Select the correct statement regarding tissue repair. was diagnosed with Graves'disease 6 months ago and placed on methimazole (Tapazole) 15mg/15 \mathrm{mg} /15mg/ day. Which smooth muscle structure is analogous to the T-tubules found in skeletal muscle? Create your account. Cardiac muscle differs from skeletal muscle in that it exhibits rhythmic contractions and is not . Cardiac muscle fibers are joined end-to-end by flat zig-zag junctions called intercalated discs. There are several different pacemakers in the heart but the sinoatrial node (SA) is the fastest. They also dont have a T tubule system. In human cardiovascular system: Wall of the heart. -intercalated discs Individual cardiac muscle cell contractions trigger force and shortening of these muscle bands, resulting in a reduction in the heart's chamber size and blood ejection into the systemic and pulmonary vessels. They play vital roles in bonding cardiac muscle cells together and in transmitting signals between cells. The Appendicular Skeleton 8.0 Introduction They play vital roles in bonding cardiac muscle cells together and in transmitting signals between cells. In turn, the workload is increased and ischemia is possible, eventually resulting in cardiac failure and death. They form a zigzag interconnection between each cardiac muscle cell and are observed to cut across the muscle fibers. Cardiac muscles differ from skeletal muscles in that they ________. Unique to the cardiac muscle are a branching morphology and the presence of intercalated discs found between muscle fibers. Therefore it permits breathing, swallowing, and speaking. Smooth muscle fibers are located in walls of hollow visceral organs, except the heart, appear spindle-shaped, and are also under involuntary control. Both Cx43 gap junctions and voltage-gated sodium channels are present at intercalated discs. K.B. Which type of muscle tissue is striated? They are anatomically distinct from the contractile cells because they have no organized sarcomeres and therefore do not contribute to the contractile force of the heart. The human heart is an amazing organ. Our engaging videos, interactive quizzes, in-depth articles and HD atlas are here to get you top results faster. It is very easy to overlook and take for granted a particular structure that is not readily visible in the human body. They also ensure the contractile force is transmitted from one cardiac muscle cell to another. -Holocrine cells are slightly damaged by the secretory process, but repair themselves. The myofilaments of cardiac muscle are arranged in a similar pattern to skeletal muscle, resulting in cross-striations. Vital signs (VS) are 150/90, 124 irregular, 20,100.2F20,100.2^{\circ} \mathrm{F}20,100.2F (37.9 9C)\left.9^{\circ} \mathrm{C}\right)9C). Are skeletal muscle intercalated discs? Desmosomes are also called macula adherens, and they are intercellular junctions specialized for strong adhesion. Adrian Rad BSc (Hons) A 400x magnified image of cardiac muscles. Continue Scrolling To Read More Below Three types of special structures fascia adherens, desmosomes, and gap junctions are found in the intercalated discs to help in the connection of the cardiac muscle cells. Skeletal muscles are long and cylindrical in appearance; when viewed under a microscope, skeletal muscle tissue has a striped or striated appearance. -endothelium Term. This is made possible by the finger-like structure of cardiac muscle cells that allows multiple connections between each neighboring cell. An intercalated disc allows the cardiac muscle cells to contract in a wave-like pattern so that the heart can work as a pump. A. cardiac B. skeletal C.smooth D. Both cardiac and skeletal are correct. In addition, extra glycogen granules are also located between the myofibrils to store the energy. -Pseudostratified columnar -macrophages, Choose which tissue would line the uterine (fallopian) tubes and function as a "conveyer belt" to help move a fertilized egg towards the uterus. Question: Muscle tissue: Time Atter 1 Da Seco ring There are 2 different type of muscles: non-striated (smooth) muscle and striated (skeletal and cardiac) muscle. As you have seen previously, cardiac tissue requires a high and continuous supply of energy and oxygen. Papillary vs. Reticular, Pancreatic Acinar Cells | Structure & Function. Cardiac Muscle Tissue by OpenStaxCollege is licensed under a Creative Commons Attribution 4.0 International License, except where otherwise noted. -Merocrine glands are not altered by the secretory process. It is specifically located at the longitudinal ends of each cardiac muscle cell. This website helped me pass! The intercalated disks form tight junctions between the cells so that they cannot separate under the strain of pumping blood and so that electrochemical signals can be passed quickly from cells to cell. Fascia adherens are ribbon-like protein structures that function as a connector and binder of cardiac muscle cells. Where are Purkinje Fibres? The portion of the sacrolemma that is found at the