Muscle structure and function

Muscles and Action肌肉和活动1Muscle, the raw material of movement, is a contractile tissue that makes up from 35 to 45 per cent of the body’s weight and powers all its actions – from the merest flicker of an eyelid to the sustained effort needed to run a marathon race. 2Even during sleep some muscles remain active in order to power vital support systems.1肌肉—运动的原材料—是一种有收缩力的组织，占体重的35%~45%，为身体所有活动提供动力：从一眨眼道跑马拉松所需的持久的努力。

2甚至在睡眠时，为了给极为重要的支持系统提供动力，有些肌肉仍保持活动状态。

1There are three types of muscle, all different in structure and function. 2Skeletal muscle – the meat on our bones – is strongest and most abundant. Smooth muscle, found in the arteries, intestines, and other internal organs, performs slow, sustained contractions. 3Cardiac muscle is specific to the heart, generating the powerful contractions that pump blood.1肌肉有三种类型，结构和功能各异。

骨骼肌的构造分类和辅助结构英文回答：Skeletal muscles are classified based on theirstructure and function. Structurally, skeletal muscles can be classified into three types: parallel, pennate, and convergent muscles.Parallel muscles are characterized by long, parallel muscle fibers that run in the same direction as themuscle's action. These muscles are typically found in the limbs and are responsible for producing large, powerful movements. An example of a parallel muscle is the biceps brachii in the upper arm.Pennate muscles, on the other hand, have shorter fibers that are arranged at an angle to the tendon. This arrangement allows for a greater number of muscle fibers to be packed into a smaller space, resulting in increased strength. Pennate muscles are further classified asunipennate, bipennate, or multipennate, depending on the angle of the muscle fibers. An example of a pennate muscle is the rectus femoris in the thigh.Convergent muscles have a broad origin that converges into a single tendon. These muscles are versatile and can produce a variety of movements depending on which fibers are activated. An example of a convergent muscle is the pectoralis major in the chest.In addition to their structural classification, skeletal muscles also have various auxiliary structures that assist in their function. These include tendons, aponeuroses, and fasciae.Tendons are tough, fibrous connective tissues that attach muscles to bones. They transmit the force generated by the muscle to the bone, allowing for movement. For example, the Achilles tendon connects the calf muscles to the heel bone and enables plantar flexion of the foot.Aponeuroses are similar to tendons but are flat andsheet-like in structure. They serve as attachment sites for muscles and help to distribute the force generated by the muscle over a larger area. An example of an aponeurosis is the linea alba, which runs down the midline of the abdomen and provides attachment for the abdominal muscles.Fasciae are connective tissues that surround and separate muscles, providing support and allowing for smooth movement. They also contain blood vessels and nerves that supply the muscles. An example of a fascia is the plantar fascia in the foot, which helps to maintain the arch of the foot and absorb shock during walking or running.In conclusion, skeletal muscles can be classified based on their structure into parallel, pennate, and convergent muscles. These muscles are supported by auxiliarystructures such as tendons, aponeuroses, and fasciae, which play important roles in their function.中文回答：骨骼肌根据其结构和功能可以分为不同类型。

