Anatomy Physiology I BIO 1110 Lecture and Lab

Anatomy & Physiology I BIO 1110 - Lecture and Lab Levels of Anatomical Organization and Homeostasis

Levels of Anatomical Organization A. Atoms- The smallest particles of matter that still retain the characteristics of that matter. • 7 atoms essential for maintaining life • Carbon, hydrogen, oxygen, nitrogen, phosphorus, calcium and sulfur B. Molecule- Two or more atoms that are chemically bonded together. • Important molecules to life are DNA, glucose (blood sugar), and water • Can be organic or inorganic • Inorganic= Does not contain carbon (ex. water) • Organic= Carbon containing (ex. glucose)

C. Cell- The basic structural and functional units of the body. D. Tissue- A group of 2 or more cells, all having similar origins and working together to perform a specific function. • 4 types of tissue in the human body • Epithelial= Covers and lines structures and cavities • Nervous= Transmits electrical information • Muscular= Moves the body and generates heat • Connective= Connects, protects and supports body organs E. Organ- A group of tissues working together to perform a specific function • Example= stomach What tissue type(s)?

F. Organ System- A group of organs working together to perform life functions. • Complete the organ systems chart G. Organism- A group of organ systems working together.

Integumentary System

Skeletal System

Muscular System

Nervous System

Endocrine System

Cardiovascular System

Lymphatic/Immune System

Respiratory System

Digestive System

Urinary System

Reproductive System

Homeostasis • The condition of equilibrium under which the body works its best. • Feedback system: A cycle of events in which conditions of the body are monitored, evaluated, changed and reevaluated. – The 3 parts to a feedback system are: • receptor • control center • effector

Draw in your notes… Figure 1. 4

Feedback Loop • Receptors- Specialized cells that monitor conditions inside and outside of the body. – Examples include thermoreceptors (detect temp changes), baroreceptors (detect pressure changes), etc. • Control Center- Receives information from the receptor and compares the information to the ranges set for homeostasis. – Usually the brain • Effectors- Structures that receive information from the control centers and work to change the function of the body.

Negative Feedback • Most common way that homeostasis is maintained in the body • The response of the effector negates or opposes the stimulus (shuts off the original stimulus) • Example- Controlling increased blood pressure by decreasing the heart rate.

Negative Feedback System

Positive Feedback • NOT a way to maintain homeostasis • The response of the effector reinforces or exaggerates the stimulus • Example- Cervix stretching and oxytocin released during childbirth Figure 1– 5

Positive Feedback System
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