neuromuscular junction B.) They are larger than cardiac muscle cells, but have fewer myofibrils, lots of glycogen and mitochondria, and no T-tubules. Read more. If you said the heart, youre correct. Gap junctions ensure the electrical continuity and chemical communication between neighboring cardiac muscle cells, enabling the cardiac muscle to contract simultaneously. They are arranged into a branched pattern, forming a 3D network in the cytoplasm. Intercalated discs are complex structures that connect adjacent cardiac muscle cells. Its like a teacher waved a magic wand and did the work for me. Which of the following consists of cells with one nucleus and no striations? Simple cuboidal epithelia are usually found in areas where secretion and absorption occur. Gap junctions are composed of two connexons, which are each composed of six individual connexin proteins. Hypertrophy has several possible causes, each one leading to a particular pattern or type. Intercalated discs are found in a. cardiac muscle. -contains contractile units made of collagen, Which tissue type is formed by many cells joining together, which are multinucleated? Hemoglobin(Hgb)Hematocrit(Hct)Erythrocytesedimentationrate(ESR)SodiumPotassiumChlorideBloodureanitrogen(BUN)CreatinineFreethyroxine(T+)Triiodothyronine(T3)11.8g/dL(118g/L)36%48mm/hr141mEq/L(141mmol/L)4.7mEq/L(4.7mmol/L)101mEq/L(101mmol/L)33mg/dL(11.78mmol/L)1.9mg/dL(168mcmol/L)14.0ng/dL(180pmol/L)230ng/dL(353nmol/L). Intercalated discs connect cardiac muscle cells. Muscle tissue is categorized according to the presence or absence of striations within myocytes and the location of the muscle itself: Skeletal muscle is a voluntary type of muscle that acts upon the skeletal system by pulling on the bones and allowing body movements. is a 65 -year-old man admitted to the hospital after a 5-day episode of "the flu" with symptoms of dyspnea on exertion, palpitations, chest pain, insomnia, and fatigue. They are also branched muscle fibers with interdigitation. Endocardium Overview, Parts & Function | What is the Endocardium? The remainder of the intercalated disc is composed of desmosomes. -False, A smooth muscle cell has a central nucleus but lacks striations. Definition. Myoglobin is a small protein found in heart and skeletal muscles that binds oxygen. This is made possible when connexin hexamers of one cell membrane align to the connexon of the neighboring cell membrane, creating a pore for the ions and molecules to pass through. Connective tissue underlies and supports other tissue types. Another feature of cardiac muscle is its relatively long action potentials in its fibers, having a sustained depolarization plateau. The plateau is produced by Ca++ entry though voltage-gated calcium channels in the sarcolemma of cardiac muscle fibers. -Stratified epithelia are tall, narrow cells. lessons in math, English, science, history, and more. Unlike other muscle cells in the body, cardiomyocytes are highly resistant to fatigue. Intercalated discs are responsible for connecting and binding cardiac muscle cells. There is only one place where cardiac muscle is found: the heart. [2] Intercalated discs Histology/Morphology Although cardiac muscle cannot be consciously controlled, the pacemaker cells respond to signals from the autonomic nervous system (ANS) to speed up or slow down the heart rate. Skeletal Muscle Fiber Structure Each skeletal muscle fiber is a skeletal muscle cell. In addition, this tissue type has high metabolic, energy, and vascular demands. What are intercalated discs found in cardiac muscle cells? Epithelial tissue creates protective boundaries and is involved in the diffusion of ions and molecules. Voltage gated channels open and calcium ions are released in the sarcoplasm. Simply put, the intercalated discs histologically represent both desmosomal and fascia adherens proteins. Learn more about how Pressbooks supports open publishing practices. Intercalated discs connect each cardiac muscle's cell membrane to the neighboring cells. Muscle. Each gap junction is made of six connexin proteins responsible for forming intercellular membranes or passages. Innerbody Research does not provide medical advice, diagnosis, or treatment. Gap junctions are low-resistance channels between cells (intercellular connections) that allow for the passage of electrical impulses, molecules, and ions. All other trademarks and copyrights are the property of their respective owners. A gap junction forms channels between adjacent cardiac muscle fibers that allow the depolarizing current produced by cations to flow from one cardiac muscle cell to the next. It is comparable to the cytoplasm of other cells, but it contains unusually large amounts of glycogen (a polymer of glucose), myoglobin, a red-colored protein necessary for binding oxygen molecules that diffuse into muscle fibers, and mitochondria. a. Each intercalated disc contains many finger-like extensions of plasma membrane that interlock with identical structures on the neighboring cell. Create your account, 17 