Mammalian Skeletal Muscle Tissue Sample Mammalian skeletal muscle tissue is a fascinating and complex structure that plays a crucial role in our everyday lives. From allowing us to move and perform physical activities to maintaining our posture and supporting our skeletal system, skeletal muscle tissue is an integral part of our body. In this response, I will explore the various aspects of mammalian skeletal muscle tissue, including its structure, function, and importance. First and foremost, let's delve into the structure of mammalian skeletal muscle tissue. Skeletal muscles are composed of long, cylindrical cells called muscle fibers. These fibers are multinucleated and contain specialized structures called myofibrils, which are responsible for muscle contraction. Myofibrils consist of repeating units called sarcomeres, which are the functional units of skeletal muscle tissue. Each sarcomere contains thick and thin filaments, composed of the proteins myosin and actin, respectively. The interaction between these filaments allows for the sliding filament mechanism, which is responsible for muscle contraction. Moving on to the function of mammalian skeletal muscle tissue, it is primarily responsible for voluntary movements. Skeletal muscles are under conscious control, allowing us to perform a wide range of activities such as walking, running, and lifting objects. Muscle contraction occurs when nerve impulses from the brain stimulate the muscle fibers, causing the myosin and actin filaments to slide past each other, resulting in muscle shortening and movement. Additionally, skeletal muscle tissue also plays a role in maintaining body temperature and providing stability and support to our skeletal system. The importance of mammalian skeletal muscle tissue cannot be overstated. Without it, we would be unable to perform even the simplest of tasks. From the moment we wake up in the morning and get out of bed to the activities we engage in throughout the day, skeletal muscle tissue is constantly at work. It allows us to walk, run, jump, and perform various physical activities that are essential for our overall well-being. Furthermore, skeletal muscle tissue also contributes to our metabolism by burning calories and helping to maintain a healthy body weight. From a physiological perspective, skeletal muscle tissue is a highly adaptable tissue. It has the ability to undergo hypertrophy, which is an increase in muscle fiber size, in response to regular exercise and physicalactivity. This adaptation allows the muscle tissue to become stronger and more efficient in performing tasks. On the other hand, a lack of physical activity can lead to muscle atrophy, which is a decrease in muscle fiber size. This highlights the importance of regular exercise in maintaining healthy skeletal muscle tissue. In conclusion, mammalian skeletal muscle tissue is a remarkable structure that enables us to perform a wide range of activities. Its complex structure,consisting of muscle fibers, myofibrils, and sarcomeres, allows for muscle contraction and movement. The function of skeletal muscle tissue extends beyond voluntary movements, as it also contributes to body temperature regulation and provides support to our skeletal system. The importance of skeletal muscle tissuein our daily lives cannot be underestimated, as it allows us to engage in physical activities and maintain a healthy body weight. Regular exercise is crucial for the maintenance and adaptation of skeletal muscle tissue, highlighting its dynamic nature. Overall, mammalian skeletal muscle tissue is a vital component of our body, allowing us to lead active and fulfilling lives.。

肌肉英语翻译Muscle tissues are classified into three types: skeletal, cardiac, and smooth muscle. Each type of muscle has its own unique structure and function.Skeletal muscle, also known as striated muscle, is attached to bones and is responsible for voluntary movements. It is made up of long, cylindrical cells called muscle fibers. These fibers are multinucleated, meaning they have more than one nucleus. Skeletal muscle fibers are striated due to the arrangement of contractile proteins, actin, and myosin. When these proteins slide past each other, the muscle contracts, resulting in movement.Cardiac muscle is found only in the heart and is responsible for pumping blood throughout the body. It is also striated, like skeletal muscle, but has some unique features. Cardiac muscle fibers are branched and connected by specialized junctions called intercalated discs. These discs allow for rapid transmission of electrical impulses, ensuring coordinated contractions of the heart. Unlike skeletal muscle, cardiac muscle is involuntary, meaning it contracts without conscious control.Smooth muscle is found in the walls of hollow organs, such as the stomach, intestines, and blood vessels. Unlike skeletal and cardiac muscle, smooth muscle is not striated. Smooth muscle cells are spindle-shaped and contain only one nucleus. Smooth muscle is involuntary and contracts slowly and rhythmically. It is responsible for various functions, such as regulating organ diameter, moving substances through the digestive tract, and controlling blood pressure.Muscles have several key properties that allow them to function effectively. Excitability refers to the ability of muscle cells to respond to stimuli, such as chemical signals or electrical impulses. Contractibility is the ability of muscles to shorten and generate force when stimulated. Extensibility refers to the ability of muscles to stretch without being damaged. Lastly, elasticity is the ability of muscles to return to their original shape after being stretched.Muscles work in pairs or groups to produce movements. When one muscle contracts, its counterpart relaxes, allowing for smooth and coordinated movements. Muscles are attached to bones by tendons, which are strong, fibrous connective tissues. When a muscle contracts, it pulls on the attached bone, resulting in movement.Regular exercise is essential for maintaining muscle health and function. Exercise promotes muscle growth and strength through a process called hypertrophy. During exercise, muscles are repeatedly subjected to stress, causing small tears in the muscle fibers. In response, the body repairs and strengthens the muscles, resulting in increased size and strength. Additionally, exercise improves muscle endurance by increasing the number of capillaries and mitochondria, which supply oxygen and energy to the muscles. In conclusion, muscles play a crucial role in providing movement, stability, and support to the body. There are three types of muscles: skeletal, cardiac, and smooth muscle, each with its own unique properties and functions. Regular exercise is necessary to maintain the health and strength of muscles.。

