112 Questions
What is the approximate diameter of cardiac muscle fibers?
15 µm
How are cardiac muscle fibers joined to each other?
Via intercalated discs
What type of myofilaments are attached to the intercalated discs in cardiac muscle fibers?
Thin myofilaments
How are cardiac muscle fibers arranged in relation to each other?
Parallel to each other
Which of the following is true about the arrangement of myofibrils in smooth muscle fibers?
The bundles of myofibrils are arranged parallel to each other, in a spiral fashion
What is the function of dense bodies in smooth muscle fibers?
Anchor thin myofilaments to the sarcolemma and transmit sliding of thick filaments
What is the difference in the actin/myosin coefficient between smooth muscle and skeletal muscle?
It is double in smooth muscle compared to skeletal muscle
What is the role of intermediate filaments desmin and vimentin in smooth muscle fibers?
Assist myofilaments in the process of contraction
What is the maximum percentage of length by which smooth muscle can shorten at rest?
10%
What is the function of caveolae in the sarcolemma of smooth muscle cells?
They have the same function as T tubules in skeletal and cardiac muscle
What is the arrangement of myofilaments in smooth muscle fibers?
Thin myofilaments contain actin, but not troponin, and are anchored in the sarcolemma by dense bodies
What is the role of the external lamina in smooth muscle fibers?
It surrounds the sarcolemma of the muscle cell
Which type of muscle tissue has transverse striations and one or two nuclei, with high energy consumption and abundant mitochondria?
Cardiac muscle
What characterizes the conductive fibers in the heart?
Include sinoatrial, atrioventricular, and His bundle cells
Which muscle tissue is characterized by slow and sustained involuntary contraction?
Smooth muscle
What is a characteristic of smooth muscle fibers?
Spindle-shaped with a central nucleus
Where does rhythmic contraction originate in the cardiac muscle?
Sinoatrial node
Which type of muscle cells are found in the digestive, reproductive, urinary, and respiratory systems, as well as in blood vessel walls, gland ducts, dermis, and ciliary bodies?
Smooth muscle cells
What regulates the heart rate for cardiac muscle fibers?
Autonomic nervous system
What type of muscle tissue can regenerate and originate from pericyte differentiation?
Smooth muscle
What is a characteristic of cardiac muscle cells?
Rhythmic contraction originating in the sinoatrial node
What characterizes the sarcolemma of cardiac muscle fibers?
Surrounded by a basal lamina and T tubules
What is a characteristic of smooth muscle fibers?
Lack transverse striations in longitudinal sections
What characterizes the size and content difference between atrial and ventricular contractile cardiac muscle fibers?
Differ in size and contain atrial natriuretic factor granules
Cardiac muscle fibers are joined to each other by desmosomes and gap junctions, which allow for the passage of ions and coordinated contraction.
True
Cardiac muscle fibers are surrounded by loose connective tissue that is rich in blood vessels.
True
The intercalated discs in cardiac muscle fibers have lateral portions that are rich in desmosomes and fasciae adherens.
False
The diameter of cardiac muscle fibers is approximately 15 µm.
False
Smooth muscle fibers can only shorten up to 10% of their length at rest.
True
The actin/myosin coefficient in smooth muscle is 4, due to each thick filament being surrounded by 15 thin filaments.
True
The sarcolemma of smooth muscle cells has numerous caveolae, which have the same function as the T tubules in skeletal and cardiac muscle.
True
The thick filaments in smooth muscle are thinner and less abundant compared to skeletal muscle.
False
The myofilaments in smooth muscle fibers are arranged in a spiral fashion.
True
The intermediate filaments desmin and vimentin play a role in the process of contraction in smooth muscle fibers.
True
Smooth muscle fibers can exert more force than skeletal muscle, given equal surface area.
True
The contraction of smooth muscle fibers follows the 'all or none law' as in skeletal muscle.
False
Cardiac muscle fibers lack transverse striations in longitudinal sections and have eosinophilic, homogeneous cytoplasm.
