENT 1: CLASSIFICATION OF BONES Data Tables Table 6: Classification of Numbered Bones Bone Name Classification by Shape Classification by Location Femur bone Long bone Appendicular Skeleton Vertebrae Irregular bone Axial skeleton Sternum Flat bone Axial Skelton Radius Long bone Appendicular Skeleton Knee Cap (patella) Sesamoid bone Appendicular Skeleton Humerus Long bone Appendicular Skeleton Tarsals/Carpals Short Bone Appendicular skeleton Fibula Long bone Appendicular Skeleton Ulna Long bone Appendicular Skeleton Ribs Flat bone Axial skeleton Post-Lab Questions 1. Why is it important to classify bones? a. It is important to classify bones, to increase knowledge about them through education and research. Classifying bones makes it easier to initially identify, and therefore treat depending on the bone and the condition. 2. Aside from length, what are some other common characteristics of a long bone? Are long bones typically associated with the axial or appendicular skeleton? a. Long bones are typically associated with the appendicular skeleton because this skeleton includes limbs, and long bones are often limbs. b. Beyond length, other characteristics of long bones include: i. being associated with the appendicular skeleton ii. widening near the end of the bones (near the epiphyses) The Skeletal System iii. long bones have both a cortical shaft called the diaphysis and epiphysis which is the spongy bone ends 3. Compare and contrast flat bones and long bones. a. Differences between flat bones and long bones are: i. Long bones are not as flat as flat bones ii. Flat bones tend to be curved whereas long bones are not iii. Long bones have yellow marrow in adults, red for flat bones b. Similarities between flat and long bones are i. They are both bones ii. Flat bones are generally found in the axial skeleton, and long bones are generally found in the appendicular skeleton The Skeletal System EXPERIMENT 2: DIGITAL SLIDE IMAGE EXAMINATION BONE Post-Lab Questions 1. Identify the indicated components in the slide image. A______Interstitial Lamellae___________ B______Haversian Systems ___________ C_______Concentric Lamellae_________ D_______Haversian Canals__________ The Skeletal System Identify the indicated components in the slide image. A_______ Trabeculae (in spongy bones) __________ B_______ Marrow Cavity __________ 1. Compare and contrast the structures of cortical bone and trabecular bone. a. Similarities between the structures of cortical trabecular bones are that they provide support and structure to the body b. Differences between the structures of cortical trabecular bones are the surface to volume ratio (trabecular bone has a larger surface area), and that the trabecular bone has more water concentration 2. What is the purpose of cortical bone and trabecular bone? The Skeletal System a. The purpose of the cortical bone is to give it the appearance we know and recognize in bones (strong, white smooth appearance) b. The purpose of the trabecular bone is 3. What are trabeculae? What is their function? a. The function of the trabeculae is to provide support to spongy bone on the ends of long bones. Trabeculae is a tissue found in bone 4. What are Haversian systems? What is their function? a. Haversian systems are small tubes/tunnels in our cortical bones. The function of Haversian systems are the home to nerve fibers, allowing bones to retrieve needed oxygen and nutrition The Skeletal System EXPERIMENT 3: OWL PELLET DISSECTION Data Tables Table 7: Owl Pellet Observations Pellet Characteristics Observations Pellet Length (cm) 5.25cm Pellet Width (cm) 2.25cm Physical Observations small, oval shape. Dry outside with flaky dirt like appearance. Easily to break apart, soft in structure. No significant smell noted, but a slight dirt like scent Table 8: Animal Bone Observations Bone Animal Source Number of Bones Skull Rodent 1 Jaw Rodent 2 (two sides appearing to be from the same animal) Scapula Mole 2 Rib Mole? 3 Vertebrae Rodent 2 Hindlimb Rodent 1 (maybe 2) Forelimb Rodent 2 Pelvic bone Mole 2 The Skeletal System Post-Lab Questions 1. What types of bones did you recover from the pellet? a. I recovered bones which appear to be from both a rodent, and a mole based on the lab graphic, and my interpretation of the bone. On the rodent skull, and on the jaw pieces, I noted small teeth which was very interesting! 2. Compare the bones you dissected in the owl pellet to human bones. Which bones are similar, which are different, and why? a. The rodent skull was different, but you could still see clearly that is was a skull. This is different than a human skull, because humans have different skull shapes. Pieces of the forelimb and hindlimb resembled human bones, besides the obvious size difference. 3. How can scientists use owl pellets to study the skeletal systems of small mammals in a specific ecosystem? a. Scientists can use the skeletal systems from owl pellets to study different ecosystems, because they can determine geographical differences in skeletal systems hinting at evolution. They would also be able to determine top prey types and compare and contrast other types of prey which are found. Scientists may also be able 4. In addition to owls, other birds of prey produce pellets. The contents of these pellets are dictated by where the bird lives. What would you expect to find in a pellet from a shorebird, such as a gull? a. In a pellet from a shore bird, I would expect to find contents aligning with sea. Fish, sea creatures, or small prey found close to water/shoreland. The Skeletal System EXPERIMENT 4: EFFECTS OF ACID ON BONE Data Tables Table 9: Effect on Pellet Bones Beaker Observations Water Bones still have same appearance as before, no size change. Bones are a bit slimy, but overall, still strong. Vinegar Bones still have same appearance as before, no size or color change. Bones are reduced strength, and more flexible. Post-Lab Questions 1. Which group of bones is more flexible? Why is this so? a. The group of bone which was more flexible were the bones soaked in vinegar. This is because the vinegar caused the bone to reduce strength. 