Muscular Tissue Flashcards
How does Muscular Tissue contribute to Homeostasis?
It does this by moving substances through the body, producing movements and producing heat for normal body temp.
How much of a persons body weight is muscle?
About 40 - 50% of a persons total bodyweight.
What does Muscular strength reflect?
It Reflects “The primary function of muscle, the transformation of Chemical energy into mechanical energy to generate force…”
What are the types of Muscular Tissue?
There are 3 types of Muscular tissue:
Skeletal, Cardiac & Smooth.
What differs in each type of Muscular tissue?
They all differ on the microscopic level and are controlled by the Nervous system and Endocrine system in different ways.
Where does the name for Skeletal muscle tissue come from?
It gets its name because most of the Skeletal Muscle tissue moves the bones of the Skeletal System.
What does it mean for a Muscle tissue to be “Striated”?
This means that the Muscle tissue contains “striations”, the light and dark protein bands that can be seen under a microscope.
What are “Striations”?
Alternating Light and Dark protein bands that can be seen under a microscope.
What type of Muscle Tissue is Cardiac Tissue?
The Cardiac Muscle tissue is also striated along with Skeletal Muscle.
What type of action does the Cardiac muscle undergo?
This type of muscle tissue undergoes “Involuntary” contraction.
Where is “smooth Muscle tissue” Located in the body?
It is located in the walls of hollow internal structures.
Such as:
Blood vessels, airways & most organs of the Abdominal-pelvic cavity.
Does Smooth muscle tissue contain Striation like Cardiac and Skeletal Muscle tissue?
No it does not contain these structures, For this reason this type of tissue looks “Non-striated” and is referred to as Smooth.
What are the functions of Muscular Tissue?
Producing body movements, Stabilizing body positions, Storing and moving substances within the body, Generating Heat.
What are the Properties of Muscular tissue?
Electrical Excitability, Contractibility, Extensibility, Elasticity.
These properties allow for muscular tissue to contribute to Homeostasis.
What is Electrical Excitability?
This is the ability to respond to certain stimuli by producing electrical signals called “Action potentials”.
What are “action potentials” referred to in muscles as?
They are called “Muscle Action Potentials” & those in nerve cells are called “Nerve Action potentials.
What are the 2 types of stimuli that can trigger an action potential in the muscular tissue?
“Auto rhythmic electrical signals” & “Chemical Stimuli”.
What are Auto rhythmic Electrical Signals triggered by?
These are Action Potentials that arise from the muscle tissue itself.
Such as the hearts pacemaker.
What are chemical Stimuli in the Muscular tissue?
These are chemical changes that create action potentials in the muscular tissue.
Such as: neurotransmitters released by neurons, hormones distributed by blood, or even local changes in the ph.
What is the Property of the Muscular tissue “Contractibility”?
This is the ability of the Muscle to contract forcefully when stimulated by an action potential.
What is “Force of Contraction”?
This is when a Skeletal Muscle Contracts and generates tension while pulling on its attachment point.
What happens to the Muscular Tissue if the Tension created is great enough to overcome the resistance of an object to be moved?
The Muscle shortens and Movement occurs.
What is the Muscular Tissue property “Extensibility”?
This is the ability of the Muscle tissue to stretch, within limits, without being damaged.
What in the Muscular Tissue limits the range of extensibility and keeps it within the contractile range of the muscle cells?
The connective tissue in the Muscular tissue maintains this.
What is the Property of Muscular tissue “Elasticity”?
This is the ability of the Muscular tissue to return to its original length & shape after contraction or extension.
Skeletal Muscle is a separate organ composed of What Structures?
The Skeletal muscles are made of Cells called Fibres.
What is Superficial Fascia within a skeletal muscle?
This is a Loose connective tissue & fat underlying the skin.
what is Deep Fascia within a Skeletal Muscle?
Dense irregular connective tissue around the muscle.
