Muscular System Flashcards
what are muscles made of?
cells that can shorten or contract
what does myo stand for?
refers to muscles
What is myology?
The study of muscles
What is myositis?
inflammation of muscle tissue
What does sarco refer to?
Muscle cells
What is sarcoplasm?
The cytoplasm of a muscle cell
What are tendons?
dense fibrous connective tissue that attaches muscle to other body parts (usually bone), is poorly vascularized
What is aponeurosis?
a broad sheet of dense fibrous connective tissue, similar in structure to tendons and serve the same function
What is the retinaculum?
A band of fascia that stabilizes a tendon in place
What is the bursa?
A fluid-filled sac or pouch that functions as a gliding surface to reduce friction between tissues such as tendon and bone
What is a tendon sheath?
Like a bursa that wraps around a tendon and performs the same function
What are motor units?
the physiological unit of muscle contraction
Describe smooth muscle.
non-striated, involuntary; composed of small, spindle shaped cells that lack striation or bands and therefore appear “smooth”. Each cell has a centrally located nucleus.
Where is smooth muscle located?
in the walls of hollow organs such as the esophagus, stomach, intestine, colon, blood vessels, and bladder; also in skin attached to hair and in the iris of the eye
What is the function of smooth muscle?
It moves food through the digestive tract, regulates the size of an organ, controls light entering the eye, moves fluid through vessels, and causes hair to stand erect
Describe cardiac muscle.
Striated, involuntary; cells are cylindrical and branched with a single centrally located nucleus. Cells form an intricate network and are connected by intercalated disks (specialized type of gap junction)
Where is cardiac muscle found?
only in the heart
What is the function of cardiac muscle?
pumps blood through the vascular system
Describe skeletal muscle.
Striated, voluntary; cells are striped, long, and cylindrical, each one with multiple eccentrically placed nuclei
Where are skeletal muscles located?
Attached to bone and occasionally to skin, eyeballs, and upper part of the esophagus
What is the function of skeletal muscles?
voluntary movement of body, including movement of the eyes and the initial part of swallowing. Produce skeletal muscle, maintain posture and body position, support and protect soft tissues, guard entrances and exits of digestive and urinary tracts, maintain body temperature
What is the anatomy of a skeletal muscle?
Muscle tissue (skeletal muscle cells or fibers), connective tissue (dense), nerves, blood vessels, adipose tissue (marbling)
What are the three layers of connective tissue?
epimysium, perimysium, endomysium
Where is the epimysium?
surrounds the entire muscle
Where is the perimysium
divides the entire skeletal muscle into a series of compartments (fascicle)
Where is the endomysium?
Surrounds the individual skeletal muscle fibers and interconnects adjacent muscle fibers
What do the three layers of connective tissue make?
The collagen fibers in the three layers come together to form a bundle (tendon) or a broad sheet (aponeurosis)
What is a neuromuscular junction?
Motor nerves synapse on muscle fibers, a motor unit is the nerve fiber and all the muscle fibers it innervates
What results in atrophy?
lack of nervous supply (without nutrition)
What is electromyography?
recordings (and timing) of electrical activity during muscle contraction to an electric stimulus
What are the muscles of the vertebral column?
epaxial muscles and hypaxial muscles
What are epaxial muscles?
extensors of the vertebral column
What are hypaxial muscles?
flexors of the neck
What are the muscles of the thoracic wall?
intercostal muscles and diaphragm
What are the muscles of the abdominal wall?
external abdominal oblique, internal abdominal oblique, transverse abdominus
What are the two muscles of the neck that outline the jugular groove?
sternocephalicus and brachiocephalicus
Where is the sternocephalicus?
on the ventral border of the jugular groove
Where is the brachiocephalicus?
On the dorsal border of the jugular groove
What is an exception to the jugular groove muscles?
llama, their cranial neck skin is thick and the jugular is covered by muscle. This is called a blink stick
What are the regions of the muscles of the forelimb?
shoulder, brachium, antebrachium, manus
What is the thoracic girdle?
muscles joining the forelimb to the trunk
What are the regions of the hindlimb?
hips, thigh, crus, pes
