What organelles are found in cardiac muscle cells?
Under the microscope, cardiac muscle is seen to consist of interlacing bundles of cardiac myocytes (muscle cells). Like skeletal muscle it is striated with narrow dark and light bands, due to the parallel arrangement of actin and myosin filaments that extend from end to end of each myocyte. However, cardiac myocytes are narrower and much shorter than skeletal muscle cells, being about 0.02 mm wide and 0.1 mm long, and are more rectangular than smooth muscle cells, which are normally spindle-shaped. They are often branched, and contain one nucleus but many mitochondria, which provide the energy required for contraction. A prominent and unique feature of cardiac muscle is the presence of irregularly-spaced dark bands between myocytes. These are known as intercalated discs, and are due to areas where the membranes of adjacent myocytes come very close together. The intercalated discs have two important functions: one is to ‘glue’ the myocytes together so that they do not pull apart when the heart contracts; the other is to allow an electrical connection between the cells, which, as we will see, is vital to the function of the heart as a whole. The electrical connection is made via special junctions (gap junctions) between adjoining myocytes, containing pores through which small ions and therefore electrical current can pass. As the myocytes are electrically connected, cardiac muscle is often referred to as a functional syncytium (continuous cellular material).
What organelles are in a skeletal muscle cell?
The most prominent organelles in skeletal muscle are myofibrils - the contractile apparatus mostly containing the proteins actin and myosin with the regulatory proteins troponin and tropomyosin. The cell also has multiple nuclei scattered along the length of the cell so that diffusion of mRNA for new protein synthesis can occur without long distance diffusion. The endoplasmic reticulum is adapted for rapid calcium release and sequestration and called the sarcoplasmic reticulum. Mitochondria are prominent, with more in slow twitch fibers and will consist of more of the volume of the muscle cell when the cell is adapted to endurance training.
What are the functions of organelles?
Organelles are the living bodies inside the cells. These are mainly the characteristics of a eukaryotic cell. These show the division of labour at cellular level and carry out all the activities inside a cell. The physiology of a cell can be attributed to the collective functions of these organelles. Each organelle has it's specific function(s). The functions of major organelles can be stated briefly as - Nucleus - stores the genetic material ; controller and director of all cellular functionsEndoplasmic reticulum - structural frame to cell and skeleton of cell ; cell junction formation; secretion ; protein synthesis (rough ER) ; lipid and derivatives are synthesized(smooth ER)Golgi bodies - modification of synthesized materials (ex. proteins and lipids) ; regulation of molecular traffic inside the cell ; secretion (intracellular as well as outside)Mitochondria - site of aerobic respiration as well as synthesis of many useful substances Lysosomes - hydrolytic digestive enzymes active at acidic pH and help in digestion of unwanted,old,dead substanesRibosomes - site of protein synthesisPlastids - store reserve food materials and pigmentsCentrosome - involved in cell division Cilia and flagella - extend outside the cell and help in motility Vacuole - stores excess minerals , water and excretory substances which are transported inside against the concentration gradientCytoplasm - the main arena for all the cellular activites ; polyphasic and crysto - colloidal in natureCell wall - outermost covering ; mechanical support and protection ; permeable in nature ; variable composition among different groups of organismsCell membrane - selectively permeable ; composed of mainly lipids and proteins ; universal layer ; inner to cell membraneBesides these, the microtubules and microfilaments are also present which provide support to the cell and may be involved in motility.
How does muscle tissue structure relate to its function?
The structure of muscle tissue varies depending upon whether the muscle controls voluntary or involuntary movements, according to the National Cancer Institute. There are three types of muscle: skeletal, smooth and cardiac. Skeletal muscle is striated, smooth muscle is non-striated and cardiac muscle has characteristics of both.Skeletal muscle is the muscle that attaches to the bones. These muscles control voluntary movements, or movement under conscious control. These muscle cells are arranged in bundles of nerve fibers. They produce short, intense contractions.Smooth muscle controls involuntary movements in the internal organs. The individual cells are organized with a single central nucleus rather than in bundles of fibers. Smooth muscle contracts slowly and in a steady rhythm.Cardiac muscle is the muscle that makes up the heart. It contracts involuntarily, but its cellular structure is organized in bundles like skeletal muscle. However, the bundles in cardiac muscle are arranged differently. Cardiac muscle creates strong, rhythmic contractions.