muscles英文搭配The Role and Importance of Muscles in the Human Body.Muscles are a crucial component of the human body, playing a pivotal role in almost every function we perform. They are responsible for movement, posture, and even some internal functions like heartbeat and breathing. Understanding the structure, function, and importance of muscles is essential for maintaining a healthy and active lifestyle.Types of Muscles.There are three main types of muscles in the human body: skeletal, smooth, and cardiac.1. Skeletal Muscles: These are the muscles we are most familiar with as they are attached to the bones and allowus to move. They are voluntary muscles, meaning we can control their contraction. Skeletal muscles are furtherclassified into three types based on their shape and function: fusiform, strap, and pennate.2. Smooth Muscles: These muscles are found in the walls of organs like the intestines, uterus, and blood vessels. They are involuntary, meaning we cannot control their contraction directly. Smooth muscles contract slowly and rhythmically to perform functions like digestion and blood flow.3. Cardiac Muscles: These muscles make up the heart and are responsible for pumping blood throughout the body. They are involuntary and contract rhythmically to maintain a steady heartbeat.Functions of Muscles.Muscles perform a wide range of functions in the human body, including:Movement: Skeletal muscles allow us to move our limbs, trunk, and neck. They contract to create force and movement,enabling us to perform activities like walking, running, lifting, and reaching.Posture and Balance: Muscles work together to maintain our posture and balance. They contract to keep us upright and prevent us from falling over.Internal Functions: Smooth muscles play a crucial role in internal functions like digestion, respiration, and blood flow. They contract to move food through the intestines, expand and contract the lungs to allow breathing, and regulate blood pressure by constricting or dilating blood vessels.Heat Production: Muscles also play a role in heat production. When we contract muscles, they generate heat as a by-product of metabolism. This heat helps maintain our body temperature in cold environments.Importance of Muscles.The importance of muscles cannot be overstated. Theyare essential for maintaining a healthy and activelifestyle. Here are some reasons why muscles are crucial:Physical Activity: Muscles allow us to performphysical activities, which is essential for maintaininggood health. Regular exercise strengthens muscles, improves cardiovascular health, and reduces the risk of chronic diseases like obesity and diabetes.Posture and Balance: Strong muscles help maintain good posture and balance, reducing the risk of falls andinjuries. Good posture also improves breathing and digestion.Body Composition: Muscles are a crucial component of body composition. Having a higher muscle mass improves body image and can lead to a more toned and defined appearance.Metabolism: Muscles play a key role in metabolism.They consume calories when contracting, which helpsmaintain a healthy weight and prevent obesity. Additionally, muscle mass is more metabolically active than fat mass,meaning it requires more calories to maintain.Protection: Muscles provide protection for internal organs. They cushion and support organs like the spine, kidneys, and intestines, reducing the risk of injury.Conclusion.Muscles are an integral part of the human body, performing a wide range of functions that are essential for maintaining good health and an active lifestyle. Understanding the structure, function, and importance of muscles is crucial for taking care of our bodies and preventing injuries. Regular exercise and a balanced diet are essential for maintaining strong and healthy muscles.。

