Muscle System Flashcards
What are the three different types of muscles?
Skeletal, cardiac, smooth
Muscles are one of four….
Main tissues of the body
Where is the one place the cardiac muscle is found?
In the heart
Where are smooth muscles found?
Eyes, reproductive tract, lungs, bladder, intestines and stomach
What do smooth muscles control?
Unconscious functions of the internal body to keep us working properly
What do skeletal muscles do?
Control our movement of bones and limbs
The ________ system gives orders, the ________system carries them out?
Nervous, muscle
What is gross anatomy?
Features you can see with the naked eye
The thick, central portion of muscles
Belly
What attaches muscles to bones?
Tendons
The more stable site of attachment in muscle that does not usually move when muscles contract?
Origin of the muscle
The site of muscle attachment, usually more distal, that does all the moving?
Insertion of the muscle
What are cutaneous muscles?
Skin muscles
What are head and neck muscles responsible for?
Eye, ear, facial expressions, chewing, supporting the head and moving the neck
Why do flexor muscles of the neck and head not have to be strong?
Gravity helps
What are abdominal muscles responsible for?
Protecting organs, arching our back, vomiting, defecation, urinating, regurgitation
What are thoracic limb muscles responsible for?
Limb functions and movements
What are pelvic limb muscles responsible for?
Hip movement, movement (walking and running)
What do muscles of respiration do?
Push air in and out of the lungs
What are unique about skeletal muscle anatomy?
They are large, skinny but long, have more than on nucleus
What are myofibers?
Make up muscle fibers (tightly packed together muscles)
Two main particles that make up myofibers?
Actin and myosin filaments
Process of a muscle shrinking?
Atrophy.
Place where motor nerve functions attach to muscle fibers?
Neuromuscular function
What is a motor unit?
One nerve fiber and all muscle fibers attached to it?
Why are there so many muscles attached to one nerve?
There would need to be many nerve impulses to control the body
Fat deposits visible in meat
Marbling
Myosin fibers overlap a little during _________ but overlap in cross bridges during _________
Relaxation, contraction
The idea of a muscle contracting completely when it receives a nerve impulse or not contracting at all
All or nothing principle
What is muscle memory?
The ability for your nervous system to remember the power and movement necessary to do specific activities
The “pacemaker”
Sinoatrial node (SA node)
Why does the pacemaker have such control over things?
It’s rate is so much faster
What do sympathetic nerves control?
Stimulate the heart to beat faster and harder (fight or flight)
What are parasympathetic fiber nerves responsible for?
Inhibiting cardiac function
Why is the smooth muscle an unconscious muscle?
It is involuntary.
What are the two main gross anatomy forms of the smooth muscle?
Large sheets of cells in organs and small discrete groups of cells
How are smooth muscles shaped?
Small and spindled with one nucleus
Where are visceral smooth muscles found?
In the walls of soft, internal organs
How are smooth muscles like cardiac muscles?
The nerve supply is not required to initiate contractions, but only modifies them–they contact without the need for external stimulation
Where are multi unit smooth muscles found?
In small, delicate places like the iris, small passageways in the lungs, walls of blood vessels
Four properties of muscle?
Excitability, contractibility, extensibility, elasticity
What is excitability?
Responses to neurotransmitters
What is extensibility?
The ability to stretch without tearing
What is elasticity?
Can return to regular shape after being stretched
Where are intercalated disks found?
At the ends connecting cardiac muscle cells
Which two muscle types are striated?
Cardiac and skeletal muscles
What are the two types of smooth muscles?
Visceral and multi unit smooth muscles
What are visceral smooth muscles in charge of?
Wave like contractions (digestion)
What are multi unit smooth muscles responsible for?
Small contractions (eye twitching)
Thick central portion of the muscle
Belly
Connective tissue that connects muscle to bone
Tendon
Connective tissue that attaches bone to bone
Ligament
Sheets of connective tissue that attaches muscle to bone or muscle to muscle
Aponeurosis
A ring of muscle
Sphincter
Connective tissue on external surface of muscle
Fascia
Surrounds the entire muscle
Epimysium
Surrounds bundles of 10-100 muscle fibers
Perimysium
Separates individual muscle cells/fibers
Endomysium
Bundles of muscle tissue
Fascicles
What does calcium do to the binding sites before contracting?
Removes “mittens” from binding sites so “Shannon” can hold on
What supplies energy for the ratcheting of contracting muscles?
ATP
What pulls calcium out of the triad to supply calcium for contracting?
Acetal Coline
Enzymes that breaks down acetal Coline to stop it from dumping out calcium.
Acetal Coline esterase (ach ese)
What do prostaglandins do?
Control inflammation, regulating blood supply to kidneys, maintaining estrus, maintaining GI tract health
Thick filaments of muscle
Myosin
Thin muscle fibers
Actin
The filament that covers binding sites that won’t let myosin and actin “hold hands” to contract
Tropamyosin
Three stages of contractions?
Excitation, contraction, relaxation
The amount of Ca in the muscle is determined by level of Ca in….
Blood
Signs of hypercalcemia?
Lethargy, PU/PD, muscle weakness
Signs of hypcalcemia?
Tremors and weakness, ataxia, inability to stand
Where is sacrolemma?
Cell membrane
What is rigor mortis?
Stiffness of death- muscles contraction and can’t relax again
What exposes the contraction binding sites that allow actin and myosin heads to hold hands?
Calcium
During relaxation, what pumps Ca back into the storage area to cover up binding sites again?
Active transport pump
Why is ATP present in contraction?
Is the energy that moves myosin to attach to actin and ratchet the muscle to make the fiber appear shorter
Three sources of ATP in muscles?
Aerobic cellular respiration, ADP to ATP, anaerobic respiration
How do we control the strength of muscle contractions?
Control the number of muscle fibers that contract
What is muscle tone?
Muscle ability to be firm without physically contracting (legs, neck staying up)
What is atrophy?
Wasting away of muscles
What is hyper trophy?
Increase in diameter of muscle fibers
How do muscles create heat?
Shivering
How do cardiac muscles move?
In a wave like function to send messages
How many nucleus does a cardiac muscle have?
One
What are visceral movements responsible for?
Big movements-your but
What are multi unit smooth muscles responsible for?
Small movements
