Functionally cardiac muscles are similar to :-
Cardiac muscles are the heart muscles. Many cardiac muscle cells assemble in a branching pattern to form a cardiac muscle. Based on appearance, cardiac muscles are striated muscles or unstriped muscles. They are also involuntary in nature as smooth muscles.
Thus, the correct answer is option A.
Covering of muscle :-
Fascia (or "deep fascia") is a layer of thickened connective tissue that covers the entire muscle and is located over the layer of epimysium.
Myofibrils contain :-
Myofibrils are composed of long proteins including actin, myosin, and titin, and other proteins that hold them together. These proteins are organized into thick and thin filaments called myofilaments, which repeat along the length of the myofibril in sections called sarcomeres. Muscles contract by sliding the thick (myosin) and thin (actin) filaments along each other.
Cross bridge are formed during :-
In the context of muscular contraction, a cross-bridge refers to the attachment of myosin with actin within the muscle cell. All muscle types - whether we're talking about skeletal, cardiac, or smooth - contract by cross-bridge cycling - that is, repeated attachment of actin and myosin within the cell.
Hence, cross bridge is formed during muscle contraction.
Time between two successive contraction :-
A refractory period is a period of time during which an organ or cell is incapable of repeating a particular action, or (more precisely) the amount of time it takes for an excitable membrane to be ready for a second stimulus once it returns to its resting state following an excitation.
During contraction of muscles :-
Sliding Filament Theory of Contraction
During muscle contraction the thin actin filaments slide over the thick myosin filament.
When Calcium is present the blocked active site of the actin clears.
Purkinje fibres :-
The specialized cardiac muscle fibers forming a network in the ventricular walls that conduct electric impulses are responsible for the contractions of the ventricles.
Mitochondria in cardiac muscles :-
Cardiac muscle cells or cardiomyocytes are the muscle cells (myocytes) that make up the cardiac muscle. Cardiomyocytes have a high mitochondrial density in comparison to other muscles fibre, which allows them to produce adenosine triphosphate (ATP) quickly, making them highly resistant to fatigue.
SA Node is :-
The SA node which is a group of specialized muscle fibres is the heart's natural pacemaker. The SA node consists of a cluster of cells that are situated in the upper part of the wall of the right atrium (the right upper chamber of the heart). The electrical impulses are generated there. The SA node is also called the sinus node.
Rigor mortis is :-
Rigor mortis is stiffening of the joints and muscles of a body a few hours after death, usually lasting from one to four days. Rigor mortis usually sets in within four hours, first in the face and generally smaller muscles
Red muscle fibres are more in :-
Red muscles are skeletal muscles that are rich in capillaries, myoglobin, and mitochondria. Capillaries are very small blood vessels that deliver oxygenated blood to the muscles. This oxygen is taken up by a protein called myoglobin. The myoglobin then helps provide the oxygen to the mitochondria, the sort of power plant of the cell. They use oxygen, among other things, to produce a lot of energy.
Unstriped muscle are also known as :-
Unstriped muscles has no striation, so they are called smooth muscles.
They are present in the internal body organs, so they are called as visceral muscles.
They are not voluntary control like skeletal muscles, so they are called Involuntary muscles.
Myo fibres also known as :-
Sarcostylets is myo fibres and is one of many contractile filaments that make up a striated muscle fiber.
Contractile unit of muscle fibres :-
The Basic Contractile Unit of Muscle. A sarcomere is the basiccontractile unit of muscle fiber. Each sarcomere is composed of two main protein filaments—actin and myosin—which are the active structures responsible for muscular contraction.
One of following has contractile properties :-
Actin, protein that is an important contributor to the contractile property of muscle and other cells.
Epimysium of muscle are made up of :-
Epimysium of Muscles are made up of white fibrous connective tissue while Perimysium and endomysium are made up of areolar tissue.
Myosin filament appear dark under microscope due to :-
Myosin filaments are thick, consisting mainly of the protein myosin. The thin actin filaments consist mostly of the protein actin; they also contain the proteins tropomyosin and the troponin complex that regulate the actin filaments interaction with myosin filaments. The filaments overlap lengthwise in the muscle fibers, producing the pattern of transverse bands or striations characteristic of striated muscle. The striations of striped muscles result from the fact that the thick and thin filaments have different refractive indices in the light microscope. Thus, myosin filaments appear dark.
Isotonic contraction takes places during :-
An isotonic contraction occurs when tension in the muscle remains constant despite a change in muscle length. Lifting an object off a desk, walking, and running involve isotonic contractions.
Largest muscle is :-
The Gluteus Maximus is the largest muscle in the human body. It is large and powerful because it has the job of keeping the trunk of the body in an erect posture. It is the chief antigravity muscle that aids in walking up stairs.
Cori cycle relationship between the :-
In the Cori cycle, lactate accumulated in the muscle cells is taken up by the liver. The liver performs a chemical process known as gluconeogenesis, to convert lactate back to glucose. This first converts lactate to pyruvate, and then finally into glucose.
Papillary muscle found in :-
The papillary muscles are muscles located in the ventricles of the heart. They attach to the cusps of the atrioventricular valves (also known as the mitral and tricuspid valves) via the chordae tendineae and contract to prevent inversion or prolapse of these valves on systole (or ventricular contraction). The papillary muscles constitute about 10% of the total heart mass.
Flight muscles of bird :-
Birds power flight primarily by large pectoralis muscles that depress the wings at the shoulder.
Contraction of shortest duration is of :-
Lactic acid is transported by blood to liver where it is converted to glycogen. Chemical energy is changed into mechanical energy during muscle contraction. The contraction of muscles of shortest duration is seen in eye lids. Shivering in cold is a method for production of heat by muscle contraction.
ATP-ase activity found in :-
In all myosins, the head domain is a specialized ATP-ase that is able to couple the hydrolysis of ATP with motion. A critical feature of the myosin ATP-ase activity is that it is actin-activated. In the absence of actin, solutions of myosin slowly convert ATP into ADP and phosphate.
Total No. of muscles in our body is :-
There are total 639 muscles in human body.
Smallest muscle is ‘stapedis' found in middle ear attached with stapes (smallest bone).
Largest muscle is ‘glutious maximus' also it is the most powerful muscle of human body.
Longest smooth muscles are :-
During pregnancy, the smooth muscle of uterus expands and attains maximum size and thus becomes largest smooth muscle.
Strongest muscles :-
There are many strong muscles and muscle groups in the human body: the tongue, jaw, eye, heart, leg, uterus, etc.
Hence the answer is (D)
Muscles of Iris & Ciliary body originate :-
The neural tube ectoderm gives rise to the retina, the iris and ciliary body epithelia, the optic nerve, the smooth muscles of the iris, and some of the vitreous humor. Surface ectoderm gives rise to the lens.
Multi unit muscles Fibres found in :-
Multi Unit :-Muscle fibres occur in small groups which are innervated separately and contract independently. A muscle has, therefore, a number of small units. Multi-unit smooth muscles are found in
(i) Nictitating membrane (iris)
(ii) Pilomotor muscle in the hair follicle.
Cardiac muscles Fibres :-
Cardiac muscle is found only in the walls of the heart. When cardiac muscle contracts, the heart beats and pumps blood. Cardiac muscle contains a great many mitochondria, which produce ATP for energy. This helps the heart resist fatigue. Contractions of cardiac muscle are involuntary, like those of smooth muscle. Cardiac muscle, like skeletal muscle, is arranged in bundles, so it appears striated, or striped.
Hence, the answer is (D)