Exam 3 Flashcards
What are the characteristics of muscle tissue
Excitability, contractibility, extensibility, and elasticity
What are the primary functions of muscle
Provide motion, maintain posture, and generate heat
What happens to skeletal muscle when damaged
It is repaired or replaced by connective tissue new skeletal muscle fibers are not formed
What happens to skeletal muscle if the nerve supply to the muscle is destroyed
The muscle atrophies
What is a fascicle
A bundle of muscle fibers
What is the endomysium
A connective sheath that covers each muscle fiber
What is the perimysium
Connective sheath that covers a fascicle
What is the epimysium
Connective sheath that covers the entire muscle
What is the fascia
Binds muscles to each other and keeps them in position and separates them
What is the deep fascia
Surrounds a group of muscles and goes in btw the ind muscles
What is superficial fascia
Loosely connected to muscle and is usually next to the skin
What is the belly of the muscle
The thickest part of the muscle
What is a digastric muscle
If the muscle is divided by an intermediate tendon so that it actually has 2 bellies
What are the skeletal muscle attachments comprised of
Tendons and aponeuroses are formed from continuations of the epimysium, perimysium, and endomysium
What is aponeuroses
Attached to bones or muscles by broad sheets of fibrous tissue
What is the origin of a skeletal muscle
The more stable attachment site that does not move much when the muscle contracts
What is the insertion site for skeletal muscles
Site that undergoes the most movement when a muscle contracts
What is a agonist skeletal muscle
The prime mover that directly produces a desired movement
What is an antagonist skeletal muscle
Directly opposes the action of an agonist
What is the synergist skeletal muscle
Contracts at same time as agonist to assist its action such as the deep and superficial digital flexor muscles
What are fixator skeletal muscles
Stabilizes joints to allow other movements such as digital flexors + extensors allowing flexion of digits w/o flexing wrist
What is a synergistic action
Muscles working together to produce smooth and controlled movement indirectly aiding the action of the prime mover
What is rotation
The movement of a part around its long axis
What is circumduction
The movement of an extremity that describes the surface of a cone
What is supination
Movement of the forearm so the palmar side is rotated upward or forward
What is pronation
The movement of the palmar side of the paw or foot downward or backward
What are the characteristics that goes into the name of a skeletal muscle
Action, shape, location, direction of fibers, number of heads, and attachment sites
What is the function of the masseter muscle and where is it located
It enables mastication and is located on the side of the cheeks
What muscles are responsible for raising the head and neck
The splenius and trapezius
Where is the trapezius located
It is on the dorsal aspect of the neck
Where is the splenius muscle located
It is the most cranial muscle in the middle of the neck taking up the top 3rd of the neck
What is the function and location of the brachiocephalicus muscle
It extends the head and neck and is located on the ventral aspect of the neck
What is the function of the sternocephalicus and where is it located
It flexes the head and neck and it is ventral of the brachiocephalicus
What are the functions of the abdominal skeletal muscles
Support abdominal organs, help flex the back, participate in defecation, urination, parturition, vomiting, and regurgitation increasing intraabdominal pressure, and contributes to respiration as a fail safe
What are the layers of the abdominal skeletal muscles
External abdominal oblique muscle, internal abdominal oblique muscles, rectus abdominis, and transversus abdominis
What is the linea alba
The left and right parts of the abdominal muscles that come together in the center of the abdomen
What is the function of the thoracic limb skeletal muscles
Functions mainly for locomotion
What are the adductor muscles in the thoracic limb
Latissimus dorsi (pull up) and pectoral muscles (bear hug)
What is the abductor muscle in the thoracic limb
Deltoid muscle (shoulder caps)
What are the brachial muscles
Biceps brachii and triceps brachii
What are the carpal and digital muscles
Extensor carpi radialis and deep digital flexor
Where is the latissimus dorsi muscle located
Runs along the craniodorsal part of the abdomen
Where is the deep pectoral muscle located
It is on the cranioventral aspect of the abdomen near the thoracic limb
Where is the ulnar carpal flexor and extensor muscle
On the caudal side of the thoracic limb
Where is the extensor muscles of carpus and digits
On the cranial aspect of the thoracic limb
Where are the triceps muscles located
Proximal to the extensor and ulnar muscles
Where are deltoid muscles located
Cranial to the tricep muscles near the point of the shoulder
What is the function of the pelvic limb skeletal muscles
Locomotion
What are the extensor muscles in the hip joint
Gluteal muscles and hamstring muscle group
What are the muscles in the hamstring muscle group
Biceps femoris, semimembranosus muscle, and semitendinosus muscle
Where is the biceps femoris
On the lateral caudal aspect of the proximal femur
Where is the semitendinosus muscle
Medial to the biceps femoris
Where is the semimembranosus muscle
Medial to the proximal end of the semitendinosus muscle
What are the extensor muscles of the stifle joint
The quadriceps femoris
What are the different parts of the quadriceps femoris
Rectus femoris, vastus intermedius, vastus lateralis, and vastus medialis
Where is the rectus femoris located
On the medial superficial aspect of the femur
Where is the vastus intermedius
Sits under the rectus femoris
Where is the vastus lateralis
On the lateral aspect of the rectus femoris
Where is the vastus medialis
On the medial aspect of the rectus femoris
What are the muscles in the tarsus and digits
The gastrocnemius muscle including the achilles tendon
Where is the gastrocnemius muscle
On the caudal aspect of the tibia and fibiula
What is the function of the skeletal muscles used in respiration
Increase and decrease size of thoracic cavity
What are the inspiratory muscles
Diaphragm and external intercostal muscles
What are the expiratory muscles
Internal intercostal muscles and abdominal muscles
What are the 3 respiration fail safes
The external intercostal muscles, internal intercostal muscles, and abdominal muscles
What are the red muscle fibers
Produce tonic contractions that are sustained over long periods of time but have little force and are aerobic such as slow twitch fibers
What are white fibers
Contract phasically w/ the strength of contraction building to a peak then relaxing and are anaerobic such as fast twitch fibers
What is a sarcolemma
The cell/fiber membrane of a muscle fiber that have invaginates w/in cell making T-tubules
What is the sarcoplasm
The cytoplasm of a muscle fiber
What does each fiber contain
Longitudinal myofibrils packed together like pencils
What is the sarcoplasmic reticulum
The endoplasmic reticulum in muscle fibers that store Ca there are a lot of these on myofibrils
What are myofibrils composed of
Actin and myosin
What is a sarcomere
Contractile units of muscle cells that are laid end to end w/in one myofibrils