The protrusion of the cell surface is an initial step for several cellular processes, including cell migration, phagocytosis, and neurite outgrowth. These membrane protrusions are a result of cytoskeletal rearrangement. The most  widely observed cell protrusions include lamellipodia, pseudopodia, filopodia, microvilli, invadopodia, and podosomes. These protrusions can be of two types — static or dynamic.
The microvilli, an example of stable protrusions, are finger-like projections with a...

Bones have various surface features that help form joints and attach to other soft tissues. Depending on the function, bone markings are categorized into articulating projections, processes for attachment, depressions, and openings.
Articulating Projections
Articulating projections are found where two bones meet to form a joint. These structures are usually found at the ends of bones. The largest articulation is a rounded projection called the head, supported by a narrow neck at the ends of...

There are hollow fluid-filled cavities known as ventricles deep inside the human brain. There are two lateral ventricles, one in each cerebral hemisphere, and each has three different projections — the anterior, inferior, and posterior horns visible from the lateral side. A thin membrane called the septum pellucidum separates the two lateral ventricles. The slender third ventricle in the diencephalon is connected to each lateral ventricle via a channel called the interventricular foramen. The...

In analyzing a thin-walled hollow shaft subjected to torsional loading, a segment with width dx is isolated for examination. Despite its equilibrium state, this segment faces torsional shearing forces at its ends. These forces are quantitatively described by the product of the longitudinal shearing stress on the segment's minor surface and the area of this surface, leading to the concept of shear flow. This shear flow is consistent throughout the structure, indicating a uniform distribution of...

The respiratory zone of the human body, which stands in contrast to the conducting zone, comprises the structures that actively participate in the exchange of gases. The initiation of this zone is marked by the terminal bronchioles converging into respiratory bronchioles, the tiniest bronchiole classification. The respiratory bronchioles give way to the alveolar ducts that opens into a congregation of alveoli. Actively involved in gas exchange, alveoli resemble tiny sacs similar to clusters of...

Cavity walls feature a hollow space between the outer and inner wythes, connected only by corrosion-resistant metal ties. When water seeps through the outer wythe, it descends within this cavity, intercepted by flashing and eventually exiting through weep holes. To enhance moisture resistance, the inner wythe's cavity side often receives damp-proofing, doubling as an air barrier. The cavity can also house insulation to mitigate heat transfer.
Maintaining a clean cavity during construction is...