Bio 201 Human Anatomy and Physiology

Correct Answer:

elastic

Explanation:

Elastic cartilage contains a dense network of visible elastic fibers in its matrix, making it both strong and highly flexible. This allows it to maintain shape while bending, which is essential for structures like the external ear (pinna) and the epiglottis. Elastic cartilage combines support with elasticity, making it distinct from other types of cartilage that focus more on strength or cushioning.

Why Other Options Are Wrong:

hyaline

This is incorrect because hyaline cartilage has a smooth, glassy appearance with few visible fibers. It provides support with some flexibility and is found in the nose, trachea, larynx, and at the ends of long bones.

fibro

This is incorrect because fibrocartilage contains thick bundles of collagen fibers, making it very strong and resistant to compression. It is found in intervertebral discs, pubic symphysis, and menisci, not in the external ear or epiglottis.

reticular

This is incorrect because reticular tissue is a type of connective tissue with reticular fibers forming a soft framework in lymphoid organs like the spleen and lymph nodes. It is not cartilage.

areolar

This is incorrect because areolar tissue is a loose connective tissue that provides cushioning and support under epithelial layers. It does not form cartilage and is unrelated to the ear or epiglottis.

Correct Answer:

tissue

Explanation:

A tissue is a group of similar cells working together to perform a specific function. In the human body, there are four main types of tissues: epithelial (covering and lining surfaces), connective (support and binding), muscle (movement), and nervous (communication). Tissues represent the next organizational level above cells, and they form the foundation for organs, which are made of multiple tissues combined.

Why Other Options Are Wrong:

organ

This is incorrect because an organ is made of multiple tissues working together, not just similar cells. Examples include the heart, lungs, and stomach.

cell

This is incorrect because a cell is the basic unit of life. While cells make up tissues, a single cell by itself is not a tissue.

system

This is incorrect because a system is a higher level of organization, consisting of multiple organs working together to perform a body function, such as the digestive system.

atom

This is incorrect because atoms are the smallest units of matter. They combine to form molecules but do not create tissues or life functions by themselves.

Correct Answer:

reticular layer

Explanation:

The reticular layer is the deeper portion of the dermis. It is composed of dense irregular connective tissue, which provides strength and elasticity to the skin. This layer houses blood vessels, sweat glands, sebaceous glands, hair follicles, and pressure receptors such as Pacinian corpuscles. Its collagen and elastic fibers support skin structure while allowing flexibility. The reticular layer also plays a key role in thermoregulation and sensory reception.

Why Other Options Are Wrong:

papillary layer

This is incorrect because the papillary layer is the upper layer of the dermis. It contains areolar connective tissue, capillaries, and tactile receptors like Meissner’s corpuscles, not the dense irregular connective tissue of the reticular layer.

hypodermis

This is incorrect because the hypodermis (subcutaneous layer) lies beneath the dermis. It consists mainly of adipose and areolar tissue, providing insulation, cushioning, and energy storage, not dense irregular connective tissue.

subcutaneous

This is incorrect because “subcutaneous” is another name for the hypodermis. It is not part of the dermis itself and therefore does not contain the reticular layer’s specialized structures.

Correct Answer:

active transport

Explanation:

Active transport requires energy (usually ATP) to move molecules across the membrane against their concentration gradient, from low concentration to high concentration. This process is critical for maintaining gradients such as sodium-potassium balance in cells. Because molecules move against their natural direction of flow, energy input is essential.

Why Other Options Are Wrong:

passive transport

This is incorrect because passive transport does not require energy. It relies on concentration gradients to move molecules, such as in diffusion and osmosis.

osmosis

This is incorrect because osmosis is the diffusion of water through a selectively permeable membrane, which occurs without energy.

facilitated diffusion

This is incorrect because facilitated diffusion uses carrier proteins or channels but still does not require energy, as molecules move down their concentration gradient.

Correct Answer:

fibrosis

Explanation:

Fibrosis is the repair process in which damaged tissue is replaced with dense connective tissue, forming a scar. While this restores structural integrity and prevents further injury or infection, it does not fully restore the original function of the tissue. Scars are common in tissues that cannot regenerate well, such as cardiac muscle and nervous tissue. Fibrosis is therefore more about strength and closure than restoring normal activity.

