Human skeleton in the context of "Human rib cage"

A humanoid (/ˈhjuːmənɔɪd/; from English human and -oid "resembling") is a non-human entity with human form or characteristics. By the 20th century, the term came to describe fossils which were morphologically similar, but not identical, to those of the human skeleton.

Although this usage was common in the sciences for much of the 20th century, it is now considered rare. More generally, the term can refer to anything with distinctly human characteristics or adaptations, such as possessing opposable anterior forelimb-appendages (i.e. thumbs), visible spectrum-binocular vision (i.e. having two eyes), or biomechanic plantigrade-bipedalism (i.e. the ability to walk on heels and metatarsals in an upright position). Humanoids may also include human-animal hybrids (where each cell has partly human and partly animal genetic contents). Science fiction media frequently present sentient extraterrestrial lifeforms as humanoid as a byproduct of convergent evolution.

Comparative anatomy is a study of similarities and differences in the anatomy of different species. It is closely related to evolutionary biology and phylogeny (the evolution of species).

The science began in the classical era, continuing in the early modern period with work by Pierre Belon who noted the similarities of the skeletons of birds and humans.

An exoskeleton (from Ancient Greek έξω (éxō) 'outer' and σκελετός (skeletós) 'skeleton') is a skeleton that is on the exterior of an animal in the form of hardened integument, which both supports the body's shape and protects the internal organs, in contrast to an internal endoskeleton (e.g. that of a human) which is enclosed underneath other soft tissues. Some large, hard and non-flexible protective exoskeletons are known as shell or armour.

Examples of exoskeletons in animals include the cuticle skeletons shared by arthropods (insects, chelicerates, myriapods and crustaceans) and tardigrades, as well as the skeletal cups formed by hardened secretion of stony corals, the test/tunic of sea squirts and sea urchins, and the prominent mollusc shell shared by snails, clams, tusk shells, chitons and nautilus. Some vertebrate animals, such as the turtle, have both an endoskeleton and a protective exoskeleton.

An occupational injury is bodily damage resulting from working. The most common organs involved are the spine, hands, the head, lungs, eyes, skeleton, and skin. Occupational injuries can result from exposure to occupational hazards (physical, chemical, biological, or psychosocial), such as temperature, noise, insect or animal bites, blood-borne pathogens, aerosols, hazardous chemicals, radiation, and occupational burnout.

While many prevention methods are set in place, injuries may still occur due to poor ergonomics, manual handling of heavy loads, misuse or failure of equipment, exposure to general hazards, and inadequate safety training.

The human musculoskeletal system (also known as the human locomotor system, and previously the activity system) is an organ system that gives humans the ability to move using their muscular and skeletal systems. The musculoskeletal system provides form, support, stability, and movement to the body.

The human musculoskeletal system is made up of the bones of the skeleton, muscles, cartilage, tendons, ligaments, joints, and other connective tissue that supports and binds tissues and organs together. The musculoskeletal system's primary functions include supporting the body, allowing motion, and protecting vital organs. The skeletal portion of the system serves as the main storage system for calcium and phosphorus and contains critical components of the hematopoietic system.

Personifications of death are found in many religions and mythologies. In more modern stories, a character known as the Grim Reaper (usually depicted as a berobed skeleton wielding a scythe) causes the victim's death by coming to collect that person's soul. Other beliefs hold that the spectre of death is only a psychopomp, a benevolent figure who serves to gently sever the last ties between the soul and the body, and to guide the deceased to the afterlife, without having any control over when or how the victim dies. Death is most often personified in male form, although in certain cultures death is perceived as female (for instance, Marzanna in Slavic mythology, or Santa Muerte in Mexico). Death is also portrayed as one of the Four Horsemen of the Apocalypse. Most claims of its appearance occur in states of near-death.

Human body shape is a complex phenomenon with sophisticated detail and function. The general shape or figure of a person is defined mainly by the molding of skeletal structures, as well as the distribution of muscles and fat. Skeletal structure grows and changes only up to the point at which a human reaches adulthood and remains essentially the same for the rest of their life. Growth is usually completed between the ages of 13 and 18, at which time the epiphyseal plates of long bones close, allowing no further growth (see Human skeleton).

Many aspects of body shape vary with gender and the female body shape especially has a complicated cultural history. The science of measuring and assessing body shape is called anthropometry.

The axial skeleton is the core part of the endoskeleton made of the bones of the head and trunk of vertebrates. In the human skeleton, it consists of 80 bones and is composed of the skull (28 bones, including the cranium, mandible and the middle ear ossicles), the vertebral column (26 bones, including vertebrae, sacrum and coccyx), the rib cage (25 bones, including ribs and sternum), and the hyoid bone. The axial skeleton is joined to the appendicular skeleton (which support the limbs) via the shoulder girdles and the pelvis.

The rib cage or thoracic cage is an endoskeletal enclosure in the thorax of most vertebrates that comprises the ribs, vertebral column and sternum, which protect the vital organs of the thoracic cavity, such as the heart, lungs and great vessels and support the shoulder girdle to form the core part of the axial skeleton.

A typical human thoracic cage consists of 12 pairs of ribs and the adjoining costal cartilages, the sternum (along with the manubrium and xiphoid process), and the 12 thoracic vertebrae articulating with the ribs. The thoracic cage also provides attachments for extrinsic skeletal muscles of the neck, upper limbs, upper abdomen and back, and together with the overlying skin and associated fascia and muscles, makes up the thoracic wall.