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Plant anatomy or phytotomy is the general term for the study of the internal structure of plants.Originally, it included plant morphology, the description of the physical form and external structure of plants, but since the mid-20th century, plant anatomy has been considered a separate field referring only to internal plant structure.
The epithalamus (pl.: epithalami) is a posterior segment of the diencephalon. [3] The epithalamus includes the habenular nuclei, the stria medullaris, the anterior and posterior paraventricular nuclei, the posterior commissure, and the pineal gland. [2]
They are located on the undersurface of the brain that, as part of the diencephalon, form part of the limbic system. They are located at the ends of the anterior arches of the fornix. [3] They consist of two groups of nuclei, the medial mammillary nuclei and the lateral mammillary nuclei. [4]
The diencephalon is one of the main vesicles of the brain formed during embryogenesis. During the third week of development a neural tube is created from the ectoderm, one of the three primary germ layers. The tube forms three main vesicles during the third week of development: the prosencephalon, the mesencephalon and the rhombencephalon.
The inner surfaces of the lateral and ventral regions of the cerebrum bulge up into the ventricles; these include both the basal nuclei and the various parts of the pallium and may be complex in structure, especially in teleosts. The dorsal surface of the cerebrum is membranous, and does not contain any nervous tissue. [9]
The main tissues that make up an organ tend to have common embryologic origins, such as arising from the same germ layer. Organs exist in most multicellular organisms. In single-celled organisms such as members of the eukaryotes, the functional analogue of an organ is known as an organelle. In plants, there are three main organs. [3]
English: The fine scale structure of a leaf featuring the major tissues; the upper and lower epithelia (and associated cuticles), the palisade and spongy mesophyll and the guard cells of the stoma. Vascular tissue (veins) is not shown. Key plant cell organelles (the cell wall, nucleus, chloroplasts, vacuole and cytoplasm) are also shown.
The midbrain or mesencephalon is the uppermost portion of the brainstem connecting the diencephalon and cerebrum with the pons. [2] It consists of the cerebral peduncles, tegmentum, and tectum. It is functionally associated with vision, hearing, motor control, sleep and wakefulness, arousal , and temperature regulation. [3]