You have been given a sample tissue that has pillar-shaped cells arranged tightly together. The tissue you have is:

Correct Answer: C

Rationale: The correct answer is C: Columnar Epithelium. Columnar epithelium is characterized by tall, pillar-like cells that are closely packed together. This arrangement allows for absorption and secretion in tissues like the digestive tract, where this type of epithelium is commonly found. Squamous epithelium (choice A) consists of flat cells, cuboidal epithelium (choice B) has cube-shaped cells, and transitional epithelium (choice D) is found in areas that need to stretch and expand, like the urinary bladder.

Correct Answer: B

Rationale: The correct statement is that skeletal muscle attaches to bones through tendons, enabling movement. Tendons connect muscles to bones and allow the force generated by muscle contraction to be transmitted to the bones, facilitating voluntary movements. Choice A is incorrect because skeletal muscle typically makes up around 40-50% of an individual's body weight, not a fixed 40%. Choice C is incorrect as muscle contraction plays a vital role in temperature regulation by generating heat. Choice D is incorrect as skeletal muscles may have constant low-level contractions even at rest, known as muscle tone.

Correct Answer: D

Rationale: The correct answer is the Achilles tendon. The Achilles tendon is a strong tendon located at the back of the human leg, connecting the calf muscles to the heel bone. This positioning makes it a posterior feature, situated at the rear of the leg. The patella, also known as the kneecap, is positioned at the front of the leg, making it an anterior feature. The quadriceps sartorius are muscles located in the front of the thigh, not at the back of the leg. Additionally, the triceps brachii is a muscle found in the upper arm, not in the leg, making it an incorrect choice.

Correct Answer: A

Rationale: In a rotator cuff tear, the most common structures torn are the tendons of the rotator cuff muscles. In severe cases, the tear may also extend to involve the surrounding ligaments. Therefore, the correct answer is A, as it accurately represents the structures that are likely to be affected in a rotator cuff tear. Choice B is incorrect as muscles are not typically torn in a rotator cuff tear. Choice C is also incorrect as ligaments are not the primary structures involved in a rotator cuff tear. Choice D is incorrect because a rotator cuff tear typically involves more than just the tendons.

Correct Answer: C

Rationale: The correct answer is C: Humerus and scapula. The rotator cuff is a group of muscles and tendons that help stabilize the shoulder joint. Specifically, the rotator cuff muscles help to stabilize the head of the humerus (the upper arm bone) within the shallow socket of the scapula (shoulder blade). This stabilizing action is crucial for maintaining shoulder joint function and preventing injuries. Choices A, B, and D are incorrect because the rotator cuff primarily stabilizes the humerus and scapula, not the radius, ulna, or clavicle.