What are the connective tissue components of a Skeletal Muscle?
Epimysium: Surrounds the whole muscle.
Perimysium: Surrounds bundles (Fascicles) of 10-100 muscle cells.
Endomysium: Separates individual muscle cells.
What is a Tendon?
A cord of dense connective tissue that attaches a muscle to the periosteum of a bone.
What is a Aponeuroses?
It is a tendon that extends as a broad, flat layer.
What is the nerve and blood supply for a Skeletal muscle consist of?
Each Skeletal muscle is supplied by a nerve, an artery and 2 veins.
Where are nerve fibres and capillaries found in the skeletal muscle?
They can be found in the Endomysium between individual cells.
What are Myofibres?
These are the muscle cells:
They are long, cylindrical & Muiltinucleated.
What is Sarcolemma?
This is the muscle cell Membrane.
What are Sarcolemma filled with?
They are filled with tiny threads called “Myofibrils & Myoglobin”.
What do the Skeletal Muscle fibres consist of?
The Skeletal muscle fibres covered by Sarcolemma consist of:
T tubules & Sarcoplasm & Myofibrils.
What are T tubules?
These are tiny invaginations of the sarcolemma that help spread the muscle action potentials to all the parts of the muscle fibres.
What is Sarcoplasm?
This is the Muscle cell cytoplasm and contains a large amount of “Glycogen” for energy production and “Myoglobin” for Oxygen storage.
What is the Anatomy of T (transverse) tubules?
T tubules are invaginations of the Sarcolemma into the centre of the cell / fibre.
They are filled with Extracellular fluid & carry muscle action potentials down into the cell.
Where do the Mitochondria lay in to Cell / Fibre of the Skeletal Muscle fibre?
They lie in rows throughout the cell near muscle proteins that use ATP during contraction.
What are Myofibrils?
Each Fibre contains “Myofibrils” that consist of thin and thick filaments. (Myofilaments)
What are Muscle Fibres filled with?
Muscle fibres are filled with threads called Myofibrils and separated by SR (Sarcoplasmic reticulum).
What is a Sarcoplasmic Reticulum (SR)?
This Encircles Each Myofibril.
They store calcium ions in a relaxed muscle.
Releases calcium ions during muscle contraction.
What portion of the Skeletal muscle is the contractile portion?
The contractile portion of the Muscle is called (Myofilaments) there are Thin and Thick Filaments that are the contractile proteins of the muscle.
What are the details of the Filaments of a Muscle?
Thick & Thin Filaments overlap each other in a pattern that creates “Striations”.
What are light “I” bands of a muscle fibre?
This region contains only Thin filaments.
What are the Filaments arranged into?
They are arranged into compartments called “sarcomeres”, separated by Z discs.
What are the supporting structures & proteins of the Thick and Thin Myofilaments?
M line, Titin and Z disc help anchor the thick and thin filaments in place.
What are the Proteins of the Muscle?
Myofibrils are built of three kinds of proteins:
Contractile proteins
Regulatory proteins
Structural proteins
What are Contractile proteins?
They are Myosin and Actin.
What are Regulatory proteins?
Turn contraction on and off and contain Troponin & Tropomyosin.
What are Structural proteins?
They provide proper alignment, elasticity and Extensibility.
They contain Titin, Myomesin, nebulin, dystophin.
What is Fibromyalgia?
This is a Chronic condition affecting the Fibrous connective tissue components of the muscle and ligaments.
How would you know if a client has Fibromyalgia? / Symptoms of the condition.
Symptoms of this condition include:
Pain that results from gentle pressure at specific points (Tender points).
Even without pressure there is some pain.
What does the Sub-cutaneous layer consist of?
The sub-cutaneous / Hypodermis layer separates muscle from skin.
It is composed of Areolar connective tissue & Adipose tissue.
What is the purpose of Fascia?
It allows for free movement of the muscles, carries nerves, blood vessels and lymph vessels.
