Muscle Tissue Types and Functions

Flashcards about muscle tissue types and functions

What are the three types of muscle tissue in the body?

Skeletal muscle, smooth muscle, and cardiac muscle

What are the characteristics of skeletal muscle?

Striated and responds to voluntary commands from the nervous system

What is cardiac muscle?

A special type of striated muscle found only in the myocardium of the heart, with branching fibers connected by intercalated discs for synchronized involuntary contraction.

What are the characteristics of smooth muscle?

Nonstriated and contracts involuntarily in peristaltic waves

What is the epimysium?

A layer of connective tissue that protects each skeletal muscle.

What are fascicles?

Muscle fibers grouped into bundles.

What are myofibrils?

Units where proteins within a muscle cell are organized.

What are thick filaments made of?

Myosin protein molecules.

What are thin filaments mainly made of?

Actin protein molecules.

What are sarcomeres?

Repeating segments that thick and thin filaments are organized into.

What are Skeletal muscle fibers?

Long, cylindrical, striated, and multinucleate cells, called myocytes, composed of sarcoplasm and numerous rod like myofibrils and enclosed in sarcolemma.

At the neuromuscular junction how are action potentials transmitted?

Somatic motor neurons transmit action potentials through the transverse tubules of the sarcolemma to skeletal muscle fibers, causing voluntary contraction that moves the attached bones and skin.

What are Smooth muscle fibers?

Spindle shaped, non striated, and uninucleate cells called myocytes composed of thick, thin, and intermediate filaments.

What does the structure of single unit smooth muscle allow?

Action potentials from autonomic motor neurons to spread among the myocytes, producing an involuntary, coordinated contraction

What is multi unit smooth muscle?

Individual myocytes with their own motor neuron terminals.

What does the contraction of these muscle layers create?

Motion, which aids indigestion and movement of food through the stomach.

What does the tunica media have?

Smooth muscle and elastic fibers that contract and relax to constrict and dilate the lumen, thus regulating blood flow and blood pressure.

What are cardiac muscle fibers?

Short, branched, striated, and uninucleate cells that compose the myocardium of the heart wall.

What connects cardiomyocytes?

Intercalated discs.

What do intercalated discs contain?

Desmosomes and gap junctions.

What does the axial skeleton comprise?

The bones of the vertebral column, the thoracic cage, and the skull and head region

What does the appendicular skeleton consist of?

The 126 bones of the upper limbs and lower limbs and bones of the shoulder girdle and pelvic girdle that append the limbs to the axial skeleton.

What are the external intercostals?

Muscles of the thorax that extend from the tubercles in the posterior part of the ribs to the cartilages in the anterior part of the ribs.

What is the alimentary canal?

A musculomembranous tube that extends from the mouth to the anus.

What does aids digestion and neutralizes acid in the duodenum?

Digestion and neutralizes acid.

What occurs in the colon?

The majority of water reabsorption occurs and stools form, these pass into the rectum to be expelled through the anal canal at the anus

What does branching the bronchi result in?

Secondary and tertiary bronchi that in turn subdivide into bronchioles.

What do progressively smaller airways do?

Deliver oxygen rich air to the lungs, where gas exchange occurs in tiny air sacs called alveoli.

What does the systemic circulation deliver?

Oxygenated blood from the left ventricle throughout the body and deoxygenated blood from the body into the right atrium of the heart.

What do the kidneys perform?

Blood filtering

What does the urinary system consist of?

The kidneys, the ureters, the urinary bladder, and the urethra.

What do the internal genitalia of the female reproductive system consist of?

Ovaries, the uterine tubes, the uterus, and the vagina.

What is Pectoralis major composed of?

The clavicular, sternocostal, and abdominal heads.

What is the brachial plexus responsible for?

Cutaneous and muscular innervation of the shoulder and upper limb

What branches from the axillary artery?

Thoracoacromial trunk

What are the distinct steps to each electrical impulse?

The steps are: one) Initiation of the electrical impulse at the sinoatrial node two) The pause of the impulse at the atrioventricular node three) The passage of the impulse into the bundle of his four) the branching of the signal into the bundle branches of each ventricle five, the culmination of the signal at the Purkinje fibers.

What is the myocardium made up of?

Striated muscle fibers