Introduction to Anatomy & Physiology Fall 2011 Chapter 1 Week 1
What is… • Anatomy • Physiology
Summary • Discussion of the necessary life functions and how each organ system plays several functions to support the living organism • Discuss homeostasis and the diseases state that develops when homeostatic mechanisms are out of balance • Discuss anatomical landmarks, divide the body into sections and planes and be able to identify the body cavities and their components
Anatomy vs Physiology • Anatomy- study of the structure of the human body and the relationship of its parts • Anatomy is derived from the Greek words meaning to cut (tomy) apart (ana) • Physiology- study of body functions; how the parts work • How then are Anatomy and Physiology related?
Structure and Function Anatomy and physiology are therefore separate but, since function always reflects structure they are inseparable. This is called the principle of complimentarity of structure and function
Structure Determines Functions • The heart is a muscular chamber and is able to pump the blood • Blood flows in one direction do to valves located in the vessels • The lungs cannot pump blood because the walls of its air sacs are very thin But the exchange of gases and the bodies oxygen supply occur in the lungs
Maintaining Life • Maintain boundaries • Move • Respond to environmental changes • Take in and digest nutrients • Metabolism • Dispose of waste • Reproduce • Grow
Survival Needs Organisms Survival Depends on Body Temperature Atmospheric Pressure Oxygen Water Nutrients
Why though? • Why does the body need all that stuff and go through all the trouble it does? GOAL??????
Homeostasis Literal translation is “unchanging” Coined by Walter Cannon “wisdom of the body” • The body is in a constant state of flux, balancing between a range of normal values that is never static
Homeostatic Control Mechanisms • Communication - nervous and endocrine systems • Factor: Variable • All homeostatic control mechanisms contain • Receptor • Control center • Effector
Homeostatic Control Mechanisms Nervous and Endocrine Systems 3 Components Receptor Control Effector
Depressing the response or negative feedback Negative Feedback: Control mechanism is shut off Net effect of the response is to shut off the original stimulus or greatly reduce it Control of blood glucose levels by pancreatic hormones Enhancing the response or positive feedback: Cascades Rare Blood clotting and birth of a baby Feedback
Anatomical Position • Necessary to standardize and simplify the study of anatomy • Anatomical position: • Standing, • Facing the observer • Palms facing forward • Toes pointed toward the observer • Always reference the left or right of the body as you view it
Two Body Cavities(*anatomical position*) A. Ventral cavity: 1. Thoracic cavity- Right & Left Pleural Cavity, Mediastinum (inside is Pericardial Cavity) Diaphragm muscle- separates cavities 2. Abdominopelvic cavity- Abdominal cavity, Pelvic cavity
Two Body Cavities (*anatomical position*) B. Dorsal cavity: • Cranial cavity- skull & brain • Spinal cavity- vertebral column & spinal cord
Other Body Cavities • Oral and digestive cavities • Nasal cavity • Orbital cavities • Middle ear cavities • Synovial cavities
Regional Terms • Axial: Head, neck and trunk • Appendicular: Appendages
Anatomical Position • Anatomical terminology can be divided into 2 types: • components of the body • terms that refer to direction, eg, proximal or distal.
VI. Serous Membranes: Serosa: double layered membrane that covers the walls and outer surfaces of the organs • Parietal- surrounding wall of body cavity • Visceral- inside membrane that covers organs
Directional Relationships • Anterior ( Ventral): toward the front of the body • Posterior (Dorsal): toward the back of the body • Superior (Cranial or cephalad): above; toward the head • Inferior ( caudal): below; toward the feet • Medial: toward the midline; toward the mid-saggital • Lateral: away from the midline
Directional Terms • Proximal: toward the body or root • Distal: away from the body or root • Superficial: toward the surface • Deep: away from the surface • Intermediate: between a more medial and a more lateral structure
The wrist is ________ to the hand • The breastbone is ________ to the spine • The brain is _______ to the spinal cord • The lungs are ________to the stomach • The thumb is __________ to the fingers.
Review: ALL descriptions of the human body and movement start in anatomical position.
Planes • Sagittal- cut in right & left halves; midsagittal is exactly on midline • Coronal/Frontal- cut lengthwise or vertically; cut into anterior & posterior halves • Transverse/Horizontal- crosswise, superior & inferior halves Oblique- cutting at a diagonal
Body Types: Somatotype- body build or physique; determined by gender, exercise, diet, & heredity • Endomorph- • large waistline or “apple-shaped” – risky health • small waistline or “pear-shaped” –not as risky. • Mesomorph – medium waistline; medium build • Ectomorph – skinny waistline; skinny build