ORGANIZATION OF MULTICELLULAR ORGANISMS

INTRODUCTION

• All organisms are made up of many things ..
• All the parts have many different structures and functions ..
• Simplest level - cell
• The most complex level - individual organism

CELLS

• Basic structural unit of a living thing
• Prokaryotic - are organisms without a cell nucleus or any other membrane-bound organelles
• Eukaryotic ⬇️⬇️⬇️⬇️
• are organisms whose cells are organized into complex structures by internal membranes and a cytoskeleton.

TISSUE

• A group of similar cells that share a function and structure.
• Cells are arranged in one or more layers in epithtial
• But in connective its more like a connected structure.
• They both have a surface with projections of the plasma membrane

ORGANS

• Is a structure made up of two or more tissue types, that performs a specific job
• Muscle tissue help mix the food with gastric juices
• Epithelial tissues secrete acidic fluids that aid in digestion
• Others secrete mucus to protect the stomach from being harmed by these acids, ⬇️⬇️⬇️⬇️
• And blood supplies oxygen to stomach tissues

Organ systems - Is a group of organs that work together to perform a specific function...
Mouth - chews food
Esophagus - carries food to the stomach
Stomach acids - break down foods then is released into the small intestines
Pancreas and Liver - secrete substances into the small intestine to help complete digestion
The digested nutrients and minerals are absorbed into the body
Undigested materials pass into the large intestine, where water is absorbed and bacteria changes some of the waste into vitamins

The organ systems include :
Nervous, immune, muscular, endocrine, skeletal, integumentary, circulatory, respiratory, digestive, urinary, and reproductive.

Same : they all in general have different parts but work together to get the job done
Difference : unicellular only has one cell but still has to do a bunch of things for its job to work out . 🆗

INTERRELATED ORGAN SYSTEMS

• An organ system may be dedicated to a single function or share multiple functions with other systems.
• The respiratory system are to bring oxygen into the body and to remove carbon dioxide made by some cells.
• The circulatory systems transports oxygen, nutrients, carbon dioxide, and metabolic waste throughout the body
• Veins carry blood to the heart and arteries carry blood away from the heart

The circulatory system transports oxygen that maybe the respiratory system brought in. (?)

STRUCTURE AND FUNCTION IN PLANT CELLS