Lecture 1 Introduction to Human Biology PDF

Wednesday, December 04, 2024 1 It is a Greek term that means “ the science of life” ( = life, = science). It is the natural science that studies life and living organisms from all its aspects. It includes the study of living and non-living parts of life. Studying living organisms is div...

Wednesday, December 04, 2024 1 It is a Greek term that means “ the science of life” ( = life, = science). It is the natural science that studies life and living organisms from all its aspects. It includes the study of living and non-living parts of life. Studying living organisms is divided into specialized fields covering their morphology, physiology, growth, origin, evolution, distribution & taxonomy. It is the study of the anatomy and all human activities such as growth, nutrition, reproduction, respiration, digestion, excretion, secretion etc. Wednesday, December 04, 2024 2 o Organized from the atom to the biosphere. o Consume and transform energy from the environment. o Living organisms regulate its internal environment to maintain a stable and constant condition ( ). o Respond to internal and external stimuli. o Reproduce and grow. o Have an evolutionary history through which organisms change over time. Fundamental axioms of the modern biology: Cells are the basic unit of life. Ø New species and inherited traits are the product of evolution. Ø Genes are the basic unit of heredity. Wednesday, December 04, 2024 3 o The organization of the Human Body begin at the very small and basic and comes together to form the complete body whose different parts work in unison. o The human body is organized at different levels, starting with the and ending with the entire (see figures below). At each higher level of organization, there is a greater degree of complexity. Atoms combine to form Molecules Molecules combine to form Cells Cells combine to form Tissues Tissues combine to form Organs Organs combine to form Organ systems (body system) Organ systems combine to form organism (human body Organism to form Population Population to form Community Community to form Ecosystem Wednesday, December 04, 2024 4 Ecosystem to form Biosphere “The cell is the fundamental unit of life, and that all living things are composed of one or more cells or the secreted products of those cells”. Ø The cell theory dates back to the 17th century with Robert Hooke who worked for the Royal Society in England. He was the first one to discover cells and he analyzed oak tree bark and found that they had little tiny compartments that he coined as a cell, the cell means a small room. Wednesday, December 04, 2024 5 The human body is composed of elements including Carbon, Hydrogen, Nitrogen, Oxygen, Phosphorus and Sulfur. These elements reside in trillions of cells and non-cellular components of the body. Cells: The basic units of structure and function in the human body, as they are in all living things. Each cell carries out life processes that allow the body to survive. Many human cells are specialized in form and function, as shown in the figure below. Each type of cell in the figure plays a specific role. For example, have long projections that help carry electrical messages to other cells. have many mitochondria that provide the energy they need to move the body. Wednesday, December 04, 2024 6 There are five unifying themes: Ø Organization Ø Information Ø Energy and matter Ø Interactions Ø Evolution Wednesday, December 04, 2024 7 Wednesday, December 04, 2024 8 How do we classify Humans? Wednesday, December 04, 2024 9 oCultural heritage or patterns of our behavior passed from one generation to the next. oHighly developed brains. oCompletely upright stance. oCreative language skills. oVaried tool use. oModification of our environment for our purpose which may threaten the biosphere. Wednesday, December 04, 2024 10