False
Smooth muscle fibers actively transport Ca++ from the extracellular fluid and contain abundant glycogen and lipid vesicles.
False
Conductive fibers in the heart include sinoatrial, atrioventricular, and His bundle cells, with Purkinje fibers for impulse conduction.
True
Smooth muscle can regenerate and originate from pericyte differentiation.
True
Cardiac muscle cells are found in the digestive, reproductive, urinary, and respiratory systems, as well as in blood vessel walls, gland ducts, dermis, and ciliary bodies.
False
The arrangement of myofilaments in cardiac muscle fibers is similar to smooth muscle, with rhythmic contraction originating in the sinoatrial node.
False
Cardiac muscle fibers are innervated by the autonomic nervous system, with sympathetic and parasympathetic regulation of heart rate.
True
Smooth muscle tissue is characterized by fast and sporadic voluntary contraction, found in various visceral and vascular systems.
False
Cardiac muscle fibers have transverse striations and one or two nuclei, with low energy consumption and scarce mitochondria.
False
Smooth muscle fibers are spindle-shaped with a central nucleus, have the ability to divide, and present Gap type junctions between adjacent cells.
True
Atrial and ventricular contractile cardiac muscle fibers differ in size and contain ventricular natriuretic factor granules.
False
The sarcolemma of smooth muscle fibers is surrounded by a basal lamina and T tubules, with underdeveloped sarcoplasmic reticulum cisterns forming diads.
False
What are the characteristic features of intercalated discs in cardiac muscle fibers?
Intercalated discs have transverse portions with numerous interdigitate papillary projections with adjacent fibers forming a complex union with desmosomes and fasciae adherens and lateral portions rich in gap junctions.
How are the cardiac muscle fibers arranged in relation to each other?
The cardiac muscle fibers are arranged parallel to each other forming fascicles or parallel sheets to the surface of the endocardium and epicardium and surrounded by loose connective tissue rich in blood vessels.
What is the approximate diameter of cardiac muscle fibers?
The approximate diameter of cardiac muscle fibers is about 15 µm.
What is the role of thin myofilaments in transmitting the movement of contraction in cardiac muscle fibers?
Thin myofilaments are attached to intercalated discs to transmit the movement of contraction from one cell to the adjacent one.
Explain the difference in myofilament arrangement between smooth muscle fibers and skeletal muscle fibers.
Smooth muscle fibers have myofibrils arranged parallel to each other in a spiral fashion, while skeletal muscle fibers have a more organized and specific sarcomere structure.
Describe the function and structure of dense bodies in smooth muscle fibers.
Dense bodies in smooth muscle fibers act as anchoring points for thin myofilaments and are electron dense structures that facilitate the sliding of filaments, wrinkling, and shortening of the cell during contraction.
Compare the actin/myosin coefficient in smooth muscle fibers with that in skeletal muscle fibers.
The actin/myosin coefficient in smooth muscle is 4, as each thick filament is surrounded by 15 thin filaments, while the coefficient in skeletal muscle is 6.
Explain the difference in the ability to shorten at rest between smooth muscle fibers and skeletal muscle fibers.
Smooth muscle fibers can only shorten up to 10% of their length at rest, while skeletal muscle fibers can shorten up to 30% of their length at rest.
Discuss the structural differences in the sarcolemma between smooth muscle fibers and skeletal muscle fibers.
The sarcolemma of smooth muscle fibers has numerous caveolae and pinocytic vesicles, as well as an external lamina and communicating junctions with adjacent cells, while the sarcolemma of skeletal muscle fibers is more focused on neuromuscular junctions and T tubules for excitation-contraction coupling.
Explain the role of intermediate filaments desmin and vimentin in the process of contraction in smooth muscle fibers.
Intermediate filaments desmin and vimentin help myofilaments in the process of contraction by providing structural support and aiding in the transmission of force during muscle contraction.
Describe the difference in the arrangement of myofibrils between smooth muscle fibers and cardiac muscle fibers.