Histology and Embryology（组织学与胚胎学）IntroductionHistology and embryology are branches of biology that deal with the study of tissues and embryonic development, respectively. Histology is the study of the microscopic structure of tissues, including their organization and function. Embryology, on the other hand, is the study of the development of an embryo from a fertilized egg cell to a fully-formed organism.HistologyHistology is the study of the microscopic structure of tissues. Tissues are groups of cells that perform a specific function in the body. The human body is made up of four basic tissue types: epithelial, connective, muscle, and nervous tissue. Each of these tissue types has a unique structure and function.Epithelial tissue is found on the surface of the body and in the lining of organs, such as the gut and lungs. It is composed of tightly-packed cells that form a barrier between the body and the external environment. Epithelial tissue also helps to absorb nutrients, secrete hormones, and protect the body from harmful substances.Connective tissue supports and connects other tissues and organs in the body. It includes structures such as bone, cartilage, and tendons. Connective tissue is also found in the skin, where it forms the connective tissue layer known as the dermis.Muscle tissue is found in the heart, skeletal muscles, and smooth muscle. Muscle tissue is responsible for movement and is capable of generating force to move the body.Nervous tissue is used for communication and coordination in the body. It includes the brain, spinal cord, and peripheral nerves. Nervous tissue is made up of specialized cells called neurons, which transmit electrical impulses to other cells in the body.EmbryologyEmbryology is the study of the development of an embryo from a fertilized egg cell to a fully-formed organism. The development of an organism is a complex process that involves many stages, including fertilization, cleavage, gastrulation, and organogenesis. Fertilization occurs when a sperm cell and an egg cell combine to form a zygote. The zygote undergoes multiple rounds of cell division in a process called cleavage. During cleavage, the cells become smaller and more numerous, but do not increase in size.Gastrulation is the process by which the three germ layers (endoderm, mesoderm, and ectoderm) are formed. The endoderm gives rise to the digestive and respiratory systems, the mesoderm gives rise to the musculoskeletal system, and the ectoderm gives rise to the skin, nervous system, and sensory organs. Organogenesis is the process by which organs and organ systems are formed. During this process, cells differentiate and become specialized to perform specific functions. For example, cells in thepancreas differentiate and become specialized to secrete insulin, a hormone that regulates blood sugar levels in the body.Applications of Histology and EmbryologyHistology and embryology have many applications in the fields of medicine and biology. These fields include:1. Medical Diagnosis: Histology is used to diagnose diseases such as cancer. Tissue samples are taken from a patient and examined under a microscope to determine if cancer cells are present. Embryology is also used to diagnose genetic disorders in embryos before birth.2. Drug Development: Histology is used to study the effects of drugs on different tissues in the body. This helps pharmaceutical companies develop new medications that are safe and effective.3. Developmental Biology: Embryology is used to study the development of organisms and to understand how different genetic and environmental factors affect the development of an embryo.4. Tissue Engineering: Histology and embryology are used to study how cells interact with each other and with the extracellular matrix. This helps researchers develop new methods for growing tissues and organs in the laboratory for use in transplants.ConclusionIn conclusion, histology and embryology are two importantbranches of biology that have many applications in medicine and biology. Histology is the study of the microscopic structure of tissues, while embryology is the study of the development of an embryo from a fertilized egg cell to a fully-formed organism. These fields are essential for understanding the structure and function of tissues and organs in the body, and for developing new treatments for es of Histology and Embryology in MedicineAs mentioned earlier, histology and embryology are used extensively in medicine for a wide range of purposes. The following are some of the areas where these fields play an essential role in medicine:Medical DiagnosisHistology is used to diagnose different types of diseases, including cancers. Doctors can take a small tissue sample, commonly called a biopsy, from a patient to examine it under a microscope. The use of histology for diagnostic purposes is called 'histopathology.'Histopathology provides a detailed analysis of the tissue structure, which enables doctors to identify any abnormalities. Doctors can look for signs of cancer, inflammation, and other conditions by examining tissue samples.Additionally, immunohistochemistry (IHC) techniques