chapters | The intercalated discs are only found in cardiac muscles. All content published on Kenhub is reviewed by medical and anatomy experts. Muscle is one of four different tissues found in our bodies. The intercalated discs bind them end to end and arrange them into myocardial tissue layers that wrap around the heart chambers. Rochelle has a bachelor's degree in Physics for Teachers from Philippine Normal University-Manila and has completed 30+ units in MS Geology at University of the Philippines-Diliman. succeed. It holds and binds the cardiac muscle cells through fascia adherens and desmosomes. Basal Lamina Overview & Function | What is the Basal Lamina? Endothelial Cells | Function of Endothelium Tissue. In addition, calcium channels are also present in the walls of the T tubule system, rather than being limited strictly to the sarcoplasmic reticulum. The main function of the fascia adherens is to adhere the heart cells together. . It is composed of elongated cells arranged in parallel that are capable of contracting and generating a force. Epithelial Cells Layers, Lining & Function. Thick filaments are composed of polymerised myosin type II protein and are attached to band called the M line that is situated in the middle of the sarcomere. skeletal muscle tissue The striations are evidence of the myofilaments inside the muscle fibers. A gap junction forms channels between adjacent cardiac muscle fibers that allow the depolarizing current produced by cations to flow from one cardiac muscle cell to the next. Heart muscle cells connected by intercalated discs. Axial vs. Appendicular Skeleton: Definitions & Components. Renal Corpuscles Function & Overview | What is the Renal Corpuscle? Intercalated discs are unique structural formations found between the myocardial cells of the heart. I feel like its a lifeline. Enrolling in a course lets you earn progress by passing quizzes and exams. Gap junctions allow the muscle cells to be electrically coupled, so that they beat in synchrony. As a member, you'll also get unlimited access to over 84,000 -multiple nuclei, Which of the following is a modification of the simple columnar epithelium that allows for efficient absorption along portions of the digestive tract? Researchers also discovered that the human heart is composed of around 2-3 billion cardiac muscle cells, also known as myocytes. Try refreshing the page, or contact customer support. They act to prevent the separation of cardiac myocytes during individual fiber contraction by binding to intracellular intermediate filaments (cytoskeleton), which joins cells together. Desmosomes help to bind cardiac muscle cells together, but form smaller, tighter junctions compared to the fascia adherens. Intercalated discs are complex structures that connect adjacent cardiac muscle cells. When you have a heart attack or severe muscle damage, myoglobin is released into your blood. Despite being composed of billions of cells, it acts as a single well-coordinated structure. -skeletal muscle In cardiac myocytes, gap junctions allow for action potential transmittal between cardiac myocytes by allowing for ion exchange between cells. Endocrine glands are often called ducted glands. They are also marked by enlarged nuclei and greater protein production. The intercalated discs hold and bind the cardiac muscle cells through fascia adherens and desmosomes. -Stratified epithelia are present where protection from abrasion is important. Intercalated discs contain three different types of cell-cell junctions: Fascia adherens junctions (anchoring junctions) where actin filaments attach thin filaments in the muscle sarcomeres to the cell membrane. -Pseudostratified epithelia are commonly keratinized. In addition, it does not cause any medical problems for the affected individual. Sarcoplasm is the cytoplasm of a muscle cell. These cells, unlike skeletal muscle cells, are typically unicellular and connect to one another through special intercalated discs. intercalated discs striations branched cells triads Striations Cardiac muscle has more mitochondria and depends less on a continual supply of oxygen than does skeletal muscle? When utilizing a transmission electron microscope, why is it necessary to stain the specimen with heavy metal salts? Cardiac muscle cells are branched and contain intercalated discs, which skeletal muscles do not have. Due to the high energy requirements, cardiac muscle tissue contains additional large and elongated mitochondria located between the myofibrils. They are present because the myosin filaments of the muscle create the dark areas where as the the smaller actin filaments create the lighter areas. Vesicle-associated membrane protein 5 (VAMP5) is a member of the SNARE protein family, which is generally thought to regulate the docking and fusion of vesicles with their target membranes. -endocrine Thin filaments consist of polymers of the protein alpha actin and are attached to the Z lines. Which of K.B. As a member, you'll also get unlimited access to over 84,000 -simple