Smooth muscle fibers have myofibrils arranged parallel to each other in a spiral fashion, while cardiac muscle fibers have a more organized and specific sarcomere structure similar to skeletal muscle fibers.
Explain the difference in the ability to follow the 'all or none law' between smooth muscle fibers and skeletal muscle fibers.
The contraction of smooth muscle fibers does not follow the 'all or none law' as in skeletal muscle, and only a part of the cell can contract, as well as contract gradually and progressively.
Explain the structure of the sarcolemma in cardiac muscle fibers and its surrounding components.
The sarcolemma in cardiac muscle fibers is surrounded by a basal lamina and T tubules, with underdeveloped sarcoplasmic reticulum cisterns forming diads.
What characterizes the difference between atrial and ventricular contractile cardiac muscle fibers?
Atrial and ventricular contractile cardiac muscle fibers differ in size and contain atrial natriuretic factor granules.
What are the different types of conductive fibers in the heart and their functions?
Conductive fibers in the heart include sinoatrial, atrioventricular, and His bundle cells, with Purkinje fibers for impulse conduction.
How are myofilaments arranged in cardiac muscle fibers, and where does rhythmic contraction originate?
The arrangement of myofilaments in cardiac muscle fibers is similar to skeletal muscle, with rhythmic contraction originating in the sinoatrial node.
What regulates the heart rate for cardiac muscle fibers?
Cardiac muscle fibers are innervated by the autonomic nervous system, with sympathetic and parasympathetic regulation of heart rate.
Describe the structure and characteristics of smooth muscle tissue.
Smooth muscle tissue is characterized by slow and sustained involuntary contraction, found in various visceral and vascular systems.
Where are smooth muscle cells found in the body, and what are their unique features?
Smooth muscle cells are found in the digestive, reproductive, urinary, and respiratory systems, as well as in blood vessel walls, gland ducts, dermis, and ciliary bodies. Smooth muscle fibers are spindle-shaped with a central nucleus, have the ability to divide, and present Gap type junctions between adjacent cells.
What is the regenerative capability of smooth muscle, and how does it originate?
Smooth muscle can regenerate and originate from pericyte differentiation.
What is the role of the autonomic nervous system in regulating cardiac muscle fibers?
The autonomic nervous system innervates cardiac muscle fibers, providing sympathetic and parasympathetic regulation of heart rate.
How does the structure of smooth muscle fibers differ from cardiac muscle fibers?
Smooth muscle fibers lack transverse striations in longitudinal sections and have eosinophilic, homogeneous cytoplasm.
What are the characteristics of conductive fibers in the heart, and what is their role in impulse conduction?
Conductive fibers in the heart, including sinoatrial, atrioventricular, and His bundle cells, along with Purkinje fibers, are responsible for impulse conduction.
______ muscle tissue is composed of muscle fibers of cylindrical morphology, about 15 µm in diameter and 85-100 µm in length. They are often bifurcated at their ends and are joined to each other by intercalated discs, visible with the light microscope, especially by iron hematoxylin stains. Intercalated discs have transverse portions with numerous interdigitate papillary projections with adjacent fibers forming a complex union with desmosomes and fasciae adherens and lateral portions rich in gap junctions. Thin myofilaments are attached to them to transmit the movement of contraction from one cell to the adjacent one. Between the adherens junctions of the intercalated discs there are numerous communicating junctions, which favour the passage of ions from one cell to the next, thus allowing the contraction to take place in a progressive and coordinated manner. The cardiac muscle fibers are arranged parallel to each other forming fascicles or parallel sheets to the surface of the endocardium and epicardium and surrounded by loose connective tissue rich in blood vessels.
