Skeleton - Bones, Joints, Muscles | Britannica
WEBSep 5, 2024 · Skeleton - Bones, Joints, Muscles: In vertebrates the adult skeleton is usually formed of bone or cartilage—living substances that grow with the animal, in contrast to the many types of invertebrate skeleton that do not grow or are dead secretions, deposits, or …
Human digestive system | Description, Parts, & Functions
WEBSep 14, 2024 · human digestive system, system used in the human body for the process of digestion.The human digestive system consists primarily of the digestive tract, or the series of structures and organs through which food and liquids pass during their processing into forms that can be absorbed into the bloodstream. The system also consists of the …
Vertebral column | Anatomy & Function | Britannica
WEBSep 13, 2024 · Vertebrae in lower vertebrates are more complex, and the relationships of their parts to those of higher animals are often unclear. In primitive chordates (e.g., amphioxus, lampreys) a rodlike structure, the notochord, stiffens the body and helps protect the overlying spinal cord.
Human skeleton - Arms, Legs, Joints | Britannica
WEBSep 14, 2024 · Human skeleton - Arms, Legs, Joints: The humerus and the femur are corresponding bones of the arms and legs, respectively. While their parts are similar in general, their structure has been adapted to differing functions.
Human skeleton - Hands, Feet, Joints | Britannica
WEBSep 14, 2024 · Human skeleton - Hands, Feet, Joints: The skeleton of the wrist, or carpus, consists of eight small carpal bones, which are arranged in two rows of four each. The skeleton of the ankle, or tarsus, has seven bones, but, because of the angle of the foot to the leg and the weight-bearing function, they are arranged in a more complicated way.
skeleton - Students | Britannica Kids | Homework Help
WEBThe human skeleton is divided into two main parts—the axial skeleton and appendicular skeleton. The axial skeleton consists of the head, neck, and trunk. The appendicular skeleton is made up of the arms and legs.
Skull | Definition, Anatomy, & Function | Britannica
WEBSkull, skeletal framework of the head of vertebrates, composed of bones or cartilage, which form a unit that protects the brain and some sense organs. The skull includes the upper jaw and the cranium. Learn more about the anatomy and function of the skull in humans and other vertebrates.
Human skeleton - Mandible, Muscles, Joints | Britannica
WEBSep 14, 2024 · Human skeleton - Mandible, Muscles, Joints: The left and right halves of the lower jaw, or mandible, begin originally as two distinct bones, but in the second year of life the two bones fuse at the midline to form one. The horizontal central part on each side is the body of the mandible.
Hand | Definition, Anatomy, Bones, Diagram, & Facts | Britannica
WEBSep 1, 2024 · knuckle. finger. finger flexor tendon. hand, grasping organ at the end of the forelimb of certain vertebrates that exhibits great mobility and flexibility in the digits and in the whole organ. It is made up of the wrist joint, the carpal bones, the metacarpal bones, and the phalanges. The digits include a medial thumb (when viewed with the palm ...
Echinoderm - Radial Symmetry, Tube Feet, Spines | Britannica
WEB6 days ago · Skeleton. The skeleton is dermal but nonetheless conspicuous in echinoderms, with the exception of most holothurians, and forms an effective armour. Each skeletal unit (ossicle) usually consists of two parts, a living tissue (stroma) and a complex lattice (stereom) of mineral calcium carbonate, or calcite, which is derived from the …