Human Biology – Applicable to Your LIFE!!!

What is Life Anyway?  What does it mean to you to be alive?  From a biological perspective, what must you be able to do to be considered living?

The Unity of Life – Starts w/DNA (Section 1.4) Living Things... Are highly ordered Are made up molecules Contain DNA Are composed of cells Can utilize energy Regulate their environment Respond and adapt to their environment Grow and Develop Reproduce Evolves or changes over time

The Hierarchy of Life – Levels of Organization  1. Chemicals  Atoms & Molecules  2. Cells  Composed of chemicals and organelles  3. Tissues  Epithelial, connective, muscle, nervous  5. Organs  Two or more tissues working together  6. Organ systems  11 systems total  7. Organism

So, where do anatomy & physiology come in...  Anatomy – Structure of the body  1. Systemic – approach in this textbook  2. Regional – approach for medical/dental school  3. Surface – approach used to diagnose disease  Anatomical Imaging  Physiology –Function of the body  Understand and predict the body’s response to stimuli  Understand how body maintains homeostasis  What is Homeostasis?

11 major organ systems  1. Integumentary  2. Skeletal  3. Muscular  4. Nervous  5. Endocrine  6. Cardiovascular  7. Lymphatic  8. Respiratory  9. Digestive  10. Urinary  11. Reproductive

homeostasis  Homeostasis – existence and maintenance of a relatively constant environment within the body – a dynamic equilibrium  1. Negative feedback – maintain homeostasis – any deviation from a normal value is diminished or resisted  2. Positive feedback – not homeostatic and are rare in healthy humans – when a deviation from the norm occurs, it is increased by positive feedback. One of the few examples of a normally occurring positive feedback mechanism is the birth process

Terminology and the body plan  All directional terms apply to anatomical position  Etymology – Word Origin (mostly Latin and Greek)  Superior/Inferior – above/below  Anterior/ventral – in front of  Posterior/dorsal - behind  Proximal/Distal – closer to the center/further from center  Lateral/Medial – to the side/to the center  Superficial/Deep – on the surface/deep TABLE 1.1 – Page 10

planes FOR THE BODY  Sagittal – vertical plane  Midsagittal – in the middle to divide rt/lt  Transverse/horizontal  Frontal/coronal – vertical, but ant/post. FOR ORGANS  Longitudinal – vertical  Transverse/cross –  Oblique – comes down at an angle

Body regions  Upper limb  Arm – shoulder to elbow  Forearm – elbow to wrist  Lower limb  Thigh – hip to knee  Leg – knee to ankle  Central region  Head, neck, trunk  Trunk – further subdivided into >Thorax, abdomen, pelvis

Body cavities  3 major trunk cavities  1. Thoracic cavity – surrounded by rib cage, bounded by diaphragm, separated into right and left parts by a mediastinum  What is the Mediastinum? Name for the compartment that divides the thoracic cavity (with the lungs on either side) and structure that contains the heart, thymus gland, tracheal, esophagus, etc

Body cavities, continued  2. Abdominal cavity – bounded by the abdominal muscles and contains the stomach, intestines, liver, spleen, pancreas, and kidneys  3. Pelvic cavity – enclosed by the bones of the pelvis – contains urinary bladder, part of the large intestine, internal reproductive organs  The abdominal and pelvic cavities are not physically separated and are sometimes called the abdominopelvic cavity

Serous membranes  Serous membranes line the trunk cavities and cover the organs of the trunk cavities  These double-walled membranes contain:  1. Visceral membrane  2. Cavity  3. Parietal membrane

Locations of serous membranes  Thoracic cavity  1. Pericardial cavity and membranes  2. Left and right pleural cavities and membranes  Abdominopelvic cavity  1. Peritoneal cavity and membrane  Mesentery  Retroperitoneal organs

Peritoneum w/microvilli