Cardiac
Cardiac muscle fibers are arranged parallel to each other forming ______ or parallel sheets to the surface of the endocardium and epicardium and surrounded by loose connective tissue rich in blood vessels.
fascicles
Intercalated discs have transverse portions with numerous ______ papillary projections with adjacent fibers forming a complex union with desmosomes and fasciae adherens and lateral portions rich in gap junctions.
interdigitate
Thin myofilaments are attached to them to ______ the movement of contraction from one cell to the adjacent one.
transmit
Cardiac muscle fibers actively transport ______ from the extracellular fluid and contain abundant glycogen and lipid vesicles
Ca++
Conductive fibers in the heart include ______, atrioventricular, and His bundle cells, with Purkinje fibers for impulse conduction
sinoatrial
Smooth muscle tissue is characterized by slow and sustained ______ contraction, found in various visceral and vascular systems
involuntary
Smooth muscle cells are found in the digestive, reproductive, urinary, and respiratory systems, as well as in blood vessel walls, gland ducts, dermis, and ______ bodies
ciliary
The arrangement of myofilaments in cardiac muscle fibers is similar to skeletal muscle, with rhythmic contraction originating in the ______ node
sinoatrial
Cardiac muscle fibers are innervated by the autonomic nervous system, with sympathetic and ______ regulation of heart rate
parasympathetic
Smooth muscle can ______ and originate from pericyte differentiation
regenerate
Smooth muscle fibers lack transverse striations in ______ sections and have eosinophilic, homogeneous cytoplasm
longitudinal
Conductive fibers in the heart include sinoatrial, ______, and His bundle cells, with Purkinje fibers for impulse conduction
atrioventricular
Smooth muscle fibers are spindle-shaped with a central nucleus, have the ability to divide, and present Gap type junctions between adjacent ______
cells
Smooth muscle can regenerate and originate from ______ differentiation
pericyte
Cardiac muscle fibers have transverse striations and one or two nuclei, with high energy consumption and abundant ______
mitochondria
The thick filaments in smooth muscle are thicker than in skeletal muscle, but they are less abundant. Thus, the actin/myosin coefficient is the double that in skeletal muscle, 4 because each thick filament is surrounded by ______ thin filaments instead of 6 as in skeletal muscle.
15
The thin myofilaments contain actin, but not troponin, and in some types of smooth muscle neither ______.
tropomyosin
The thick filaments have heavy meromyosin throughout their length, so they can slide further over each other. This sliding is transmitted to dense bodies, wrinkling and shortening the cell, up to 10% of its length at rest, while skeletal muscle can only shorten up to 30% of its length at rest. Therefore, with equal surface area, smooth muscle can exert more force than ______ muscle.
skeletal
The sarcolemma or cytoplasmic membrane of these cells has numerous caveolae on both sides of the nuclei, which have the same function as the T tubules in skeletal and ______ muscle, as well as pinocytic vesicles. There is also an external lamina surrounding the sarcolemma, as well as numerous communicating junctions with adjacent cells. As organelles, mitochondria, rough endoplasmic reticulum, and a small Golgi complex are usually arranged on either side of the nucleus. Intermediate filaments (desmin and vimentin) are also present in the sarcoplasm and help myofilaments in the process of contraction. Myofibrils have a very different arrangement than skeletal and ______ muscle. The bundles of myofibrils are arranged parallel to each other, in a spiral fashion. The thin myofilaments contain actin, but not troponin, and in some types of smooth muscle neither tropomyosin. These filaments are very long, helical in arrangement, and are anchored in the sarcolemma by dense bodies, which act in a similar way to the Z line of skeletal muscle. Dense bodies can be revealed with the light microscope and iron hematoxylin stains, being very electron dense.
cardiac
The structure of smooth muscle fibers is something different from that of striated muscle fibers, since the myofilaments are not arranged forming specific structures. However, they show a complex structuring to favour muscle contraction. Figure 3. Smooth muscle structure (adapted from de Gartner y Hiat, 2013, Color Atlas and Text of Histology, 6th Ed.). The sarcolemma or cytoplasmic membrane of these cells has numerous caveolae on both sides of the nuclei, which have the same function as the T tubules in skeletal and cardiac muscle, as well as pinocytic vesicles. There is also an external lamina surrounding the sarcolemma, as well as numerous communicating junctions with adjacent cells. As organelles, mitochondria, rough endoplasmic reticulum, and a small Golgi complex are usually arranged on either side of the nucleus. Intermediate filaments (desmin and vimentin) are also present in the sarcoplasm and help myofilaments in the process of contraction. Myofibrils have a very different arrangement than skeletal and ______ muscle.
