Name The Characteristics Of The Three Types Of Muscles
Dear Students: Please answer the following questions: 1.- Please name the characteristics of the three types of muscles. 2.- Please explain the following characteristics in a muscle: Excitability, Contractility, Extensibility, Elasticity. 3.- What is epimysium, perimysium, and endomysium? 4.- a) Please explain what is sarcomere? b) Thin filaments contain: __________________________________ 5.- Please explain the sliding – filament theory. 6.- a) Why are important the intercalated discs or Gap junctions in the myocardium? b) Please explain the blood flow through the heart and the lungs, naming all the structures. 7.- a) Why are important the Sinoatrial node (SA), and the Atrioventricular node (AV)? b) What means systole and diastole in cardiac cycle? 8.- Please explain the following concepts: automaticity, cardiac output, stroke volume, and ejection fraction. 9.- a) Please name the branches of the aortic arch. b) Please name the branches of the celiac trunk. 10.- a) Please name the parts of the aorta. b) Please name the blood vessels that bring blood to the liver. The Second Written Assignment, due November 13, is an analysis of a case study about ethical leadership. You may select any of the case studies in our text edited by Dr. Patricia Mitchell. Summarize the main points of the case, and then provide answers to the questions in paragraph form. You may certainly add comments and analysis beyond responses to the questions. The paper should be a minimum of 4 pages in length, typed double-spaced. APA format Double Space 4 or more pages Times New Roman Font size 12 Case Study: A Bully or Just Doing the Job? Author Silvia Ramirez Book case study is in: Ethical Decision Making Cases in Organization and Leadership Edited by Patricia A. Mitchell SUMMARIZE MAIN POINTS ANSWER EACH OF THESE QUESTIONS AFTER SUMMARIZING THE MAIN POINTS 1. Did Ginger act qthically by not imforming the teachers that changes were coming in the district? 2. Did the teachers need to know what to expect from the handbook to comply with the changes? 3. Was Ginger really a bully or just doing her job? 4. What leadership lessons were Learned? image.jpg image2.jpg
name the characteristics of the three types of muscles Characteristics of the three types of muscles
Understanding the main characteristics of the three types of muscles—skeletal, cardiac, and smooth—is fundamental in appreciating their distinct roles in human physiology. Skeletal muscles are voluntary muscles primarily responsible for body movements. They are characterized by their striated appearance, multinucleated cells, and the ability to contract rapidly and forcefully, but they fatigue relatively quickly. Cardiac muscles, found only in the heart, are also striated but are involuntary. These muscles possess unique features such as intercalated discs that allow synchronized contractions and endurance for continuous activity. Smooth muscles make up the walls of internal organs like the intestines and blood vessels; they are non-striated, involuntary, and capable of sustained contractions, which are essential for regulating internal processes like blood flow and digestion.
Characteristics of Muscle Types
Skeletal Muscle
Skeletal muscles are voluntary, striated, multinucleated, capable of quick contractions, and fatigue easily. They tend to be large and attached to bones via tendons, facilitating movement.
Cardiac Muscle
Cardiac muscle is involuntary, striated, has one or two centrally located nuclei per cell, and features intercalated discs that enable synchronized contractions. It is highly resistant to fatigue.
Smooth Muscle
Smooth muscle is involuntary, non-striated, with a single central nucleus. It contracts slowly and can sustain contractions for extended periods, crucial in organs like the stomach, intestines, and blood vessels.
Muscle Characteristics Explained
Excitability refers to a muscle's ability to respond to a stimulus, typically a nerve impulse. Contractility is the capacity to shorten forcibly when stimulated, leading to movement or tension generation. Extensibility is the muscle's ability to stretch without damage, allowing it to accommodate increased volume or lengthening. Elasticity is the tendency of a muscle to return to its original shape after being stretched or contracted. These properties are essential for proper muscle function and coordination in the body.
Muscle Structures: Epimysium, Perimysium, Endomysium
The epimysium is a dense connective tissue layer encapsulating an entire muscle, providing structural support and protection. Inside the muscle, the perimysium surrounds fascicles—bundles of muscle fibers—serving as a pathway for blood vessels and nerves. The endomysium is a thin connective tissue layer surrounding individual muscle fibers, aiding in the exchange of nutrients and waste between blood vessels and muscle cells.
Sarcomere and Thin Filaments
a) The sarcomere is the basic functional unit of striated muscle fibers, responsible for muscle contraction. It is delineated by Z-discs and contains organized arrangements of thick and thin filaments that slide past each other during contraction.
b) Thin filaments contain actin, along with regulatory proteins such as tropomyosin and troponin that control muscle contraction.
Sliding-Filament Theory
The sliding-filament theory explains muscle contraction as the sliding of thin (actin) filaments past thick (myosin) filaments within the sarcomere. When a muscle receives a stimulus, myosin heads attach to actin, forming cross-bridges and pulling the thin filaments toward the center of the sarcomere. This shortening of the sarcomere leads to muscle contraction. The process is powered by ATP and regulated by calcium ions, which enable the interaction between actin and myosin.
