a) List out any two differences between striated muscle and cardiac muscle
with respect to
Dendron
Somalce
Nucleus
Axon
Myelin
Axon ter
Atheir structure and location.
b) Identify above diagram and write structure location and function of this tissue
Answers
Answer:
Muscular tissue is the third of the four major categories of animal tissue. Muscle tissue is subdivided into three broad categories: skeletal muscle, cardiac muscle, and smooth muscle. The three types of muscle can be distinguished by both their locations and their microscopic features.
Skeletal muscle is found attached to bones. It consists of long multinucleate fibers. The fibers run the entire length of the muscle they come from and so are usually too long to have their ends visible when viewed under the microscope. The fibers are relatively wide and very long, but unbranched. Fibers are not individual cells, but are formed from the fusion of thousands of precursor cells. This is why they are so long and why individual fibers are multinucleate (a single fiber has many nuclei). The nuclei are usually up against the edge of the fiber. There are striations in skeletal muscle. These are alternating dark and light bands perpendicular to the edge of the fiber that are present all along the fiber.
Cardiac muscle is only found in the heart. Its fibers are longer than they are wide, and they are striated, like skeletal muscle fibers. But, unlike skeletal muscle fibers, cardiac muscle fibers have distinct ends to them, called intercalated discs. These are dark lines that run from one side of the fiber to the other. The intercalated discs are not much thicker than the striations, but they are usually darker and so distinct for that reason. One cardiac muscle fiber is the material between two intercalated discs. Cardiac muscle fibers are mononucleate, with only one nucleus per fiber, and they can sometimes be branched.
Smooth muscle is found in the walls of internal organs, such as the organs of the digestive tract, blood vessels, and others. It consists of mononucleate fibers with tapered edges. No striations are visible in smooth muscle under the microscope. Because smooth muscle often is wrapping around the organ it is associated with, it can be hard to find an entire smooth muscle fiber in profile in a tissue slice on a microscope slide. Most of the fibers will be sectioned at angles or will be difficult to get into a single plane of focus, but a little bit of searching can usually turn up some with all of the defining characteristics visible.
LAB 5 EXERCISES 5.6
In each of the three photomicrographs below, identify which type of muscle is present. List the defining visual characteristics of that type of muscle, and draw arrows to features on the photograph that illustrate each characteristic.
cardiac_muscle
skeletal_muscle
smooth_muscle
Explanation:
Cardiac muscle (also called heart muscle or myocardium) is one of three types of vertebrate muscles, with the other two being skeletal and smooth muscles. It is an involuntary, striated muscle that constitutes the main tissue of the walls of the heart. The myocardium forms a thick middle layer between the outer layer of the heart wall (the epicardium) and the inner layer (the endocardium), with blood supplied via the coronary circulation. It is composed of individual heart muscle cells (cardiomyocytes) joined together by intercalated discs, encased by collagen fibers and other substances that form the extracellular matrix.
Cardiac muscle contracts in a similar manner to skeletal muscle, although with some important differences. Electrical stimulation in the form of an action potential triggers the release of calcium from the cell's internal calcium store, the sarcoplasmic reticulum. The rise in calcium causes the cell's myofilaments to slide past each other in a process called excitation contraction coupling.
Diseases of the heart muscle are of major importance. These include conditions caused by a restricted blood supply to the muscle including angina pectoris and myocardial infarction, and other heart muscle diseases known as cardiomyopathies.
Details
Part of-Myocardium of the heart
Identifiers-
Latin -Textus muscularis $ striatus cardiacus
TH- H2.00.05.2.02001, H2.00.05.2.00004
FMA- 14068
Striated muscle tissue is a muscle tissue that features repeating functional units called sarcomeres. The presence of sarcomeres manifests as a series of bands visible along the muscle fibers, which is responsible for the striated appearance observed in microscopic images of this tissue. There are two types of striated muscles:
Cardiac muscle (heart muscle)
Skeletal muscle (muscle attached to the skeleton)
Skeletal muscle includes skeletal muscle fibers, blood vessels, nerve fibers, and connective tissue. Skeletal muscle is wrapped in epimysium, allowing structural integrity of the muscle despite contractions. The perimysium organizes the muscle fibers, which are encased in collagen and endomysium, into fascicles. Each muscle fiber contains sarcolemma, sarcoplasm, and sarcoplasmic reticulum. The functional unit of a muscle fiber is called a sarcomere.[2] Each myofiber is composed of actin and myosin myofibrils repeated as a sarcomere.[3]
Based on their contractile and metabolic phenotypes, skeletal muscle can be classified as slow-oxidative (Type I) or fast-oxidative (Type II).[1]
Details
System-Musculoskeletal system
Identifiers
Latin-textus muscularis striatus
MeSH-D054792
TH-H2.00.05.2.00001
FMA-67905