Why Other Options Are Wrong:

granulation

This is incorrect because granulation tissue is temporary tissue formed during the early stages of wound healing. It is made of new capillaries, fibroblasts, and inflammatory cells but is later replaced by either regeneration or fibrosis.

regeneration

This is incorrect because regeneration restores damaged tissue with the same type of cells, maintaining both structure and function. Fibrosis, by contrast, leaves scar tissue without full restoration of original function.

inflammation

This is incorrect because inflammation is the initial response to injury, involving redness, swelling, pain, and heat. It helps initiate healing but does not replace tissue or form scars.

Correct Answer:

dorsal

Explanation:

The term dorsal means toward the back or posterior side of the body. In human anatomy, it is often used interchangeably with posterior, although dorsal specifically refers to the back surface. For example, the spine is on the dorsal side of the body. In animals, dorsal refers to the back or upper surface, such as the dorsal fin of a fish. This term is crucial for clear anatomical orientation.

Why Other Options Are Wrong:

proximal

This is incorrect because proximal refers to being closer to the point of origin or attachment, particularly when describing limbs. It does not describe orientation toward the back of the body.

ventral

This is incorrect because ventral means toward the front or belly side of the body. It is the opposite of dorsal, so it cannot describe orientation toward the back.

superficial

This is incorrect because superficial describes a structure closer to the surface of the body. It refers to depth rather than front/back orientation.

medial

This is incorrect because medial means closer to the midline of the body. It describes side-to-side positioning, not orientation toward the back or posterior.

Correct Answer:

ventral

Explanation:

The ventral cavity is the closed anterior body cavity. It lies toward the front of the body and is divided into the thoracic cavity (above the diaphragm) and the abdominopelvic cavity (below the diaphragm). The ventral cavity houses vital organs including the heart, lungs, stomach, intestines, bladder, and reproductive organs. It is lined by serous membranes, which secrete fluid to reduce friction and protect internal organs as they move.

Why Other Options Are Wrong:

dorsal

This is incorrect because the dorsal cavity is the closed posterior body cavity. It includes the cranial and vertebral cavities, housing the brain and spinal cord, not the anterior organs.

vertebral or spinal

This is incorrect because the vertebral cavity is part of the dorsal cavity. It encloses and protects the spinal cord within the vertebral column, but it is not located anteriorly.

cranial

This is incorrect because the cranial cavity is also part of the dorsal cavity, enclosing the brain. It is posterior, not anterior, and therefore does not match the description.

sagittal

This is incorrect because sagittal is not a cavity at all. It is an anatomical plane dividing the body into right and left portions, so it does not describe a closed anterior cavity.

Correct Answer:

nervous

Explanation:

Nervous tissue contains specialized cells called neurons that generate and transmit electrochemical signals. These signals allow rapid communication between different parts of the body and coordination of body functions. Nervous tissue is found in the brain, spinal cord, and nerves. It also includes supporting cells called neuroglia, which protect, nourish, and insulate neurons. This tissue is essential for sensory input, motor output, and integration of information.

Why Other Options Are Wrong:

muscular

This is incorrect because muscular tissue generates force and movement by contracting, not by transmitting electrical signals. While muscles respond to nerve impulses, they do not generate or conduct them like neurons.

connective

This is incorrect because connective tissue provides support, structure, transport, and storage. Examples include bone, cartilage, blood, and adipose tissue. It does not transmit electrochemical signals.

epithelial

This is incorrect because epithelial tissue covers surfaces, lines cavities, and forms glands. It serves as a barrier and is involved in secretion and absorption but does not generate or transmit nerve impulses.

Correct Answer:

blast

Explanation:

In connective tissue terminology, the suffix -blast refers to an immature, active cell that secretes the extracellular matrix. Examples include fibroblasts (which secrete fibers in connective tissue proper), chondroblasts (which produce cartilage matrix), and osteoblasts (which form bone matrix). These cells are metabolically active and essential for tissue growth and repair. Over time, they typically mature into less active -cytes, which maintain the matrix rather than secrete it.

Why Other Options Are Wrong:

chondro

This is incorrect because chondro- is a prefix that means cartilage. It does not by itself mean “immature” or “matrix-secreting.”

cyte

This is incorrect because -cyte refers to a mature cell that maintains tissue rather than secretes matrix. For example, chondrocytes maintain cartilage but do not actively secrete large amounts of new matrix.

fibro

This is incorrect because fibro- is a prefix meaning fiber. It is part of terms like fibroblast (a fiber-forming cell) but does not by itself mean “immature” or “matrix-secreting.”