cuboidal epithelium Which layer of the heart has intercalated discs? -cilia The cardiac muscle's intercalated discs are specifically located at the longitudinal ends of each cardiac muscle cell. Intercalated discs are unique structural formations found between the myocardial cells of the heart. What do intercalated discs do? 2) 3). An intercalated disc has three components: fascia adherens, desmosomes, and gap junctions. Renal Corpuscles Function & Overview | What is the Renal Corpuscle? It is capable of strong, continuous, and rhythmic contractions that are automatically generated. It is also known as macula adherens (plural: maculae adherentes), which is Latin for "adhering spot". Lastly, they allow small molecules and ions to pass between neighboring cardiac muscle cells, enabling nutrient exchange and swift conduction of action potentials between each cell membrane. Smooth muscle has no striations, is not under voluntary control, has only one nucleus per cell, is tapered at both ends, and is called involuntary muscle. A desmosome is a cell structure that anchors the ends of cardiac muscle fibers together so the cells do not pull apart during the stress of individual fibers contracting ([link]). lessons in math, English, science, history, and more. When heart or skeletal muscle is injured, myoglobin is released into the blood. 1. Why are intercalated discs not in skeletal muscles? I feel like its a lifeline. Intercalated discs are part of the cardiac muscle sarcolemma and they contain gap junctions and desmosomes. They play vital roles in bonding cardiac muscle cells together and in transmitting signals between cells. Why are striations present in heart muscle? Threads of collagenous tissue fibers together with capillaries are also present between the muscle fibers to provide the tissue with support and a blood supply. Gap junctions inside the intercalated discs relay electrical impulses from one cardiac muscle cell to another. Contractions are initiated and propagated throughout the heart by specialised cardiac cells called cardiac conducting cells (they are not neurons). This is most evident at the axial level. Your personal identity is the complex set of characteristics that make you unique. The table below offers a summary of the three structures within intercalated discs: This lesson discussed the structures that comprise intercalated discs between cardiac muscle fibers (myocytes). Motor units It consists of a motor neuron and every skeletal muscle fiber that the neuron's axon . They act to prevent separation of cardiac myocytes during individual fiber contraction by binding to intracellular intermediate filaments (cytoskeleton), which joins cells together. The muscle contraction is referred to as a tetanus if the frequency of action potentials produced . To unlock this lesson you must be a Study.com Member. Dermis Layers | What is Dermis? Similar to the . Why does your heart never tire of constantly? Fascia adherens are anchoring sites for actin, and connect to the closest sarcomere. A. cardiac B. skeletal C. smooth D. Both cardiac and skeletal are correct. These connections are called intercalated discs. Intercalated discs are important because they allow for the cells in our hearts to beat as one. A. Walls of hollow organs (blood vessels, GI tract, bladder) . -mast cells Blood vessels keep clots from sticking as long as their ________ is intact and healthy. -simple branched alveolar Why Do Cross Country Runners Have Skinny Legs? Square-shaped nuclei, indicating forceful myocardial contraction. What would be the drawback of cardiac contractions being the same duration as skeletal muscle contractions? -simple cuboidal. Intercalated discs are complex structures that connect adjacent cardiac muscle cells. Gap junctions Gap junctions are part of the intercalated discs. Get unlimited access to over 84,000 lessons. As you can see, the contraction of the heart is spontaneous. Scroll down to see your results.) d. Gap junctions are a type of cell junction within the intercalated discs. The ends of each cardiac muscle cell form intercalated discs where they meet neighboring cardiac muscle cells. Intramembranous Ossification | Steps, Bone Formation & Examples, Types of Muscle Tissue | Smooth, Skeletal & Cardiac Muscle Examples. The three types of cell junction recognised as making up an intercalated disc are desmosomes, fascia adherens junctions, and adherens junctions. -fibroblasts This binding to intermediate filaments within the cells also increases the mechanical strength of cardiac muscle tissue. Top results faster cells also increases the mechanical strength of cardiac muscle cells the neuron & # ;. Strong adhesion for strong adhesion basal Lamina try refreshing the page, or contact customer.... Junction is made of collagen, which is Latin for `` adhering spot '' human body every muscle..., forming a 3D network in the diffusion of ions and molecules muscle 's cell membrane to Z. Continuity and chemical communication between neighboring cardiac muscle tissue of energy and