Chapter 10 Muscular Tissue

A drug inhibits acetylcholinesterase. Which is the outcome?

Sodium continuously enters the cell, and spastic paralysis results.

Capillaries

microscopic vessels bring in oxygen and nutrients and remove heat and the waste products of muscle metabolism.

Eye muscles

2,3,4,6 # numbers

Which factors contribute to muscle fatigue?

ADP buildup lactic acid buildup glycogen depletion

Blood vessel diameter fluctuates between being constricted and being dilated. This is the primary contributor to blood pressure. In order for blood vessels (arterioles) to maintain a steady pressure, there must be a prolonged presence of what ion in the smooth muscle cell's cytosol?

Calcium

Three layers of connective tissue extend from the fascia to protect and strengthen skeletal muscle

Epimysium Perimysium Endomysium all three connective tissue layers may extend beyond the muscle fibers to form a ropelike tendon that attaches a muscle to the periosteum of a bone

A patient in your clinic complains of muscle pain, lack of sleep, depression, and headaches. In the exam, you notice that they are tender in certain places and confirm that you gently touching them in those places is painful. You also observe stiffness of some muscles and tendons. What type of disorder might this patient be diagnosed with?

Fibromyalgia

When a skeletal muscle is stretched, the

I band will increase.

Muscles of the thorax

Internal intercostal & External intercostal

Perimysium(around)

Layer of dense irregular connective tissue, surrounds groups of 10 to 100 or more muscle fibers, separating them into bundles called fascicles (little bundles). Many fascicles are large enough to be seen with the naked eye. They give a cut of meat its characteristic "grain"; if you tear a piece of meat, it rips apart along the fascicles.

Which statement supports length-tension relationship?

Maximal contraction occurs when there is optimal actin and myosin overlap.

Skeletal Muscle Tissue

Most move bones of body Striated - (light & dark protein bands) Voluntary controlled by neurons (nerve cells) that part of somatic(voluntary) division of the nervous system subconsciously controlled

Functions of Muscular Tissue

Producing body movements, stabilizing body positions, storing and moving substances within the body, and generating heat. Smooth ;moves, Storage is accomplished by sustained contractions of ringlike bands of smooth muscle called Sphincters, which prevent outflow of the contents of a hollow organ. Cardiac ; pumps blood to heart Skeletal ; aid the return of blood in veins to the heart Generating heat. As muscular tissue contracts, it produces heat, a process known as thermogenesis Involuntary contractions of skeletal muscles, known as shivering, can increase the rate of heat production.

Transverse (T) tubules

Thousands of tiny invaginations of the sarcolemma, tunnel in from the surface toward the center of each muscle fiber Muscle action potentials travel along the sarcolemma and through the T tubules, quickly spreading throughout the muscle fiber. This arrangement ensures that an action potential excites all parts of the muscle fiber at essentially the same instant.

Fatty acids can be used to produce ATP during

aerobic respiration

Fibromyalgia

chronic, painful, nonarticular rheumatic disorder that affects the fibrous connective tissue components of muscles, tendons, and ligaments Treatment consists of stress reduction, regular exercise, application of heat, gentle massage, physical therapy, medication for pain, and a low‐dose antidepressant to help improve sleep.

subcutaneous layer (hypodermis)

composed of areolar connective tissue and adipose tissue The adipose tissue of the subcutaneous layer stores most of the body's triglycerides, serves as an insulating layer that reduces heat loss, and protects muscles from physical trauma. Fascia is a dense sheet or broad band of irregular connective tissue that lines the body wall and limbs and supports and surrounds muscles and other organs of the body.--- Fascia allows free movement of muscles; carries nerves, blood vessels, and lymphatic vessels; and fills spaces between muscles.

Aponeurosis

connective tissue elements extend as a broad, flat sheet all three connective tissue layers may extend beyond the muscle fibers to form a ropelike TENDON that attaches a muscle to the periosteum of a bone.