cardiac
The bundles of myofibrils are arranged parallel to each other, in a spiral fashion. The thin myofilaments contain actin, but not troponin, and in some types of smooth muscle neither tropomyosin. These filaments are very long, helical in arrangement, and are anchored in the sarcolemma by dense bodies, which act in a similar way to the Z line of skeletal muscle. Dense bodies can be revealed with the light microscope and iron hematoxylin stains, being very electron dense. The thick filaments are thicker than in skeletal muscle, but they are less abundant. Thus, the actin/myosin coefficient is the double that in skeletal muscle, 4 because each thick filament is surrounded by 15 thin filaments instead of 6 as in ______ muscle.
skeletal
There is also an external lamina surrounding the sarcolemma, as well as numerous communicating junctions with adjacent cells. As organelles, mitochondria, rough endoplasmic reticulum, and a small Golgi complex are usually arranged on either side of the nucleus. Intermediate filaments (desmin and vimentin) are also present in the sarcoplasm and help myofilaments in the process of contraction. Myofibrils have a very different arrangement than skeletal and cardiac muscle. The bundles of myofibrils are arranged parallel to each other, in a spiral fashion. The thin myofilaments contain actin, but not troponin, and in some types of ______ muscle neither tropomyosin. These filaments are very long, helical in arrangement, and are anchored in the sarcolemma by dense bodies, which act in a similar way to the Z line of skeletal muscle. Dense bodies can be revealed with the light microscope and iron hematoxylin stains, being very electron dense.
smooth
The contraction of smooth muscle fibers does not follow the ______ law as in skeletal muscle, but a part of the cell can contract, as well as contract gradually and progressively.
'all or none'
The sarcolemma or cytoplasmic membrane of these cells has numerous caveolae on both sides of the nuclei, which have the same function as the T tubules in skeletal and cardiac muscle, as well as pinocytic vesicles. There is also an external lamina surrounding the sarcolemma, as well as numerous communicating junctions with adjacent cells. As organelles, mitochondria, rough endoplasmic reticulum, and a small Golgi complex are usually arranged on either side of the nucleus. Intermediate filaments (desmin and vimentin) are also present in the sarcoplasm and help myofilaments in the process of contraction. Myofibrils have a very different arrangement than skeletal and cardiac muscle. The bundles of myofibrils are arranged parallel to each other, in a spiral fashion. The thin myofilaments contain actin, but not troponin, and in some types of smooth muscle neither tropomyosin. These filaments are very long, helical in arrangement, and are anchored in the sarcolemma by dense bodies, which act in a similar way to the Z line of skeletal muscle. Dense bodies can be revealed with the light microscope and iron hematoxylin stains, being very electron dense. The thick filaments are thicker than in skeletal muscle, but they are less abundant. Thus, the actin/myosin coefficient is the double that in skeletal muscle, 4 because each thick filament is surrounded by 15 thin filaments instead of 6 as in skeletal muscle.