are used to identify specific proteins in tissue samples. This works by using antibodies that attract to specific proteins in the sample and coat the tissue, highlighting the proteins in question. Based on thesefindings, doctors can diagnose the specific type of cancer or other conditions and recommend appropriate treatment options.Drug DevelopmentHistology is used extensively in drug development to study the effects of drugs on different tissue types. Medical researchers test new medications on tissue samples to determine their safety and effectiveness.By studying the effects of the drugs on tissues, researchers can determine any potential risks and develop safe medications. Moreover, histology is also used to study the toxicity of a substance and identify safe therapeutic doses accurately. The information from histology samples is used to fine-tune the drug development process, from preclinical to clinical trials, to ensure the drugs are efficacious and safe to use.Developmental BiologyEmbryology is integral to the study of developmental biology, which is the process of understanding how embryos develop into mature organisms. Researchers use embryonic cells to study the mechanisms involved in the formation of different organs and tissues.This research can help understand the interaction between genes and environmental factors and identify the genes involved in the development of specific organs. Embryology also provides critical insights into the cause of developmental disorders and geneticdiseases.Tissue EngineeringTissue engineering is a cutting-edge field in which researchers develop techniques to regrow or reconstruct tissues and organs that have been damaged or lost due to injury or disease. Histology and embryology techniques are essential for researching cell interactions and developing methods to grow functional tissues and organs.Researchers study how cells grow and interact with each other and extracellular matrix with histology and embryology. This research helps to develop new methods for growing tissues and organs in a laboratory setting, which can eventually be used for transplantation. Advancements in tissue engineering have led to the developmentof a range of medical treatments and therapies, including artificial skin, blood vessels, and even synthetic heart valves. In the near future, researchers hope to grow fully functional complex organs like the kidney or heart through the application of innovative tissue engineering techniques.Uses of Histology and Embryology in BiologyHistology and embryology have several uses in biology and related fields. Some of the main uses and applications are as follows:Cell BiologyHistology plays a crucial role in cell biology, mainly because it enables researchers to study the structure and function of different cells in detail. Cell biology involves understanding the fundamental characteristics of cells, including how they grow, divide, interact, and ultimately function.Histology enables researchers to identify and analyze different cell types and structures. For example, researchers may use histology techniques to identify the different cell types in neural tissue, including neurons, glial cells, and other supporting structures.Evolutionary BiologyEmbryology is essential in the study of evolutionary biology because it provides insights into how different organisms developed from a common ancestry. By examining the various stages of embryonic development, researchers can identify and compare traits across multiple species, looking for similarities and differences.This research has provided insights into the evolutionary origins of various life forms, which have helped to inform ecological conservation efforts. Understanding the evolutionary relationships of different species can inform conservation plans and aid in the preservation of life on Earth.GeneticsGenetics is another field that utilizes embryology. As we know, the development of an embryo involves the expression of specificgenes, which determine the characteristics that the embryo will inherit.By studying the genetic processes occurring during embryonic development, researchers can identify potential genetic disorders that can arise during embryonic development or identify genetic markers associated with various illnesses. Moreover, researchers include the study of genetic variation throughout embryonic development to enhance our understanding of genetic inheritance.ConclusionIn conclusion, histology and embryology are two essential branches of biology with numerous applications in the fields of medicine and biology. Histology involves the study of microscopic structures of tissues, while embryology entails the study of embryonic development. The use of these sciences has far-reaching impacts in medical diagnosis, drug development, and tissue engineering. Additionally, in biology, histology and embryology help to understand cell biology, evolutionary relationships, and genetic inheritance.It is without a doubt that continuing advances in these fields will continue to contribute to our scientific understanding and provide insights into the intricate workings of life.。

