fingernails and toenails are made primarily of

ATI TEAS 7

TEAS 7 practice test science

1. What are fingernails and toenails primarily made of?

A. Collagen (Collagen is found in the dermis)
B. Keratin
C. Melanin (Melanin provides pigment, not structure)
D. Sebum (Sebum is an oily substance)

Correct answer: B

Rationale: Fingernails and toenails are primarily made of a protein called keratin. Keratin is a tough, fibrous protein that provides structure and strength to nails, hair, and the outer layer of skin. Collagen, as mentioned, is found in the dermis and is not the primary component of nails. Melanin provides pigment to the skin and hair, not the structure of nails. Sebum is an oily substance produced by the skin's sebaceous glands and is not a structural component of nails.

2. Where does the majority of nutrient absorption occur?

A. Mouth
B. Stomach
C. Small intestine
D. Large intestine

Correct answer: C

Rationale: The majority of nutrient absorption occurs in the small intestine. The small intestine is where the final stages of digestion take place, and it is specialized for absorption with its large surface area and villi that increase nutrient absorption efficiency. The mouth is responsible for mechanical digestion through chewing, the stomach primarily aids in digestion through mixing and breakdown of food, and the large intestine mainly absorbs water and electrolytes, with minimal nutrient absorption.

3. Where is the ball-and-socket joint, allowing a wide range of motion, found?

A. Upper arm (humerus) and shoulder blade (scapula)
B. Collarbone (clavicle) and breastbone (sternum)
C. Two vertebrae in the spine
D. Ribs and sternum

Correct answer: A

Rationale: The ball-and-socket joint is located between the upper arm (humerus) and the shoulder blade (scapula). This joint provides a wide range of motion, enabling movements like flexion, extension, abduction, adduction, and rotation. It plays a crucial role in various activities involving the shoulder joint, such as throwing, reaching overhead, and performing rotational movements. Choice B, the collarbone (clavicle) and breastbone (sternum), form the sternoclavicular joint, which is a synovial saddle joint. Choice C, two vertebrae in the spine, typically form gliding or facet joints. Choice D, ribs and sternum, are connected by cartilage, forming cartilaginous joints.

4. What is the primary function of hematopoietic tissue?

A. Building and repairing bone
B. Supporting and connecting tissues
C. Production of blood cells
D. Contracting for movement

Correct answer: C

Rationale: The primary function of hematopoietic tissue is the production of blood cells. Hematopoietic tissue, primarily found in the bone marrow, is responsible for generating red blood cells, white blood cells, and platelets. These blood cells are vital for oxygen transport, immune response, and blood clotting. Choices A, B, and D are incorrect as they do not reflect the main function of hematopoietic tissue. Building and repairing bone is primarily carried out by osteoblasts and osteoclasts, supporting and connecting tissues is a role of connective tissues like tendons and ligaments, and contracting for movement is a function of muscle tissue.

5. Diabetic nephropathy, a complication of diabetes, affects the:

A. Ureters
B. Bladder
C. Urethra
D. Nephrons

Correct answer: D

Rationale: Diabetic nephropathy, a complication of diabetes, affects the nephrons. Nephrons are the functional units of the kidneys responsible for filtering blood and producing urine. The high blood sugar levels associated with diabetes can damage the nephrons over time, leading to kidney dysfunction and, ultimately, kidney failure. Choices A, B, and C are incorrect because diabetic nephropathy primarily impacts the nephrons in the kidneys, not the ureters, bladder, or urethra.