Exam 30: How Animals Move

When sarcomeres contract, they generate force (tension). However, the amount of force generated depends on the sarcomere length and the amount of thick and thin filament overlap. Below is a figure that details the force-generating properties of a single sarcomere. This figure was modified from a scientific paper by Al Gordon and colleagues from 1966 and is a classic illustration of the relationship between sarcomere length and force. -At what point on the graph is the sarcomere the most extended?

In rickets, lack of calcium decreases the strength of the mineral matrix of compact bone so that it is unable to

Thin sheets of ________ form a cushion-like surface for moving joints

A racehorse cannot stand on one leg, but when it runs it rarely has more than one leg on the ground. Why is a running horse more stable than a standing one?

Which animal has an exoskeleton?

Rickets is a softening of the bones that can lead to frequent fractures and skeletal deformities. The legs of a person with rickets tend to bow outward under the force exerted by body weight and movement. British scientists found a serious increase in the incidence of rickets and other bone deficiencies among women in Middle Eastern countries who cover their bodies completely to express a form of religious belief, as well as among their breast-fed children. Most of the body's vitamin D, which is necessary for calcium absorption by bone tissue, is obtained through sunlight acting on the skin. Doctors warn that women who completely cover their skin do not get enough sunlight to produce the vitamin D necessary for bone health. This lack of sun exposure also lowers the level of vitamin D in their breast milk, which means that their children may develop the same vitamin D deficiencies. Lack of calcium and phosphorous, which are needed for bone repair and replacement, can also lead to rickets. Rickets caused by a dietary lack of these minerals is more common in developing countries because dairy products and green vegetables, the best sources of calcium, are not commonly eaten. -As a physician caring for a nursing woman who has chosen to dress in a way that covers her skin but who is concerned about rickets developing in her baby, you might advise her to

Muscles are connected to bones by

When sarcomeres contract, they generate force (tension). However, the amount of force generated depends on the sarcomere length and the amount of thick and thin filament overlap. Below is a figure that details the force-generating properties of a single sarcomere. This figure was modified from a scientific paper by Al Gordon and colleagues from 1966 and is a classic illustration of the relationship between sarcomere length and force. -What portion of the graph would involve myosin forming cross-bridges and going through power strokes?

A muscle fiber from the latissimus dorsi (one of the back muscles) of a chimpanzee has a lot of mitochondria and myoglobin and can generate relatively little force. Which type of muscle fiber is being described?

The shoulder joint where the humerus meets the pectoral girdle is an example of a

Which provides a base of support for the bones of the forelimbs and hind limbs to the axial skeleton in a human?

Which list of muscle components is in the correct order from smallest to largest?

Functionally, the muscle fiber's fundamental unit of contraction is the

A motor unit is

In the year 2000, it was estimated that the number of new osteoporotic fractures in men and women ages 50 and older was 9.0 million: 1.6 million were at the hip, 1.7 million were at the forearm, and 1.4 million were from the spine and humerus. Consider the following data and answer the questions that follow. Estimated Number of Fractures (in Thousands) Worldwide at the Sites Shown in Men and Women in the Year 2000 Percentage of Site of Fracture Fractures Men Women Total Hip 18.2 490 1,137 1,627 Forearm 18.5 332 1,328 1,660 Spine 15.8 554 862 1,416 Humerus 7.9 178 528 706 Other sites 39.6 1,909 1,641 3,550 Total 100 3,463 5,496 8,959 Source: Adapted from Johnell, O., & Kanis, J.A. (2006). Osteoporosis International, 17(12): 1726. doi:10.1007/s00198-006-0172-4. -Fractures at sites other than hip, forearm, spine, and humerus were

The "Ironman" is a version of the triathlon, a race that includes three events: swimming, bicycling, and running. In an Ironman, an athlete must swim 2.4 miles, bike 112 miles, and run 26.2 miles, in that order, without a break. The annual Ironman World Championship is held in Hawaii every year. The men's course record was set in 2011 by Australia's Craig Alexander with a time of 8 hours, 18 minutes, and 37 seconds, and the women's course record was set in 2009 by England's Chrissie Wellington with a time of 8 hours, 54 minutes, and 2 seconds. -Which event of the Ironman would likely contribute the most to bone development and growth?

Which muscle(s) would have the greatest number of muscle cells per motor unit?

Which statement about locomotion is true?

Bone is composed of

Why is a newly molted crab unusually slow and clumsy?