1.
All of the following substances move in and out of cells, except:
Correct Answer
D. Blood
Explanation
Blood is not a substance that moves in and out of cells. It is a connective tissue that circulates throughout the body, transporting substances such as nutrients, gases, and waste to and from cells. Nutrients are essential for cell function and are transported into cells, while waste products are transported out of cells. Gases, such as oxygen and carbon dioxide, also move in and out of cells through processes like diffusion. However, blood itself does not directly enter or exit cells.
2.
When tissue repair begins, ________ work to form a mesh-like clot that prevents blood loss.
Correct Answer
B. Platelets
Explanation
Platelets are small, disc-shaped cells in the blood that play a crucial role in blood clotting. When tissue repair begins, platelets become activated and aggregate at the site of injury. They release various substances that promote clot formation, including clotting factors and chemicals that cause blood vessels to constrict. The mesh-like clot formed by platelets helps to seal off the damaged blood vessels, preventing further blood loss and providing a temporary scaffold for the subsequent stages of tissue repair.
3.
The dermis is the ________ layer of skin.
Correct Answer
B. Middle
Explanation
The dermis is the middle layer of the skin. It is located between the epidermis (the outermost layer) and the subcutaneous tissue (the deepest layer). The dermis contains various structures such as blood vessels, hair follicles, sweat glands, and sensory receptors. It provides strength, elasticity, and support to the skin, as well as housing important components like collagen and elastin fibers.
4.
These produce an oily substance that lubricates skin and provides protection from bacteria:
Correct Answer
A. Sebaceous glands
Explanation
Sebaceous glands are responsible for producing an oily substance called sebum, which lubricates the skin and helps to keep it moisturized. This oily substance also provides a protective barrier on the skin, preventing the entry of bacteria and other harmful substances. Sebaceous glands are found all over the body, except for the palms of the hands and the soles of the feet. They are most abundant on the face, scalp, and upper back.
5.
Ultraviolet radiation from sunlight causes skin cells to produce ________, which the liver and kidneys modify to promote bone development.
Correct Answer
C. Vitamin D
Explanation
Ultraviolet radiation from sunlight stimulates the production of Vitamin D in the skin cells. This Vitamin D is then modified by the liver and kidneys to promote bone development. Vitamin C, Vitamin A, and Vitamin B12 do not play a direct role in this process.
6.
Nails are hard plates of dead epidermal cells that have been converted into:
Correct Answer
A. Keratin
Explanation
Nails are composed of keratin, a tough and fibrous protein that forms the structure of the nails. Keratin is responsible for the hardness and durability of nails, as well as their ability to protect the sensitive skin underneath. It is a natural component of hair, skin, and nails, and is produced by specialized cells in the epidermis called keratinocytes. Melanin is responsible for skin and hair color, collagen is a protein found in connective tissues, and calcium is a mineral important for bone health. Therefore, the correct answer is keratin.
7.
The carpals of the wrist are examples of which bone type?
Correct Answer
C. Short
Explanation
The carpals of the wrist are examples of short bones because they are roughly cuboidal in shape and provide stability and support to the wrist joint. Short bones are typically found in the hands and feet, and their main function is to provide strength and allow for limited movement. Unlike long bones, short bones do not have a medullary cavity or extensive bone marrow.
8.
All of the following are long bones, except:
Correct Answer
B. Rib
Explanation
The rib is not a long bone. Long bones are characterized by their elongated shape and include bones such as the humerus, phalanges, and fibula. Ribs, on the other hand, are flat bones that form the ribcage and protect the organs in the thoracic cavity. They are not classified as long bones.
9.
Which best describes a comminuted fracture?
Correct Answer
B. The bone is crushed or shattered
Explanation
A comminuted fracture is a type of fracture where the bone is crushed or shattered into multiple pieces. Unlike other types of fractures where the bone may be partially fractured or one end of the bone is driven into the other end, in a comminuted fracture, the bone is completely fragmented. This type of fracture often requires surgical intervention to realign and stabilize the bone for proper healing.
10.
Smooth muscle can be found in which of the following systems?
Correct Answer
D. All of the above
Explanation
Smooth muscle can be found in all of the above systems (circulatory, respiratory, and digestive). Smooth muscle is a type of muscle tissue that is involuntary and non-striated. It is responsible for the movement and contraction of various organs and structures in these systems. In the circulatory system, smooth muscle lines the walls of blood vessels, helping to regulate blood flow. In the respiratory system, smooth muscle is present in the walls of the bronchioles, aiding in the control of airway diameter. In the digestive system, smooth muscle is found in the walls of the gastrointestinal tract, facilitating the movement of food through the digestive system.
