Unit 6 Reflection

In this unit, we covered the basics of the skeletal system. Hematopoiesis is the regeneration of blood cells in the bone marrow. Axial bones include 80 bones divided into the skull, vetebral column, and thoracic cage regions. Apendicular bones help humans move around and there are two kinds of bone marrow: red and yellow. Red bone marrow produces blood cells while yellow bone marrow stores energy as fat. Osteoblasts make bone while osteoclasts are bone breakers. In low gravity, osteoclasts increase their rate of bone absorption, while the osteoblasts dial back on the bone formation. Bones are classified by shape: long short, flat, and irregular. Diaphysis is the shaft of a long bone, and is composed of compact bone. Epiphysis is the ends of the bone, and is composed of mostly spongy bone. Periosteum is the outside covering of the diaphysis and is composed of fibrous connective tissue membrane. Sharpey's fibers secure the periosteum to the underlying bone. The arteries supply bone cells with nutrients.


In "Assessment of Stresses in the Cervical Spine Caused by Posture and Position of the Head" by Kenneth K Hansraj, the pressures taken on by the spine are dramatically increased when the head is flexed forward at varying degrees. Good posture is defined as ears aligned with the shoulders and the retracted shoulder blades. Stresses to the cervical spine may result in degeneration and tears. Smartphones and other devices lead to the stresses of the cervical spine. People spend an average of 2-4 hours each day on their phones, hunched over, which contributes to the rising rate of damaged spines.



Bone fractures occur when a bone must take on more stress than it can handle. Complete fractures occur when a bone is broken completely through. Incomplete fractures occur when the fracture does not extend through the bone. Simple fractures occur when the bone does not break through the skin, while a compound fracture involves skin breakage. A comminuted fracture is when a bone is fragmented into 3+ pieces while an oblique fracture is when a bone is broken at an angle. Bone repair may begin when the ends of bone make contact with each other.

During this unit, I feel that I have managed to keep up with my resolutions. My first resolution was to sleep more, and I definitely feel that I have been able to sleep more during this time frame than in first semester. My second resolution is harder to maintain, as I often don't have time to review Anatomy and Physiology notes every single day. In fact, my resolutions sometimes conflict. In order to sleep early, I struggle with reviewing my notes consistently. However, I have been able to maintain my second resolution 60% of the time, which is still significantly better than last semester.

Owl Pellet Analysis/Conclusion

After dissecting the owl pellet, we conclude that the organism consumed by the barn owl was a vole. We discovered multiple scapula in the exact shape of that of a vole's, and we discovered portions of the hip bone. We also found a back leg that contained the tibia and fibula in the exact shape of the vole back legs.








Differences between rodent skeleton and human skeleton:

1. The tibia and fibula are connected on the rodent skeleton. In humans, there are 2 separate bones. 
2. Vertebrae is longer in rodents, because the tail adds extended segments to the vertebral column. 
3. The pelvis of rodents are shaped quite differently than the pelvic girdle of human beings. The rodent hip bone seems to be more elongated. 

Similarities between rodent skeleton and human skeleton:

1. Both rodents and humans have 24 ribs in total and 12 pairs of ribs.  
2. The scapula of both rodents and humans are shaped similarly in a triangular fashion. 
3. The vertebral columns are both made up of small segments (25 pieces).