Answer
The primary embryonic germ layers are - from outer to inner layer - ectoderm, mesoderm (middle) and
endoderm.
The ectoderm is the outer layer that gives rise to the epidermis, and the nervous system.
Mesenchyme (a gelatinous tissue) derives from the mesoderm. Mesenchyme gives rise to muscles,
bones, and blood.
The mucus membrane of the digestive tract and the respiratory tract develop from endoderm.
Digestive glands are also of enpidermal origin
Work Step by Step
Addendum to 5.1:4
The matrix is an important component of tissues. It is an extracellular, non living material that consists of fibers and ground substance. Ground substance may be solid, gelatinous or fluid. It supplies water, nutrients, and oxygen to cells; it also receives and removes metabolic wastes, Co2 , hormones, and other dissolved substances from cells. In bones, the ground substance is hard and rigid ; its functions are support, protection, and service as mechanical levers in muscular movements.