肌肉神经系统介绍英语作文The Muscular and Nervous SystemsThe human body is a complex and intricate system, composed of numerous interdependent structures and functions. Two of the most important systems in the body are the muscular system and the nervous system. These two systems work together to facilitate movement, sensation, and overall bodily function.The muscular system is composed of three main types of muscle: skeletal, cardiac, and smooth. Skeletal muscles are attached to bones by tendons and are responsible for voluntary movement. These muscles come in a variety of shapes and sizes, and are located throughout the body, from the small muscles in the fingers to the large muscles in the legs and back. Cardiac muscle is found only in the heart and is responsible for the rhythmic contraction and relaxation of the heart, pumping blood throughout the body. Smooth muscle is found in the walls of internal organs, blood vessels, and other structures, and is responsible for involuntary movements such as the peristalsis of the digestive system.Muscles work by contracting and relaxing in response to signals fromthe nervous system. The nervous system is divided into two main parts: the central nervous system (CNS) and the peripheral nervous system (PNS). The CNS is composed of the brain and spinal cord, and is responsible for processing and interpreting information, as well as coordinating the body's overall function. The PNS is made up of the nerves that extend from the CNS to the rest of the body, transmitting information and signals between the brain and the rest of the body.When the brain sends a signal to a muscle, the signal travels through the PNS to the muscle fibers, causing them to contract. This contraction produces movement, which is the basis of all voluntary and involuntary movement in the body. The nervous system also plays a crucial role in the sensation of touch, temperature, pain, and other stimuli, as well as in the regulation of autonomic functions such as breathing, heart rate, and digestion.The muscular and nervous systems work together in a complex and coordinated way to allow the body to function effectively. For example, when you reach for an object, the brain sends a signal through the PNS to the muscles in your arm and hand, causing them to contract and move the limb. The muscles then provide feedback to the brain through the PNS, informing it of the position and movement of the limb.This feedback loop is essential for fine motor control andcoordination, as the brain can use the information from the muscles to make adjustments and fine-tune the movement. Similarly, the nervous system is responsible for the sensation of touch and pressure in the muscles, which is important for proprioception (the sense of the body's position and movement in space) and for the coordination of movement.The muscular and nervous systems are also closely linked to other body systems, such as the skeletal system and the cardiovascular system. For example, the muscles require a steady supply of oxygen and nutrients to function, which is provided by the cardiovascular system. The skeletal system, on the other hand, provides the structure and support for the muscles, allowing them to generate movement.In conclusion, the muscular and nervous systems are two of the most important systems in the human body, working together to facilitate movement, sensation, and overall bodily function. The complex interplay between these two systems is essential for our ability to interact with the world around us and to maintain our health and well-being.。

Chapter 1Passage 1 Human BodyIn this passage you will learn:1. Classification of organ systems2. Structure and function of each organ system3. Associated medical termsTo understand the human body it is necessary to understand how its parts are put together and how they function. The study of the body's structure is called anatomy; the study of the body's function is known as physiology. Other studies of human body include biology, cytology, embryology, histology, endocrinology, hematology, immunology, psychology etc.了解人体各部分的组成及其功能，对于认识人体是必需的。

研究人体结构的科学叫解剖学；研究人体功能的科学叫生理学。

其他研究人体的科学包括生物学、细胞学、胚胎学、组织学、内分泌学、血液学、遗传学、免疫学、心理学等等。

Anatomists find it useful to divide the human body into ten systems, that is, the skeletal system, the muscular system, the circulatory system, the respiratory system, the digestive system, the urinary system, the endocrine system, the nervous system, the reproductive system and the skin. The principal parts of each of these systems are described in this article.解剖学家发现把整个人体分成骨骼、肌肉、循环、呼吸、消化、泌尿、内分泌、神经、生殖系统以及感觉器官的做法是很有帮助的。