Myocardial Intercalated Discs, Blood Flow, and Cardiac Nodes
a) Intercalated discs and gap junctions are crucial in myocardium for synchronized contraction of cardiac muscle cells, allowing the heart to function as a coordinated unit.
b) Blood flow begins in the vena cavae into the right atrium, proceeds to the right ventricle, then through the pulmonary artery to the lungs for oxygenation. Oxygenated blood returns via pulmonary veins to the left atrium, passes into the left ventricle, and is pumped through the aorta to the systemic circulation, delivering blood to all tissues.
Electrical Conduction System of the Heart
a) The sinoatrial (SA) node acts as the pacemaker of the heart, initiating electrical impulses that set the rhythm. The atrioventricular (AV) node receives signals from the SA node and relays them to ensure coordinated atrial and ventricular contractions.
b) During systole, the heart contracts to pump blood out; during diastole, it relaxes to fill with blood. These phases are vital in maintaining effective circulation.
Cardiac Concepts: Automaticity, Output, Stroke, Ejection
Automaticity is the heart's ability to generate its own electrical impulses without external stimuli. Cardiac output refers to the volume of blood the heart pumps per minute, a product of heart rate and stroke volume. Stroke volume is the amount of blood ejected by the ventricle in one contraction. Ejection fraction measures the percentage of blood ejected from the ventricle during systole, indicating cardiac efficiency.
Major Arteries and Vasculature
Branches of the Aortic Arch
The aortic arch gives rise to three major arteries: the brachiocephalic trunk (which bifurcates into the right subclavian and right common carotid arteries), the left common carotid artery, and the left subclavian artery.
Branches of the Celiac Trunk
The celiac trunk supplies the upper abdominal organs and branches into the left gastric, splenic, and common hepatic arteries.
Aorta and Hepatic Blood Supply
b) The parts of the aorta are the ascending aorta, aortic arch, thoracic aorta, and abdominal aorta.
The blood vessels supplying the liver include the hepatic artery (from the celiac trunk for oxygenated blood) and the portal vein (carrying nutrient-rich blood from the gastrointestinal tract).
Analysis of Ethical Leadership Case Study
The case study "A Bully or Just Doing the Job?" by Silvia Ramirez in the book "Ethical Decision Making Cases in Organization and Leadership" explores complex issues surrounding ethical decision-making within organizational leadership. The main focus is on Ginger, a manager who implements policy changes without informing teachers, raising questions about her ethicality, leadership style, and the implications for team dynamics.
Ginger's decision not to inform teachers about upcoming district changes raises ethical concerns about transparency and honesty. Ethically, leadership involves open communication and respecting employees' rights to be informed about decisions that impact their work. By withholding information, Ginger may have compromised trust and morale among her team. Teachers need to understand the changes to adapt their practices accordingly, making transparency vital for compliance and effective implementation.
Regarding whether Ginger was a bully or just doing her job, the analysis suggests that her actions lean more towards authoritarian behavior, possibly bordering on bullying if her motivations were solely to enforce policy without regard for staff concerns. However, from a leadership perspective, she might have been fulfilling her responsibilities without malicious intent, indicating a complex balance between managerial authority and ethical conduct.
Leadership lessons from this case emphasize the importance of ethical communication, transparency, and employee engagement. Leaders should foster environments where open dialogue is encouraged, and changes are communicated effectively to uphold trust and morale. The case highlights the necessity of balancing organizational goals with ethical responsibilities, ensuring that leadership actions contribute positively to organizational culture.
References
- Mitchell, P. A. (Ed.). (2015). Ethical Decision Making Cases in Organization and Leadership. Sage Publications.
- Ramirez, S. (Year). A Bully or Just Doing the Job? [Case study]. In P. A. Mitchell (Ed.), Ethical Decision Making Cases in Organization and Leadership.
- Gini, M. (2017). Ethics in Leadership. Routledge.
- Brown, M. E., & Treviño, L. K. (2006). Ethical leadership: A review and future directions. The Leadership Quarterly, 17(6), 595-616.
- Resick, C. J., & Falcetta, J. M. (2009). Ethical leadership: Developing a model of moral efficacy. The Leadership Quarterly, 20(2), 331-345.
- Northouse, P. G. (2018). Leadership Theory and Practice (8th ed.). Sage Publications.
- Ciulla, J. B. (2004). Ethics and Leadership Effectiveness. In K. S. Cameron & G. M. Spreitzer (Eds.), The Oxford Handbook of Positive Organizational Scholarship. Oxford University Press.
- Bass, B. M., & Steidlmeier, P. (1999). Ethics, character, and authentic transformational leadership behavior. The Leadership Quarterly, 10(2), 181-217.
- Kidder, R. M. (2005). Moral Courage: Confronting Challenges to Our Moral Integrity. HarperOne.
- Yukl, G. (2013). Leadership in Organizations (8th ed.). Pearson.