2. What was damaged in the bones placed in vinegar? a. According to this lab, and research, our bones have both calcium carbonate and collagen, calcium carbonate dissolves in vinegar which leads to the reduced strength and structure 3. How might the experiment results vary if the same procedure was performed using bones that had not been regurgitated in an owl pellet (such as raw chicken bones)? a. Based on this lab, I would believe raw chicken bones would react similarly to the regurgitate bones. If they reacted differently, I would relate the change to the consumption and regurgitation process. 4. Some people suffer from a disease called rickets, in which their bones have not been adequately calcified. Which group of bones is most similar to that of a patient with rickets? Why? a. The group of bones most similar to rickets, would be the bones soaked in the vinegar, because theses bones were much weaker compared to the bone soaked in water. The Skeletal System EXPERIMENT 5: PHYSICAL SKELETON – THE AXIAL SKELETON Table 15: Cervical Vertebrae Observations Vertebral Feature Size of cervical vertebrae in comparison to those of the thoracic and lumbar region Observations The cervical vertebra appear to be the smallest of the vertebrae, compared to the thoracic and lumbar regions. The Shape of the vertebral foramen The vertebral foramen is the area housing the spinal cord formed by the vertebral body and arch Spinous process of the C3 – C6 vertebrae The spinous process of C3-C6 are closer in size than C7 C3- C6 have slight appearance of bifid Spinous process of the C7 vertebra The C7 vertebra has the largest spinous process with the longest projection and most prominent bifid Table 16: Thoracic Vertebrae Observations Vertebral Feature Observations Size and weight of the thoracic vertebrae in comparison to those of the cervical and lumbar region The thoracic vertebrae appear to be in the middle for variance of size and projections for all of the regions. The T1-T12 vertebrae appear to start slightly smaller, get larger and then reduce in size again Shape of the vertebral body The shape of the vertebral body is somewhat like a wave, the cervical and lumbar regions are curved outward, and the thoracic region is curved inward Appearance and projection direction of the spinous process The spinous process is projected down and outward, appearing to hover over the next vertebrae The Skeletal System Table 17: Lumbar Vertebrae Observations Vertebral Feature Observations Size of the lumbar vertebrae in comparison to those of the cervical and thoracic region The size of the 5 lumbar vertebrae appear to be larger and bulkier with a larger width. Shape of the vertebral body The shape of the vertebral body is somewhat like a wave, the cervical and lumbar regions are curved outward, and the thoracic region is curved inward Appearance and projection direction of the spinous process The projection of the spinous process are projected posteriorly, and are curved in a downward direction over the next vertebrae Table 18: Rib Feature Observations Rib Feature Observations Length of ribs 1 – 7 (do they increase or decrease in length?) Ribs 1-7 are connected directly to the sternum, so they are longer than ribs 8-12. Ribs 1-7 are considered true ribs, and get bigger (rib 1 smallest) Length of ribs 8 – 12 (do they increase or decrease in length?) Ribs 8-12 are not directly attached to the sternum, instead indreictly attached through the other ribs (1-7) 8-12 get smaller Articulation of the ribs and thoracic vertebrae (notice the specific rib and vertebra that articulate) Each rib articulates with a thoracic vertebrae posteriorly. T1 is rib pair 1, T2 is rib pair 2, etc. The Skeletal System Post-Lab Questions 1. What are the three components of the axial skeleton? Describe the function of each. - The three components of the axial skeleton are o The skull ▪ Function on the skull is to protect and support the brain, ears and eyes o The vertebral column ▪ The function of the vertebral column (also identified as the spinal column) supports and protects the spinal cord, body’s trunk, and other internal organs. o Thoracic cage ▪ The function of the thoracic cage is to support and protect the lungs and heart Identify the labeled components on the skull below. A _____sphenoid bone (orbital)_________ The Skeletal System B _____zygomatic bone __________ C _____mandible bone__________ D ___frontal lobe _____________ E ___supraorbital foramen _____________ F _____vomer bone/ethmoid bone ___________ 5. Indicate whether the following bones are cranial or facial bones, and give their location. Bone Facial or Cranial Location Temporal Bones Cranial bone Mandible Facial bone Vomer Facial bone Zygomatic Bones Facial bone Parietal Bones Cranial bones Ethmoid Bone Sphenoid Bone Lacrimal Bones Cranial bone Cranial bone Facial bone 6. What are the three regions of the vertebral column? Describe the general shape and size of the vertebrae in each region a. The three regions of the vertebral column are The Skeletal System i. Cervical – the vertebrae in this region are shaped with a slight curve and cervical vertebrae are the smallest ii. Thoracic - the vertebrae in this region are shaped in an inward curve and are slightly bigger iii. Lumbar- the vertebrae in this region are shaped with a slight curve and are the largest 7. What are the