It also fills space between muscle.
What are the 3 layers of connective tissue that extend from the fascia to protect and strengthen skeletal muscle?
Epimysium
Perimysium
Endomysium
What are Fascicles?
These are bundles of 10-100 or more muscle fibres covered in Perimysium.
What is the Epimysium?
The outer layer encircling the muscle fibre, it consist of dense irregular connective tissue.
What is the Perimysium?
It is a layer of dense irregular connective tissue surrounding bundles of 10-100 muscle fibres.
These are called Fascicles.
What is the Endomysium?
This layer penetrates the interior of each Fascicle and separates each fibre from one another.
What is the structure formed when all 3 connective tissue components stretch beyond the Muscle fibres to attach muscle fibres to periosteum to bone?
(When it extends as a rope-like structure)
This structure is called a “Tendon”.
What is the type of connective tissue from bone to muscle called (When it extends as a broad flat sheet)?
This is referred to as a “Aponeurosis”.
How many Nuclei does a mature muscle fibre have?
They have about a hundred or more each.
What is included in the Microscopic anatomy of the muscle fibre?
Sarcolemma, T tubules, Sarcoplasm, Myofibrils & (SR), Filaments, Sarcomere.
What is considered the plasma membrane of a muscle fibre/cell?
It is the Sarcolemma.
The Nuclei lay just beneath this.
How does the Muscular Action potential reach the entire muscle at relatively the same instance.
Thousands of tiny invaginations of the Sarcolemma called T tubules tunnel in from the surface towards the centre of each fibre.
Muscular Action potentials travel through the Sarcolemma into the T tubules that spread through to each fibre of the muscle.
What does the Sarcoplasm Consist of?
It includes a substantial amount of Glycogen & Myoglobin.
What can glycogen be used for?
it can be used for the Synthesis of ATP.
What does Myoglobin do for the Muscle tissue?
It stores and Realeases O2 when mitochondria need it for ATP production.
What does Myoglobin do for the Muscle tissue?
It stores and Realeases O2 when mitochondria need it for ATP production.
Where do the Mitochondria lay within to Muscle?
They lay strategically close to the contractile fibres so that ATP can be produced and quickly supplied to the contractile fibres.
What are the Structures called Filaments in Muscular tissue?
These are smaller protein structures within the Myofibrils.
Also called Myofilaments.
There are Thin and thick Filaments.
There are 2 Thin filaments for every 1 Thick.
What is the Structural protein “Titin”?
The 3rd most plentiful protein in skeletal muscle.
Connects the Z discs to the m line, helping stabilize the Thick filament position.
Can stretch.
What do Structural Proteins do for the Muscular tissue?
They help Keep thick ad thin filaments of myofibrils in proper alignment, provide elasticity, Extensibility, and link myofibrils to sarcolemma and extracellular matrix.
What does Contractile proteins do for the Muscular Tissue?
Proteins that generate force during contraction.
What does the Regulatory proteins do for the Skeletal Muscle?
Proteins that help switch muscle contraction on and off.
What is the Structural protein “a-Acitin”?
Protein of the Z disc that attaches to Actin molecules of thin filaments and to titin.
What is the Structural protein “Myomesin”?
Protein that forms the M line of a sarcomere.
Binds to titin And connects adjacent thick filaments to each other.
What is the structural protein “Nebulin”?
Protein that wraps around entire length of each thin filament.
Helps anchor thin filaments to z discs & regulates length of thin filaments during development.
What is the Structural protein “Dystrophin”?
Protein that links thin filaments of Sarcomere to integral membrane proteins in sarcolemma.
Helps transmit tension created by sarcomeres to Tendons.
What is “Muscle Hypertrophy”?
Increased production of Myofibrils, Mitochondria, (SR).
This results from very forceful, repetitive muscular activity, such as strength training.
What is “Fibrosis”?
When the number of new skeletal muscle fibres created by Satellite cells isn’t enough for the damage to the muscle.