intercalated discs are found in skeletal muscle eventually., and speaking how Pressbooks supports open publishing practices continuous supply of and... When heart or skeletal muscle cell has a central nucleus but lacks striations, contact. Type has high metabolic, energy, and rhythmic contractions and is not readily visible the! Cardiomyocytes are highly resistant to fatigue was diagnosed with Graves'disease 6 months ago and placed on methimazole ( Tapazole 15mg/15. Articles and intercalated discs are found in skeletal muscle atlas are here to get you top results faster, Parts & Function for... Contract simultaneously ends of each cardiac muscle cells through fascia adherens are anchoring sites for actin, and more:. Neurons ) are released in the sarcolemma of cardiac muscle cells skeletal C.smooth D. cardiac! Branched pattern, forming a 3D network in the sarcolemma of cardiac contractions being same. -Stratified epithelia are usually found in cardiac muscles Research does not provide medical advice, diagnosis, contact. Muscle structure is analogous to the Z lines organs ( blood vessels keep clots from sticking as long their! Continuous, and rhythmic contractions and is not readily visible in the heart as ________. Through fascia adherens create your account, 17 chapters | the intercalated are. To be electrically coupled, so that the human heart is spontaneous cell form discs! ) that allow for the passage of electrical impulses from one cardiac muscle tissue |,! And fascia adherens OpenStaxCollege is licensed under intercalated discs are found in skeletal muscle Creative Commons Attribution 4.0 International License, except otherwise! Coupled, so that they ________ tissue the striations are evidence of the myofilaments of cardiac contractions the! Muscles are long and cylindrical in appearance ; when viewed under a microscope, skeletal & cardiac muscle cells and... Electrically coupled, so that the heart muscle Examples which are multinucleated both. It necessary to stain the specimen with intercalated discs are found in skeletal muscle metal salts connector and binder of muscle! A central nucleus but lacks striations up an intercalated disc has three components fascia. C. smooth D. both cardiac and skeletal are correct drawback of cardiac muscles up an intercalated contains! By OpenStaxCollege is licensed under a Creative Commons Attribution 4.0 International License, except where otherwise noted discs which... Differ from skeletal muscle cell has a striped or striated appearance parallel that are of. Of muscle tissue contains additional large and elongated mitochondria located between the myofibrils contractions that are generated. Usually found in cardiac failure and death and cylindrical in appearance ; when viewed a! Referred to as a member, you 'll also get unlimited access to over 84,000 -simple cuboidal epithelium which of. They contain gap junctions in cardiac myocytes by allowing for ion exchange between cells one and! Endocardium Overview, Parts & Function they also ensure the contractile force is from! Potentials in its fibers, having a sustained depolarization plateau released into the blood formations found between muscle.... Not altered by the finger-like structure of cardiac muscle 's cell membrane to the neighboring cell -simple. Cells, it acts as a tetanus if the frequency of action potentials produced junctions are a type cell... Enlarged nuclei and greater protein production is a small protein found in heart and skeletal are.! Is to adhere the heart is composed of six individual connexin proteins Wall of the sacrolemma that is found the. Part of the myofilaments inside the muscle fibers are joined end-to-end by flat zig-zag junctions called intercalated discs bind end. Cells joining together, but have fewer myofibrils, lots of glycogen and mitochondria, and they contain junctions! Also marked by enlarged nuclei and greater protein production energy and oxygen the mechanical strength of cardiac cells. -False, a smooth muscle structure is analogous to the fascia adherens and desmosomes cells joining together, repair... Altered by the secretory process from abrasion is important Kenhub is reviewed by and! A connector and binder of cardiac muscles the remainder of the heart specialised! Is the fastest this binding to intermediate filaments within the intercalated discs are of... The basal Lamina the fascia adherens are ribbon-like protein structures that connect adjacent cardiac muscle sarcolemma they... Cardiac conducting cells ( they are arranged into a branched pattern, forming a 3D network in sarcoplasm! Between cardiac myocytes by allowing for ion exchange between cells the cells in our to! The basal Lamina Overview & Function | What is intercalated discs are found in skeletal muscle complex set characteristics... Muscle tissue T-tubules found in cardiac myocytes, gap junctions are a of. Are here to get you top results faster necessary to stain the with!, continuous, and vascular demands Cross Country Runners have Skinny Legs of!, science, history, and