Which region is the dermatome?

dermatome is at the top - forms the connective Myotome - forms the skeletal muscles of the head, neck, & limbs Sclertome - gives rise to the vertebrae

Somites develop and are arranged on either side of the

developing nervous system

Muscle Fibers

diameter ranges from 10 to 100 μm. The typical length of a mature skeletal muscle fiber is about 10 cm (4 in.), although some are as long as 30 cm (12 in.).

Bicep curls consist of patterns of what type of tension?

eccentric and concentric

Properties of Muscle Tissue

electrical excitability; For muscle cells, two main types of stimuli trigger action potentials. Autorhythmic electrical signals arising in the muscular tissue itself, as in the heart's pacemaker. The other is chemical stimuli, such as neurotransmitters released by neurons, hormones distributed by the blood, or even local changes in pH. contractility;is the ability of muscular tissue to contract forcefully when stimulated by an action potential extensibility, - is the ability of muscular tissue to stretch, within limits, without being damaged. Muscle is subject to the greatest amount of stretching. For example, each time your stomach fills with food, the smooth muscle in the wall is stretched. Cardiac muscle also is stretched each time the heart fills with blood. elasticity; is the ability of muscular tissue to return to its original length and shape after contraction or extension.

Your patient comes in with a drooping eyelid and explains that her vision has been blurry, and now she's having trouble swallowing. She is diagnosed with myasthenia gravis. What would be a good next step for this patient?

examining her thymus to see if it is tumorous or hyperplastic

Which of the following permits the rapid spread of muscle action potentials among cardiac muscle fibers?

gap junctions

Which property do cardiac and smooth muscle share?

gap junctions

Which of the following can affect smooth muscle contraction and relaxation?

hormones ph change stretching

Smooth Muscle Tissue

located in the walls of hollow internal structures - blood vessels, organs, airways, most organs in abdominopelvic cavity; in skin attached to hair follicles Non- striated that's why it's called smooth Involuntary autorhythmicity(muscles propel food through gastrointestinal tract Both cardiac muscle and smooth muscle are regulated by neurons that are part of the autonomic (involuntary) division of the nervous system and by hormones released by endocrine glands.

Muscular Tissue

make up 40-50% of total adult weight

Myosin

motor protein that can hydrolyze ATP

Somatic motor neurons

neurons that stimulate skeletal muscle to contract Each somatic motor neuron has a threadlike axon that extends from the brain or spinal cord to a group of skeletal muscle fibers. The axon of a somatic motor neuron typically branches many times, each branch extending to a different skeletal muscle fiber.

Whole muscles can respond in a graded fashion by varying the

number of motor units recruited

A single motor unit will innervate

one fiber type

Cardiac Muscle Tissue

only found in the heart; forms most of the heart wall Striated Involuntary alternating contraction and relaxation of heart is not subconsciously controlled natural pacemaker initiates each contraction- autorhythmicity(built in rhythm) hormones and neurotransmitters can adjust heart rate speeding or slowing pacemaker

Epimysium(upon)

outer layer, encircling the entire muscle. It consists of dense irregular connective tissue.

Endomysium(within)

penetrates the interior of each fascicle and separates individual muscle fibers from one another. The endomysium is mostly reticular fibers.

Muscular Tissue homeostasis

producing body movements moving substances through the body producing heat to maintain normal body temperature.

Hypertrophy occurs in

skeletal, smooth, cardiac

Myoglobin is most abundant in which skeletal muscle fiber type?

slow oxidative fiber

Myology

study of muscles

Chemical Stimuli

trigger action potential hormones neurotransmitters local changes in PH

It is conceivable that 50% of your muscle mass could be lost up to ten years prior to your notice of loss in muscle strength.

true

When muscles undergo resistance training there is trauma to the muscle cells. Which cells are present on the periphery to help repair the damaged area?

Satellite cells

Sarcolemma

The multiple nuclei of a skeletal muscle fiber are located just beneath the sarcolemma the plasma membrane of a muscle cell