Fibrosis occurs and Scar tissue replaces muscle fibres.
What is “Muscular Atrophy”?
This is a decrease in muscle size of muscle fibres as a result of progressive loss of myofibrils.
What is Sarcolemma?
The plasma membrane of the Muscle Cell / Fibre.
What is Transverse tubules?
Thousands of tiny invaginations of the Sarcolemma that help quickly spread the action potentials throughout the Muscle fibres.
What is Sarcoplasm?
Within the Sarcolemma there is Sarcoplasm.
The cytoplasm of the muscle fibre.
It contains (Red coloured proteins called Myoglobin).
What are Myofibrils?
The (SR) is packed with myofibrils, the contractile portion of the Muscle.
What is the definition of Skeletal musle?
Skeletal muscle is primarily attached to skeletal tissue.
Its striated and Voluntary.
Attaches to Skin, bone or fascia.
What is the definition of Cardiac Muscle?
Forms the wall of the heart.
Its Striated and Involuntary.
What is the definition of Smooth Muscle?
Local to Viscera.
Its Non striated and Involuntary.
What are Motor Neurons?
They supply multiple muscle cells and is apart of the Neuromuscular junction.
What is Each muscle cell supplied with in relation to Nerves and blood supply?
Each muscle cell is supplied with One motor neuron terminal branch & is in contact with one or two Capillaries.
Where are nerve fibres and Cappilaries found in the muscular tissue?
They are found in the Endomysium between individual cells.
What does each Muscle fibre consist of?
Each Fibre contains Myofibrils that consist of Thick and Thin Filaments called (Myofilaments).
What does the (SR) encircle?
Each Myofibril is encircled by (SR).
It helps store Calcium and release it when it is needed.
From the Centre of the Sarcomere to the Outside edge what are the sections named?
M-line, H zone, A band, Zone of overlap of A - I bands, I band, Z disc.
What does the A band consist of?
The A band contains the zone of overlap of the A - I band and M-line. Extends the entire length of the Thick filaments.
What is the H zone of a Sarcomere?
In the centre of each A band is a H zone and only contains Thick filaments.
What does troponin do as a regulatory protein?
When calcium ions bind to Troponin, it changes shape.
This moves tropomyosin away from myosin binding sites on actin & muscle contraction begins.
What does tropomyosin do as a Regulatory protein?
When skeletal Muscle fibres are relaxed, It covers myosin binding sites on actin molecules, thereby preventing myosin from binding to actin.
What do Thin Filaments contain?
They contain:
Actin, Troponin & Tropomyosin.
What is the structure Skeletal muscle made up of?
It is formed by Fascicles that contain muscle cells called fibres.
blood vessels and nerves wrapped in Epimysium.
What is a Fascicle made up of as a structure?
Bundles of muscle fibres wrapped in Perimysium.
What is a Muscle Fibre / Cell made up of as a structure?
Cylindrical cells covered in Endomysium and Sarcolemma.
Contains:
Sarcoplasm, Myofibrils, nuclei, mitochondria, T Tubules, (SR). The fibre has a Striated appearance.
What are Myofibrils made up of as a structure?
Threadlike contractile elements within Sarcoplasm of muscle fiber that extend entire length of fiber.
Composed of Filaments.
What are the Myofilaments of a Myofibril made up of?
They are composed of Structures called Sarcomeres.
The sarcomeres are made of Contractile proteins, Actin and Myosin.
What can Exercise do to the Myofilament of a Myofibril of a muscle Fiber?
Torn Sarcolemma
Damaged Myofibrils
Disrupted Z Discs
What are Supporting structures of a Myofibril that help anchor Thick and thin Filaments in place?
Things such as:
Titin, M-line & Z discs help anchor Thick and Thin Filaments in place.
When muscle contraction occurs do the Thick and Thin Filaments Change in length?
No they do not only the placement of them.
