1. every human body has an uncountable number of this basic unit of a muscle known as the: (1 point) a) muscle fibers b) ligaments

1:  muscle fibers 2:  Endurance activities3:  a motor unit 4:  All or none principal 5: Striated muscles6: Smooth muscles 7:  Cardiac muscles

The following are the correct answers to each question:Option A, muscle fibers. Skeletal muscle is made up of bundles of individual muscle fibers.Option B, endurance activities. There are two types of muscle fibers; fast-twitch and slow-twitch. Slow-twitch muscle fibers are necessary for aerobic exercises which involve low levels of exertion but with high level of endurance.Option A, a motor unit. A motor unit consists of one neuron and all of the muscle fibers that it innervates. Option D, all or none principle. The all or none principle states that the strength by which a muscle fiber responds to a stimulus is independent of the strength of the stimulus. If that stimulus exceeds the threshold potential, the nerve or muscle fiber will give a complete response; otherwise, there is no response.Option A, striated muscles. It is a muscle tissue in which the contractile fibrils in the cells are aligned in parallel bundles and come in pairs, so that their different regions form stripes visible in a microscope. Muscles of this type are attached to the skeleton by tendons and are under voluntary control.Option C, smooth muscles. It is a muscle tissue in which the contractile fibrils are not highly ordered, occurring in the gut and other internal organs and not under voluntary control.Option B, cardiac muscle. Cardiac muscle (also called heart muscle or myocardium) is one of three types of vertebrate muscles, with the other two being skeletal and smooth muscles. It is an involuntary, striated muscle that constitutes the main tissue of the walls of the heart.

is seen belowExplanation: a) Isometric contraction is any contraction of muscles where little or no movement occurs. During this phase muscle tension is present but the muscles do not change length. The muscles involved here is the abdominal muscle (Transversus abdominis, multifidus, internal oblique, pelvic floor which is a deep abdominal muscles, close to the spine and the rectus abdominis. Another muscle involved is the erector spinae muscles which is along the back and the spine. This muscles produce an isometric counter-tension to stabilize the pelvis and the trunk of the body.b) Concentric contraction is when the muscle length decreases to perform a movement. This would be the rising phase in squat.During the Concentric phase enough force is generated for your muscles to work against opposing forces and produce movement. The the knee and hip joint movements occurring during this phase includes: *Hip extension*Knee extension*Ankle plantarflexionThe muscles involved are; • Gluteus maximus and the hamstrings (i.e., the long head of the biceps femoris, the semitendinosus, and the semimembranosus). The extensor head of the adductor magnus. They work with the hip during extension. • Quadriceps femoris muscle group (rectus femoris, vastus lateralis, vastus medius, and vastus intermedius) act on the knee.• Gastrocnemius, soleus, and plantaris muscles act during ankle plantarflexion.c) Eccentric motion is when a muscle is lengthened during contraction. The eccentric movement happens during the downward phase of the squat motion as you slowly lower your body, when we squat. The the knee and hip joint movements occurring during this phase includes: *Hip flexion*Knee flexion*Ankle dorsiflexion The muscles involved are; • Gluteus maximus ( the largest but muscle) and hamstring muscles (Biceps femoris, semitendinosus, semimembranosus) works from the hip.• The quadriceps (Rectus femoris, vastus lateralis, vastus medialis oblique, vastus intermedius) works eccentrically at the knee. • The calf muscles, ankle flexors and posterior tibialis work eccentrically at the ankle.

1. muscle fibers2.endurance activities3.  all or none principle4. skeletal muscleshope this helps ?

b. striated voluntary muscle

C. Bones provide structure and support to the body, while bones move the muscles.Explanation:The muscular nor skeletal system send signals to the body. This job belongs to the nervous system. Muscles cannot offer the same amount of support and structure to the body that the skeletal system can. However, muscles can contract and relax to move.~Hope this Helps!~

Correct DThe skeletal system supports and protects the body while the muscular system is responsible for the movement. These two systems work together for movement, protection, mobility, stability etc.

first Q answer is smooth muscle second Q answer is striatedthird Q answer is skeletal

number 5 is skeletal muscles

the answer is diaphragm