Chapter 1 ORGANIZATION ANDGENERAL PLAN OF THE BODY OVERVIEW AND TERMINOLOGY
Summary Definitions Organization of the human body Metabolism and Homeostasis Negative feedback Positive feedback Anatomical position and descriptive terms Body cavities Planes and sections
Definitions Physiology – Anatomy – ***These 2 are intimately linked – structures designed for particular functions.?Pathophysiology-
Organization of the Human Body Chemicals combine to form… Cells, similar cells combine to form… Tissues, two or more tissues combine to form an… Organ, two or more work together as an… Organ system, all organ systems work together to support the… Organism
Chemicals Simplest chemical is an element, 20 are found in the human body. Each element is composed of unique atoms. Atoms combine to form molecules and compounds: Inorganic – Organic –
Chemicals Molecules & compounds combine to form macromolecules. Organic macromolecules in living organisms:
Cells Smallest living structural and functional units. Composed of organic macromolecules.
Tissues Groups of cells with similar structure and function. 4 basic groups: Epithelial tissue – Connective tissue – Muscle tissue - Nerve tissue –
Organs 2 or more tissues that combine to form a structure that performs a particular function. Examples - Heart Lungs ????
Organ System Group of organs that all contribute to a certain body function. Cardiovascular system ????? 11 organ systems: study Table 1-1, p.7 and Figure 1-2, pp. 8-9.
Organ Systems Integumentary system: skin; protects us from chemicals, sun, and pathogens. Skeletal system: bones and ligaments; protects internal organs, provides framework for muscles, supports the body. Muscular system: muscles and tendons; moves the skeleton, produces heat, moves blood and food.
Organ Systems Nervous system: brain, spinal cord, peripheral nerves, sensory organs; collects and interprets sensory information, regulates body functions. Endocrine system: glands, produce hormones that regulate body functions.
Organ systems Circulatory system: heart, blood vessels and blood; transports oxygen and nutrients to tissues. Lymphatic system: lymph glands and vessels; destroys pathogens and returns tissue fluid to circulatory system.
Organ Systems Respiratory system: lungs, trachea, etc.; exchanges O2 and CO2 between the body and the atmosphere. Digestive system: stomach, intestines, liver, etc.; breaks down food into nutrients and absorbs them into the blood stream.
Organ Systems Urinary System: kidneys, urinary bladder, urethra; removes waste products from the blood. Reproductive system: ovaries, testes, uterus, prostate gland; produces eggs or sperm, female provides site for developing offspring.
MetabolismSum of all chemical reactions and processes in the body. Anabolism – Catabolism –Causes changes internally and externally. Ex. Digestion can cause an increase in blood glucose, etc.
Homeostasis A state of relative stability within the body despite changes in the external and internal environment. Maintenance Mechanisms: Negative feedback – blood sugar and temperature regulation. Positive feedback – fever, blood clotting and labor.
Negative FeedbackSequence: Stimulus is “sensed” by a receptor Receptor relays information to a control center Control center evaluates and creates a plan of action Plan sent to effector Effector eliminates the stimulus (corrects problems)
Positive Feedback Sequence Same as for negative feedback except effector does NOT eliminate the stimulus, it increases it. Requires an external “brake”.
Anatomical Position andDescriptive Terms Anatomical position: standing upright, facing forward, arms at the sides palms facing forward, feet slightly apart. Table 1-2 Descriptive Terms and Table 1-3 Terms of Location and Position ***Know these terms and how to use them for the quiz and test 1.
Body Cavities and Membranes 2 major body cavities Dorsal (posterior) cavity – 2 sections Cranial – Vertebral or spinal – The two sections are continuous and lined by membranes called meninges.
Body Cavities and Membranes 2 body cavities cont’d Ventral (anterior) Cavity – two major compartments separated by the diaphragm. Thoracic cavity – Abdominal cavity Pelvic cavity
Body Cavities and Membranes 2 body cavities cont’d Ventral (anterior) Cavity Membranes Thoracic cavity: Parietal pleura lines the chest wall, visceral pleura covers the lungs Visceral pericardium covers the heart and the parietal pericardium lines the sac around the heart.
Body Cavities and Membranes 2 body cavities cont’d Ventral (anterior) Cavity Membranes Abdominal cavity: The peritoneum is a membrane the lines the abdominal wall and continues into the ... The mesentery covers the outer surfaces of the abdominal organs.
Planes and Sections Use: to describe internal anatomy, orientation points, increase visibility. Plane: an imaginary flat surface that separates two portions of the body, fig 1-6.
Planes and Sections Sections: cuts in a body or organ or plane that make the structures more easily visible. Frontal or coronal section – separates the body into front and back sections. Sagittal section – separates the body into right and left portions. Transverse section – separates the body into upper and lower sections.
Planes and Sectionso Other terms that usually refer to organs: o Cross section o Longitudinal section
Areas of the Abdomen Division into 4 quadrants, fig 1-7 RUQ LUQ RLQ LLQ
Areas of the Abdomen 9 regions, fig 1-7 Upper areas: left hypochondriac, epigastric, right hypochondriac. Middle areas: left lumbar, umbilical, right lumbar. Lower areas: left iliac, hypogastric, right iliac.