gradually and progressively
Match the following characteristics with the correct muscle type:
Cardiac muscle fibers = Joined to each other by intercalated discs with transverse portions having numerous interdigitate papillary projections and lateral portions rich in gap junctions Smooth muscle fibers = Contain dense bodies that act in a similar way to the Z line of skeletal muscle
Match the organelle or structure with its location or function in smooth muscle fibers:
Caveolae = Located on both sides of the nuclei, function similar to T tubules in skeletal and cardiac muscle Dense bodies = Anchored in the sarcolemma, act similar to the Z line of skeletal muscle External lamina = Surrounds the sarcolemma Communicating junctions = Found with adjacent cells, favor the passage of ions
Match the myofilament characteristic with the type of muscle fiber:
Thin myofilaments contain actin, but not troponin = Smooth muscle fibers Thin myofilaments are attached to intercalated discs = Cardiac muscle fibers Thick filaments are less abundant and thicker than in skeletal muscle = Smooth muscle fibers Thick filaments have heavy meromyosin throughout their length = Smooth muscle fibers
Match the type of muscle fiber with its unique contraction characteristic:
Can exert more force than skeletal muscle with equal surface area = Smooth muscle fibers Can only shorten up to 30% of its length at rest = Skeletal muscle fibers Can contract gradually and progressively = Smooth muscle fibers Follows the 'all or none law' in contraction = Skeletal muscle fibers
Match the cell junction with its location or function in cardiac muscle fibers:
Desmosomes and fasciae adherens = Form a complex union with adjacent fibers Gap junctions = Rich in lateral portions, favor passage of ions Communicating junctions = Favor the passage of ions, allow progressive and coordinated contraction Intercalated discs = Visible with the light microscope, especially by iron hematoxylin stains
Match the following characteristics with the correct muscle type:
Cardiac muscle fibers = Have transverse striations and one or two nuclei Smooth muscle tissue = Characterized by slow and sustained involuntary contraction Conductive fibers in the heart = Include sinoatrial, atrioventricular, and His bundle cells, with Purkinje fibers for impulse conduction Autonomic nervous system regulation = Innervates cardiac muscle fibers, with sympathetic and parasympathetic regulation of heart rate
Match the following descriptions with the correct feature of smooth muscle fibers:
Spindle-shaped with a central nucleus = Smooth muscle fibers Ability to divide and present Gap type junctions between adjacent cells = Smooth muscle cells Found in various visceral and vascular systems = Smooth muscle tissue Lack transverse striations in longitudinal sections and have eosinophilic, homogeneous cytoplasm = Smooth muscle fibers
Match the following components with their role in cardiac muscle fibers:
Basal lamina and T tubules = Surround the sarcolemma and aid in impulse conduction Underdeveloped sarcoplasmic reticulum cisterns forming diads = Surround the sarcolemma and aid in impulse conduction Atrial and ventricular contractile cardiac muscle fibers = Differ in size and contain atrial natriuretic factor granules Arrangement of myofilaments in cardiac muscle fibers = Similar to skeletal muscle, with rhythmic contraction originating in the sinoatrial node
Match the following organelles with their location in smooth muscle fibers:
Mitochondria, rough endoplasmic reticulum, and a small Golgi complex = Arranged on either side of the nucleus Intermediate filaments (desmin and vimentin) = Present in the sarcoplasm and help myofilaments in the process of contraction Dense bodies = Anchored in the sarcolemma and act in a similar way to the Z line of skeletal muscle Pinocytic vesicles = Present in the cytoplasm and have a similar function as T tubules in skeletal and cardiac muscle
Match the following characteristics with the correct statement about smooth muscle contraction:
Follows the 'all or none law' = Skeletal muscle fibers Can shorten up to 10% of its length at rest = Smooth muscle fibers Does not follow the 'all or none law' = Smooth muscle fibers Can contract gradually and progressively = Smooth muscle fibers
Match the following descriptions with the correct feature of cardiac muscle fibers:
Actively transport Ca++ from the extracellular fluid = Cardiac muscle cells Contain abundant glycogen and lipid vesicles = Cardiac muscle cells Innervated by the autonomic nervous system = Cardiac muscle fibers Arranged parallel to each other forming fascicles or parallel sheets to the surface of the endocardium and epicardium = Cardiac muscle fibers
What is the function of caveolae in the sarcolemma of smooth muscle cells?
They are involved in the transmission of muscle contraction signals
What are the characteristics of conductive fibers in the heart, and what is their role in impulse conduction?
They are involved in transmitting electrical impulses and coordinating contraction
How are myofilaments arranged in cardiac muscle fibers, and where does rhythmic contraction originate?
The myofilaments are arranged in a parallel fashion, and rhythmic contraction originates in the sarcoplasmic reticulum
What is the role of intermediate filaments desmin and vimentin in smooth muscle fibers?
