can be demonstrated by pressing down on a gas pedal or simply standing on one’s toes.
Eversion and inversion are another paired and opposite movement unique to the foot. Eversion is the movement of the sole of the foot away from the midline of the body, which occurs at the subtalar joint, (also called the talocalcaneal joint), more commonly referred to as the ankle. The opposite movement is called inversion, where the sole of the foot is moved toward the midline of the body. Inversion also occurs at the subtalar joint, and excessive or forceful inversion is seen in “twisting the ankle”.
Yet another pair of opposite movements is called protrusion and retrusion. Protrusion is simply any anterior movement of body part, although it is commonly reserved for the forward movement of the mandible, or jaw. Retrusion is the posterior movement of a body part, as in returning the mandible to its normal position after protrusion.
The final pair of opposite movements in our discussion are protraction and retraction. Protraction is the proper anatomical term for the specific anterior movement of the shoulder girdle, whereas retraction (being the opposite) is the anatomical term for the specific posterior movement of the shoulder girdle.
Consequently, we have some movements that do not have clear opposites. Nevertheless, they are specific anatomical movements that require acknowledgement.
Rotation is a movement that occurs when a bone moves around a central axis, without displacing the axis. The bone may rotate around its own longitudinal axis, or the axis of rotation may lie in a completely separate bone, such as in the case of rotating the head in a “no” fashion. In this movement, for example, the point of pivot is formed by the odontoid process of the axis (the second cervical vertebra) around which the atlas (the first cervical vertebra) rotates.
Circumduction is the conical movement of a body part and results from a combination of movements including flexion, extension, abduction, and adduction.
An example of circumduction can be achieved by circling your arms around in a “windmill” fashion, or drawing imaginary circles in the air with your entire leg in extension.
Finally, a highly-specialized type of movement of which the human body is capable is called opposition. This is a grasping motion where the thumb can be pressed against the remaining other four digits of the hand, either altogether (as in the simulation of a “claw hand”) or one digit at a time, as seen when one is physically counting on his/her fingers.
It should also be noted that the above movements do not belong to an all-inclusive or exhaustive list. The movements listed are basically the major types of movements possible across a variety of joints. Furthermore, the above-mentioned movements are often combined at various joints, producing what seems like an infinite variety of motions that can be performed by the human body.
■Conclusion
Anatomy and physiology has been studied for hundreds of years. It is one of the most basic and fundamental, yet imperative courses for anyone studying the human body. The study of the human body’s structure and its function provides a great deal of information for health and medical professionals alike.
The human body is a dynamic, complex, living organism with a wide variety of structures and an even wider breadth of functions. The elementary concepts presented in the overview of human anatomy and physiology is just the beginning to an enormous amount of information. Every student must make a strong effort to thoroughly investigate the basic principles that govern the human body–and anatomy and physiology does just that.
Case Study Conclusion
Upon arrival at the ER, the physician’s main concern is to replace the patient’s blood volume. A fluid bolus is administered, with lung sounds and BP checked every 250 cc until normal range is achieved.
The doctor then orders cervical, spine and chest x-rays with ABGs to determine PaCO2 and PaO2 levels.
He also orders an x-ray of her left femur. No signs of spinal injury are noted. A CT of the head shows no brain trauma or subdural hematomas. While the patient did sustain fractures to ribs 4 and 5 from forceful impact, no signs of splintering are noted. A CT scan confirmed injury to her liver, which caused internal bleeding, hence the low blood pressure (hypotension).
Patient is stabilized and transported to the surgical suite, where her liver was repaired. An orthopedic surgeon was called to address the confirmed transverse midline femoral shaft fracture, which was repaired via external fixation. Deemed superficial, her facial and forearm lacerations were sutured. Following surgery, she was placed in the ICU and monitored for blood clots as well as to reduce risk of development of pulmonary embolism.
Barring any further medical emergencies, patient will be transferred from the ICU to a hospital room to recover. She will then be assessed by a physical therapist who will determine appropriate care plan for ambulatory weight-bearing and mobility.
■Questions
1.Which of the following is the best description of homeostasis?
A.The balance of nutritional compounds that will support a living organism’s optimal function.
B.Stable internal environment comprised of physiologic components including blood pressure, temperature and pH balance.
C.A very simple process of fluid, chemical and blood volume balances.
D.A mechanism that has at least two co-dependent regulatory processes.
Answer: B. Homeostasis is achieved through complex interactions of checks and balances in the body able to adapt to and compensate for ever-changing physiological interactions that regulate numerous body functions and processes.
Learning Objective: 3
2.Define the difference between gross and microscopic anatomy.
A.Gross anatomy is the study of muscles while microscopic anatomy is the study of molecular structures.
B.Gross anatomy is basically visible to the naked eye while microscopic anatomy is the study of structures in the body invisible to the naked eye.
C.Gross anatomy defines dissection of the body while microscopic anatomy defines anything that is observed under the microscope.
D.Gross anatomy is the study of living organisms while microscopic anatomy is the study of how organ systems work.
Answer: B. Gross anatomy is the study of any area of the body visible to the naked eye; bone, muscle, or an organ for example, while microscopic anatomy pertains to cells and structures or even functions of an organ only visible through microscopic viewing or analysis.
Learning Objective: 1
3.Define the overall purpose of anatomical terminology and positioning for medical personnel.
A.Ensures a static and scientific method that is used around the world to correctly ascertain anatomical positioning, i.e. anterior/posterior or proximal/distal to denote precise physical position.
B.It’s a process that is used in the U.S. that divides the body into upper and lower sections for easier study by medical students.
C.Anatomical terminology changes with physiological aspects of the body caused by changes in any of the body’s organisms and aids in diagnostics.
D.Anatomical
