chapter # 31 animal systems and homeostasis structure and function pg. 636 - 644
Post on 20-Dec-2015
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TRANSCRIPT
• Cells are organized into tissues.
• Tissues are organized into organs.
• Organs are organized into systems.
• Systems form an organism.
Organization in Living Things
Epithelial Tissue
• Epithelial cells form the outer covering, line the internal cavities, and make up the glands.
• Examples: Skin, mucous membranes.
Connective Tissue• Consists of
living cells in a secreted matrix.
• Examples: bone, cartilage, blood.
Muscular Tissue• Specialized
protein fibers allow these cells to contract.
• Examples: skeletal muscle, smooth muscle, cardiac muscle.
Nervous Tissue• Neurons have
the ability to pass an “electrical” signal from one cell to another, or to target cells (muscles, glands, organs).
Tissues Form Organs
• The skin is an example of an organ made up of multiple tissues: epithelial, muscular, nervous, and connective tissues.
Organs To Organ Systems
•Nervous System
•Endocrine System
•Musculo-skeletal System
•Circulatory System
•Respiratory System
•Digestive System
•Immune System
Homeostasis• Homeostasis is the act of keeping
the internal environment of a living organism within an acceptable range of conditions.
• Homeostasis controls temperature, pH, blood volume, oxygen levels, blood sugar levels, and other conditions.
• Negative feedback maintains homeostasis.
Negative Feedback• Negative feedback
keeps conditions within an ideal range.
• As conditions exceed the limits of the ideal range, chemical signals (hormones) regulate conditions. Most often this is controlled by the hypothalamus in the brain.
Positive Feedback• Positive feedback
takes a condition out of the normal range, often to some end point.
• During labor, oxytocin increases contractions, which stimulate more oxytocin production, until birth occurs.