They help myofilaments in the process of contraction
What regulates the heart rate for cardiac muscle fibers?
The conductive fibers coordinating impulse conduction
Study Notes
Cardiac Muscle Structure and Function
- Cardiac muscle fibers have transverse striations and one or two nuclei, with high energy consumption and abundant mitochondria
- The sarcolemma is surrounded by a basal lamina and T tubules, with underdeveloped sarcoplasmic reticulum cisterns forming diads
- Cardiac muscle cells actively transport Ca++ from the extracellular fluid and contain abundant glycogen and lipid vesicles
- Atrial and ventricular contractile cardiac muscle fibers differ in size and contain atrial natriuretic factor granules
- Conductive fibers in the heart include sinoatrial, atrioventricular, and His bundle cells, with Purkinje fibers for impulse conduction
- The arrangement of myofilaments in cardiac muscle fibers is similar to skeletal muscle, with rhythmic contraction originating in the sinoatrial node
- Cardiac muscle fibers are innervated by the autonomic nervous system, with sympathetic and parasympathetic regulation of heart rate
- Smooth muscle tissue is characterized by slow and sustained involuntary contraction, found in various visceral and vascular systems
- Smooth muscle fibers are spindle-shaped with a central nucleus, have the ability to divide, and present Gap type junctions between adjacent cells
- Smooth muscle can regenerate and originate from pericyte differentiation
- Smooth muscle cells are found in the digestive, reproductive, urinary, and respiratory systems, as well as in blood vessel walls, gland ducts, dermis, and ciliary bodies
- Smooth muscle fibers lack transverse striations in longitudinal sections and have eosinophilic, homogeneous cytoplasm
Cardiac Muscle Structure and Function
- Cardiac muscle fibers have transverse striations and one or two nuclei, with high energy consumption and abundant mitochondria
- The sarcolemma is surrounded by a basal lamina and T tubules, with underdeveloped sarcoplasmic reticulum cisterns forming diads
- Cardiac muscle cells actively transport Ca++ from the extracellular fluid and contain abundant glycogen and lipid vesicles
- Atrial and ventricular contractile cardiac muscle fibers differ in size and contain atrial natriuretic factor granules
- Conductive fibers in the heart include sinoatrial, atrioventricular, and His bundle cells, with Purkinje fibers for impulse conduction
- The arrangement of myofilaments in cardiac muscle fibers is similar to skeletal muscle, with rhythmic contraction originating in the sinoatrial node
- Cardiac muscle fibers are innervated by the autonomic nervous system, with sympathetic and parasympathetic regulation of heart rate
- Smooth muscle tissue is characterized by slow and sustained involuntary contraction, found in various visceral and vascular systems
- Smooth muscle fibers are spindle-shaped with a central nucleus, have the ability to divide, and present Gap type junctions between adjacent cells
- Smooth muscle can regenerate and originate from pericyte differentiation
- Smooth muscle cells are found in the digestive, reproductive, urinary, and respiratory systems, as well as in blood vessel walls, gland ducts, dermis, and ciliary bodies
- Smooth muscle fibers lack transverse striations in longitudinal sections and have eosinophilic, homogeneous cytoplasm
Cardiac Muscle Structure and Function
- Cardiac muscle fibers have transverse striations and one or two nuclei, with high energy consumption and abundant mitochondria
- The sarcolemma is surrounded by a basal lamina and T tubules, with underdeveloped sarcoplasmic reticulum cisterns forming diads
- Cardiac muscle cells actively transport Ca++ from the extracellular fluid and contain abundant glycogen and lipid vesicles
- Atrial and ventricular contractile cardiac muscle fibers differ in size and contain atrial natriuretic factor granules
- Conductive fibers in the heart include sinoatrial, atrioventricular, and His bundle cells, with Purkinje fibers for impulse conduction
- The arrangement of myofilaments in cardiac muscle fibers is similar to skeletal muscle, with rhythmic contraction originating in the sinoatrial node
- Cardiac muscle fibers are innervated by the autonomic nervous system, with sympathetic and parasympathetic regulation of heart rate