11.
Which term does not belong with the others?
Correct Answer
D. Spinal nerve
Explanation
The term "spinal nerve" does not belong with the others because it is the only term that refers to a peripheral nerve, while the other terms (brain, spinal cord, CNS) all refer to components of the central nervous system.
12.
Which term is used to define a complete dislocation of a joint?
Correct Answer
C. Luxation
Explanation
Luxation is the correct answer because it refers to a complete dislocation of a joint. A luxation occurs when the bones that form a joint are completely displaced from their normal position, causing the joint to be completely out of alignment. This can result in pain, swelling, and loss of function in the affected joint.
13.
Which of these is not an endocrine gland?
Correct Answer
C. Salivary gland
Explanation
The salivary gland is not an endocrine gland because it does not secrete hormones directly into the bloodstream. Instead, it secretes saliva into the oral cavity to aid in the digestion of food. Endocrine glands, such as the pancreas and parathyroid, release hormones directly into the bloodstream to regulate various bodily functions. The testes also function as endocrine glands, producing testosterone and other hormones that are released into the bloodstream to regulate reproductive functions.
14.
Which hormone has the greatest influence on the ability to secrete milk?
Correct Answer
C. Prolactin
Explanation
Prolactin is the hormone that has the greatest influence on the ability to secrete milk. It is responsible for stimulating the development of mammary glands and milk production in females, particularly during pregnancy and after childbirth. Prolactin levels rise in response to the suckling of an infant, promoting the release of milk from the breasts. Estrogen and progesterone also play important roles in the regulation of milk production, but prolactin is the primary hormone involved in this process. Oxytocin, on the other hand, is responsible for the ejection of milk from the breasts during breastfeeding.
15.
Select the statement about red blood cells that is incorrect.
Correct Answer
C. Deoxyhemoglobin carries oxygen.
Explanation
The statement "Deoxyhemoglobin carries oxygen" is incorrect. Deoxyhemoglobin is the form of hemoglobin that has released oxygen and is carrying carbon dioxide. It is formed when oxygen binds to hemoglobin in the lungs and is transported to the tissues. Oxygenated hemoglobin carries oxygen to the tissues.
16.
The liquid portion of blood is referred to as _____.
Correct Answer
C. Plasma
Explanation
Plasma is the correct answer because it is the liquid portion of blood. It is a yellowish fluid that makes up about 55% of the total blood volume and contains various proteins, electrolytes, hormones, and waste products. Plasma plays a crucial role in transporting nutrients, hormones, and waste products throughout the body, maintaining blood pressure, and regulating body temperature. It also helps in clotting and immune response.
17.
A heartbeat of less than 60 beats per minute is called _____.
Correct Answer
B. Bradycardia
Explanation
Bradycardia is the correct answer because it refers to a heartbeat of less than 60 beats per minute. Tachycardia, on the other hand, is the opposite, with a heartbeat of over 100 beats per minute. Arrhythmia refers to an irregular heartbeat, while fibrillation specifically refers to an irregular and rapid heartbeat.
18.
Where does the greatest amount of digestion occur?
Correct Answer
A. Small intestine
Explanation
The small intestine is where the greatest amount of digestion occurs in the body. It is responsible for breaking down food into smaller molecules through the action of enzymes and absorbing nutrients into the bloodstream. The small intestine has a large surface area due to its long length and the presence of villi, which increases its efficiency in digestion and absorption. The stomach also plays a role in digestion, but the majority of digestion takes place in the small intestine. The large intestine mainly absorbs water and electrolytes, while the liver produces bile to aid in digestion.
19.
Which of these carbohydrates is not a good source of energy?
Correct Answer
C. Cellulose
Explanation
Cellulose is not a good source of energy because it is a complex carbohydrate that cannot be broken down by human digestive enzymes. While beet sugar, molasses, and fruits are all sources of simple sugars that can be easily metabolized for energy, cellulose is a structural component of plant cell walls and cannot be digested by humans.
20.
Thin-walled outpouchings of the alveolar ducts of the lungs are the ___________________.
Correct Answer
B. Alveolar sacs
Explanation
Alveolar sacs are thin-walled outpouchings of the alveolar ducts of the lungs. These sacs are responsible for the exchange of oxygen and carbon dioxide between the lungs and the bloodstream. They are composed of clusters of alveoli, which are tiny air sacs where gas exchange takes place. The alveolar sacs are crucial for efficient respiration and play a vital role in maintaining proper oxygenation of the body.