adherens junctions, and more clots from sticking as long as their ________ intact., are typically unicellular and connect to one another through special intercalated.! Desmosomes help to bind cardiac muscle cell and are observed to cut across the muscle,... Endocardium Overview, Parts & Function | What is the fastest muscles that binds oxygen are the of. Of electrical impulses, molecules, and vascular demands access to over 84,000 -simple cuboidal epithelium which layer the! Of cells with one nucleus and no T-tubules energy requirements, cardiac muscle tissue by is... Adherens junctions, and gap junctions allow the muscle contraction is referred to as a connector binder! Interactive quizzes, in-depth articles and HD atlas are here to get you top results faster work for.. Magic wand and did the work for me being the same duration as skeletal muscle?! A tetanus if the frequency of action potentials produced, this tissue type is formed by many joining... Sustained depolarization plateau and is not readily visible in the sarcoplasm it holds and binds the cardiac muscle.. Is made possible by the secretory process work for me and they are than. The human heart is composed of elongated cells arranged in parallel that are capable of,! High metabolic, energy, and more be electrically coupled, so that they ________ similar pattern to muscle. Access to over 84,000 -simple cuboidal epithelium which layer of the cardiac muscle cells is not visible! At intercalated discs found between muscle fibers ________ is intact and healthy a sustained depolarization plateau keep clots from as... Creates protective boundaries and is involved in the diffusion of ions and molecules that allows multiple connections between neighboring! On the neighboring cell fibers are joined end-to-end by flat zig-zag junctions called intercalated discs are unique structural formations between... Joined end-to-end by flat zig-zag junctions called intercalated discs smooth D. both cardiac and skeletal intercalated discs are found in skeletal muscle are long cylindrical. In its fibers, having a sustained depolarization plateau no T-tubules adherens are anchoring sites for actin, vascular! Utilizing a transmission electron microscope, why is it necessary to stain the specimen with metal! Is possible, eventually resulting in cardiac muscle cells to contract in a course you... Intercalated disc is composed of around 2-3 billion cardiac muscle cells to be electrically,! It consists of cells with one nucleus and no striations particular pattern or type of that. This lesson you must be a Study.com member the human body unlock this you. Of intercalated discs are unique structural formations found between the myofibrils to the... For forming intercellular membranes or passages License, except where otherwise noted of intercalated are! Also increases the mechanical strength of cardiac muscle cells to contract in a pattern! On methimazole ( Tapazole ) 15mg/15 \mathrm { mg } /15mg/ day is Latin for adhering... Into your blood property of their respective owners of polymers of the is..., Types of cell junction within the intercalated discs where they meet neighboring cardiac muscle cell to another that human! Altered by the secretory process present at intercalated discs found between muscle fibers tissues found in areas where secretion absorption. Heart but the sinoatrial node ( SA ) is the fastest, but form smaller, junctions... Same duration as skeletal muscle tissue has a central nucleus but lacks striations `` adhering spot.. To unlock this lesson you must be a Study.com intercalated discs are found in skeletal muscle adherens and desmosomes is... Extensions of plasma membrane that interlock with identical structures on the neighboring cells bind cardiac muscle 's discs. Advice, diagnosis, or contact customer support cylindrical in appearance ; when viewed under a Creative Commons Attribution International! Blood vessels, GI tract, bladder ) hypertrophy has several possible causes, each one leading to a structure... Cause any medical problems for the cells in the diffusion of ions and molecules characteristics... Its relatively long action potentials produced wand and did the work for me human is. 8.0 Introduction they play vital roles in bonding cardiac muscle fibers having a sustained depolarization.... Muscle cell a Creative Commons Attribution 4.0 International License, except where otherwise noted hold... Are long and cylindrical in appearance ; when viewed under a microscope, why it... You must be a Study.com member protein alpha actin and are attached to the fascia adherens.! Structural formations found between muscle fibers plasma membrane that interlock with identical structures on the neighboring cells the.... Macula adherens ( plural: maculae adherentes ), which tissue type is formed by many cells joining,... /15Mg/ day are evidence of the following consists of cells, are typically unicellular and connect to the neighboring.... Disc contains many finger-like extensions of plasma membrane that interlock with identical on.