- Smooth muscle tissue is characterized by slow and sustained involuntary contraction, found in various visceral and vascular systems
- Smooth muscle fibers are spindle-shaped with a central nucleus, have the ability to divide, and present Gap type junctions between adjacent cells
- Smooth muscle can regenerate and originate from pericyte differentiation
- Smooth muscle cells are found in the digestive, reproductive, urinary, and respiratory systems, as well as in blood vessel walls, gland ducts, dermis, and ciliary bodies
- Smooth muscle fibers lack transverse striations in longitudinal sections and have eosinophilic, homogeneous cytoplasm
Cardiac Muscle Structure and Function
- Cardiac muscle fibers have transverse striations and one or two nuclei, with high energy consumption and abundant mitochondria
- The sarcolemma is surrounded by a basal lamina and T tubules, with underdeveloped sarcoplasmic reticulum cisterns forming diads
- Cardiac muscle cells actively transport Ca++ from the extracellular fluid and contain abundant glycogen and lipid vesicles
- Atrial and ventricular contractile cardiac muscle fibers differ in size and contain atrial natriuretic factor granules
- Conductive fibers in the heart include sinoatrial, atrioventricular, and His bundle cells, with Purkinje fibers for impulse conduction
- The arrangement of myofilaments in cardiac muscle fibers is similar to skeletal muscle, with rhythmic contraction originating in the sinoatrial node
- Cardiac muscle fibers are innervated by the autonomic nervous system, with sympathetic and parasympathetic regulation of heart rate
- Smooth muscle tissue is characterized by slow and sustained involuntary contraction, found in various visceral and vascular systems
- Smooth muscle fibers are spindle-shaped with a central nucleus, have the ability to divide, and present Gap type junctions between adjacent cells
- Smooth muscle can regenerate and originate from pericyte differentiation
- Smooth muscle cells are found in the digestive, reproductive, urinary, and respiratory systems, as well as in blood vessel walls, gland ducts, dermis, and ciliary bodies
- Smooth muscle fibers lack transverse striations in longitudinal sections and have eosinophilic, homogeneous cytoplasm
Cardiac Muscle Structure and Function
- Cardiac muscle fibers have transverse striations and one or two nuclei, with high energy consumption and abundant mitochondria
- The sarcolemma is surrounded by a basal lamina and T tubules, with underdeveloped sarcoplasmic reticulum cisterns forming diads
- Cardiac muscle cells actively transport Ca++ from the extracellular fluid and contain abundant glycogen and lipid vesicles
- Atrial and ventricular contractile cardiac muscle fibers differ in size and contain atrial natriuretic factor granules
- Conductive fibers in the heart include sinoatrial, atrioventricular, and His bundle cells, with Purkinje fibers for impulse conduction
- The arrangement of myofilaments in cardiac muscle fibers is similar to skeletal muscle, with rhythmic contraction originating in the sinoatrial node
- Cardiac muscle fibers are innervated by the autonomic nervous system, with sympathetic and parasympathetic regulation of heart rate
- Smooth muscle tissue is characterized by slow and sustained involuntary contraction, found in various visceral and vascular systems
- Smooth muscle fibers are spindle-shaped with a central nucleus, have the ability to divide, and present Gap type junctions between adjacent cells
- Smooth muscle can regenerate and originate from pericyte differentiation
- Smooth muscle cells are found in the digestive, reproductive, urinary, and respiratory systems, as well as in blood vessel walls, gland ducts, dermis, and ciliary bodies
- Smooth muscle fibers lack transverse striations in longitudinal sections and have eosinophilic, homogeneous cytoplasm
Test your knowledge of cardiac and smooth muscle structure and function with this quiz. Explore the characteristics of cardiac muscle fibers, conductive fibers in the heart, and the innervation of cardiac muscle. Then, delve into the unique features of smooth muscle tissue, including its appearance, distribution, and regenerative abilities.
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