Muscle Anatomy And Histology Flashcards
What are the three types of muscle?
Skeletal, Cardiac, and Smooth
What are features of Cardiac Muscles?
They push blood through arteries and veins
The have rhythmic contractions
What are features of Smooth Muscles?
They push fluids and solids through the body
They are under involuntary contraction
What are the 4 basic properties of muscles?
Excitability (respond to stimuli)
Contractility (ability to shorten)
Extensibility (ability to stretch)
Elasticity (ability to rebound toward original length)
What are the functions/Features of Skeletal Muscles?
-Skeletal movements
-Maintain posture and body position
-Support soft tissues
-Regulate entry and exit (Swallowing, Defecation, Urination)
-Help maintain body temp
-Under voluntary control
What converges to form tendons?
Epimysium, Perimysium, Endomysium
The chemical communication between a nerve and a muscle takes place at the what?
Neuromuscular Junction
What are the parts of the muscle?
Myofilaments
Myofibrils
Sacromeres
Sarcoplasm/Sarcoplasmic reticulum
Muscle fascicle
Muscle fibers/Satellite cells
Endo-, Peri-, and Epi- mysium
What are facts about Myofibrils?
-They are made of Myofilaments (Actin [Thin filament], Myosin [Thick filament]
-They are arranged in units of sarcomeres
What are facts of Sarcomeres?
They are the functional unit of muscle fibers
There are about 10,000 sarcomeres per Myofibrils
They contain overlapping actin and myosin
They create striations
What are the levels of organization of skeletal muscle from smallest to biggest?
Sarcomere
Myofibril
Muscle fiber
Muscle fascicle
Skeletal muscle
What is rigor mortis?
When lack of ATP causes the inability to relax muscles
What is the neurotransmitter that helps facilitate muscle contraction?
Acetylcholine (Ach)
Where are calcium ions stored in the muscle?
The sarcoplasmic reticulum
What is the relationship between control and muscle fibers?
The more precise the control the less muscle fibers are controlled by a motor neuron and vise versa
What is muscle hypertrophy?
An increase in muscle mass
What is muscle atrophy?
Decrease in muscle mass due to lack of use (Ex. Broken leg, Paralysis, etc)
What is muscle tone?
The tension of a relaxed muscle that stabilizes position of bones and joints
What are the three types of skeletal muscles?
Fast fibers
Intermediate fibers
Slow fibers
What are features of fast fibers?
-Large diameter
-High glycogen reserves
-Few mitochondria
-Anaerobic metabolism
-Fatigue easily
-Powerful contractions
-Lead to hypertrophy
Features of slow fibers?
-Small diameter
-Slow acting but long lasting
-Abundant myoglobin
-Use aerobic metabolism
-Large network of capillaries
What are the four ways to classify skeletal muscle by arrangement?
-Parallel (Ex. Biceps)
-Convergent (Ex. Pectoralis)
-Pennate (Unipennate, Bipennate, Multipennate)
-Circular (Ex. urethral sphincter)
What does Origin mean in muscle terminology?
It’s the point of the muscle that remains stationary
What does Insertion mean in muscle terminology?
The point of the muscle attachment that’s moveable
What does Action mean in muscle terminology?
The function of the muscle upon contraction
What are the 4 types of primary actions of muscles?
-Prime movers (Agonists) (Responsible for producing a particular movement)
-Antagonists (Oppose agonist)
-Synergists (Assist the prime mover)
-Fixators (Hold bone in place)