atlas and axis? What are their functions? The axis is the second cervical (neck) vertebra, and the atlas is the first cervical vertebra. The function of the axis is to support the atlas, working together to turn the head side to side. The function of the atlas is to join the skull and spine and to support movement. The atlas also allows us to nod our head up and down. Identify the vertebral structures on the images below. A __ _lamina_____________ B __ centrum______________ C ____spinous process ____________ The Skeletal System D ____transverse process _______ E ___vertebral foramen _____________ 1. What is the purpose of the thoracic cage? a. The purpose of the thoracic cage is to provide protection for the heart and lungs 2. Describe the three components of the sternum. a. The three components of the sternum are i. The manubrium (top) join the sternum to the clavicles, and first pair of ribs ii. The body (middle, also the longest) where the second ribs attach iii. The xiphiod process (bottom) attaches pericardium 3. Describe the difference between true ribs, false ribs, and floating ribs. a. The difference between true ribs, false ribs, and floating ribs are that true ribs are our normally identified ribs that attach to the sternum (1-7) false ribs are (following 3) are not directly attached to the sternum, instead through cartilage, and the floating ribs (bottom 2) are not attached to the sternum at all EXPERIMENT 6: VIRTUAL MODEL – THE AXIAL SKELETON Post-Lab Questions 1. What features are located inferior to the cranium and superior to the mandible? Identify the category here. How many individual items are included in this category? (Hint: the answer is not a bone.) a. The mouth area (oral cavity) is located in between the cranium and mandible, this area consists of teeth, lips, cheeks, gums, tongue, roof and floor of the mouth 2. Why aren’t teeth considered bones? a. Teeth are not considered bones, because they cannot repair themselves, and they are also exposed to the outside, whereas bones are not. The makeup of teeth vs true bone is also different 3. Identify the two major bones that comprise the head. a. The two bones that make up the head are the cranium and the mandible 4. To what bones does the right scapula attach? a. The right scapula (shoulder) attaches to both the clavicle and the humerus 5. Is the left clavicle superior or inferior to the right scapula? a. The left clavicle would be superior to the right scapula as would the right clavicle to the left scapula The Skeletal System Experiment 7: Physical Skeleton – The Appendicular Skeleton Post-Lab Questions 1. What are the four parts of the upper extremity and the lower extremity of the appendicular skeleton? a. The four appendicular parts of the skeleton are the pectoral girdle, pelvic girdle, upper limbs and lower limbs 2. Compare and contrast the size and function of the upper and lower extremities of the appendicular skeleton. a. The upper extremities do not bear the weight, used for completing tasks/fine motor skills, and are generally smaller than the lower extremities. The lower extremities do bear weight, and in turn are a bit stronger, and larger. The biggest function of the lower limbs is ambulation and overall support 3. What are the three fused bones that make up the coxae of the pelvic girdle? What is their location in relationship to one another? a. The three fused bones making up the coxae are i. Pubic bone in the middle most towards the center ii. Ischium bone on the bottom of the coxae, inferior to the ilium iii. Ilium bone on the top of the coxae, superior to the pubic and ischium Experiment 8: Virtual Model – The Appendicular Skeleton 1. How many left metatarsals are there? a. There are 5 metatarsals on the left foot 2. Is the right fibula inferior or superior to the patella? a. The right fibula is inferior to the patella (knee bone) 3. Which is more proximal to the body: the lunate bone or the medial epicondyle? a. The medial epicondyle is closer to the middle of the body than the lunate bone 4. Which two bones attach to the patella? a. The patella is attached to the femur and tibia 5. Identify the two bones that comprise the leg. a. The two major bones that comprise the leg are the tibia and femur EXPERIMENT 9: ARTICULATIONS Post-Lab Questions 6. In what two ways can joints be classified? What are the three classifications of each type? a. Joints can be classified by their structure of their function i. Classifications for structure are fibrous, cartilaginous or synovial ii. Classifications for function (movement) are synarthroses, amphiarthroses, and diarthroses The Skeletal System 7. Fibrous joints are either sutures or syndesmoses. What is the difference between the two? Give examples of each type. a. Sutures are strong joints between two elements, and do not allow for movement. I.e. skull b. Syndesmoses are fibrous and held together by ligaments, i.e. ankle 8. Symphyses and synchondroses are two classifications of what type of joint? What are the differences between the two classifications? a. Symphyses and synchondroses are both cartilaginous joints, the difference between the two are how they are made up, 9. What allows synovial joints to be diarthrotic? a. A joint capsule allows joints to be diarthrotic Fill in the table below: Joint Articulating Bones Type of Synovial Joint Movement Elbow Humerus and ulna Hinge joint Flexion and extension in one location Knee Patella, femur tibia Hinge joint Flexion and extension in one location Hip Pelvic bone and femur Ball-and-socket joint All movement except gliding Ankle Tibia and fibula Hinge joint Dorsiflexion and plantarflexion Wrist Radius and carpal bones Condyloid joint Allows for flexion, extension, abduction, adduction