Which organelle is known as an 'organelle within an organelle'?
A mitochondrion which is an organelle contains ribosomes which are also organelles(well thats what we're taught in school) but it is argued whether ribosomes are organelles or not :)
What is the role of organelles in skeletal muscle cells?
Organelles of a skeletal muscle cell contain the same organelles as other animal cells, with the addition of myofibrils. Muscle fibers within the skeletal cell are known as myofibers. These organelles allow skeletal muscle cells to contract. Skeletal muscle cells do contain more mitochondria than other cells, because muscle cells require more energy and must convert more glucose. Skeletal muscle cells also differ from other cells because of the myofilaments within the myofibrils. Within these filaments are proteins known as myosin and actin. The special filaments enable the skeletal muscles to contract. The myofibrils within skeletal muscle cells are divided into units known as sarcomeres, which are the units of skeletal muscle cell contraction.
What are the parts of an animal cell and its functions?
Animal cells are eukaryotic cells which are surrounded by plasma membrane. It contains the nucleus and organelles that are membrane bound. The cell organelles have a vast range of functions to perform like hormone and enzyme production to providing energy for the cells. Animal cells lack cell wall, a large vacuole and plastids. Due to the lack of the cell wall, the shape and size of the animal cells are mostly irregular. Most of the cells size range between 1 and 100 micrometers and are visible only with help of microscope. Trillions of cells are found in the human body. There are many different types of cells, approximately 210 distinct cell types in adult human body.Fig. Structure of Animal CellComponents of an animal cell are as follows:Cell membrane - forms the outer covering of the cell made up of phospholipids which has polar (hydrophillic) heads and non-polar (hydrophobic) tails and is semi-permeable.Cytoplasm - is a gel-like matrix where all the other cell organelles are suspended inside the cell and ensures the cell doesn't shrink or burst.Nucleus - contains the hereditary material DNA and directs the activities of the cell.Centrioles - organize the microtubules assembly during cell division.Endoplasmic Reticulum - are a network of membranes composed of rough and smooth endoplasmic reticulum.Golgi complex - is responsible for storing, packaging of cellular products.Lysosomes - are enzyme sacs that digest cellular wastes.Microtubules - are hollow rods, function primarily as support and shape to the cell.Mitochondria - is the site for cellular respiration and producers of energy.Ribosomes - are made of RNA and proteins, and are sites for protein synthesis.Nucleolus - is the structure within the nucleus and helps in synthesis of ribosomes.Nucleopore - is the tiny hole in the nuclear membrane, allows the movement of nucleic acids and proteins in/out of the cell.
What are the types of cell and tissues?
it might be placed into one of two groups: the prokaryotes and the eukaryotes. A prokaryote is an organism that is almost always single-celled (except for prokaryote colonies), always reproduces by means of binary fission and does not have a cell nucleus or any other organelles contained within a membrane. The prokaryote’s DNA travels openly around the cell and...................................... Epithelial tissue covers the body surface and forms the lining for most internal cavities. The major function of epithelial tissue includes protection, secretion, absorption, and filtration. The skin is an organ made up of epithelial tissue which protects the body from dirt, dust, bacteria and other microbes that may be harmful. Cells of the epithelial tissue have different shapes as shown on the student's worksheet. Cells can be thin, flat to cubic to elongated. Connective tissue is the most abundant and the most widely distributed of the tissues. Connective tissues perform a variety of functions including support and protection. The following tissues are found in the human body, ordinary loose connective tissue, fat tissue, dense fibrous tissue, cartilage, bone, blood, and lymph, which are all considered connective tissue. There are three types of muscle tissue: skeletal, smooth, and cardiac. Skeletal muscle is a voluntary type of muscle tissue that is used in the contraction of skeletal parts. Smooth muscle is found in the walls of internal organs and blood vessels. It is an involuntary type. The cardiac muscle is found only in the walls of the heart and is involuntary in nature. Nerve tissue is composed of specialized cells which not only receive stimuli but also conduct impulses to and from all parts of the body. Nerve cells or neurons are long and string-like. In tissues the simplest combination is called a membrane, or a sheet of tissues which cover or line the body surface or divide organs into parts. Examples include the mucous membrane which lines body cavities. Tissues combine to form organs. An organ is a part of the body which performs a definite function. The final units of organization in the body are called systems. A system is a group of organs each of which contributes its share to the function of the body as a whole.