Chapter 1: Organization of the Human Body

Overview

Studies of the Human Body Anatomy Study of body structure Dissection Physiology Study of body function

Studies of the Human Body Levels of Organization Chemicals Cells Tissues Organs Systems Organism

Studies of the Human Body Body Systems (organized by function) Protection, support, and movement Integumentary Skeletal Muscular Coordination and control Nervous Endocrine

Studies of the Human Body Body Systems (organized by function) Circulation and immunity Cardiovascular Lymphatic Energy supply and fluid balance Respiratory Digestive Urinary Production of offspring Reproductive

Metabolism and Its Regulation Types of Metabolism Catabolism Reactions that break substances down into simpler compounds Used to form ATP Anabolism Reactions that build substances up Simple compounds are used to manufacture materials needed for growth, function and tissue repair Often require ATP-energy obtained from the breakdown of nutrients used to form a compound often described as the cells energy current

Metabolism and Its Regulation Homeostasis Body’s maintenance of internal balance Body fluid balance is especially important Extracellular fluid Blood plasma Lymph Fluid between cells Intracellular fluid Fluid within cells

Metabolism and Its Regulation Homeostasis Negative feedback Critical for maintaining our health Keeps body conditions within a normal range by reversing any upward or downward shift

Figure 1-3 Negative feedback. How does a thermostat respond to a room temperature that falls below normal?

Figure 1-5 Negative feedback in the endocrine system. What happens to insulin levels after a meal?

Metabolism and Its Regulation Effects of Aging Gradual changes in all body systems Some changes are harmless. Wrinkles and gray hair Some changes may result in injury and disease. Decreased kidney function Loss of bone mass Formation of deposits within blood vessels

Body Directions Directional Terms Healthcare professionals use standardized terms to describe body directions. Superior and inferior Anterior (ventral) and posterior (dorsal) Medial and lateral Proximal and distal All descriptions assume that the body is in anatomic position.

Figure 1-6 Directional terms. What is the scientific name for the position in which the figures are standing?

Body Directions Planes of Division Anatomists can divide the body along three planes, each of which is a cut through the body in a different direction Frontal plane AKA “coronal plane” Sagittal plane Transverse plane Superior/inferior

Figure 1-7 Planes of division. Which plane divides the body into superior and inferior parts? Which plane divides the body into anterior and posterior parts?

Body Directions Planes of Division Some additional terms are used to describe tissues and CT or MRI images. Cross section Longitudinal section Oblique section

Figure 1-8 Tissue sections. Which section would cut a blood vessel in half along its long axis?

Body Cavities The body is divided into two main cavities. Dorsal Cavity Two main subdivisions Cranial cavity Spinal cavity Ventral Cavity Two main subdivisions separated by diaphragm (muscle used in breathing) Thoracic cavity Abdominopelvic cavity

Figure 1-10 Body cavities, lateral view. Replace with Fig 1-10 Which cavity contains the diaphragm?

Body Cavities Thoracic Cavity Further subdivided Pericardial cavity Pleural cavity Mediastinum

Figure 1-11 The thoracic cavity. Which cavity contains the lung?

Body Cavities Abdominopelvic Cavity Further subdivided Abdominal cavity Contains the stomach, most of the intestine, liver, gallbladder, pancreas and spleen Pelvic cavity Inferior portion

Body Cavities Divisions of the Abdomen The abdomen can be divided into nine regions. Epigastric Umbilical Hypogastric Hypochondriac (left and right) Lumbar (left and right) Iliac, or inguinal (left and right) Named for the upper crest of the hip bone and groin region

Figure 1-12 The nine regions of the abdomen. Which region contains the spleen?

Body Cavities Divisions of the Abdomen The abdomen can be divided into four quadrants. Right upper quadrant Left upper quadrant Right lower quadrant Left lower quadrant

Figure 1-13 Quadrants of the abdomen. In which region is pain from appendicitis most likely to be felt?

Figure 1-14 Adjectives for some anterior body regions. Where would a pedal pulse be felt?

Figure 1-15 Adjectives for some posterior body regions. Where would cervical pain be felt?

Word Anatomy Word Part Meaning Example -tomy cutting, incision of -dis apart, away from Dissect physi/o nature, physical Physiology -logy study of Radiology cata- down Catabolism ana- upward, again, back Anabolism home/o same Homeostasis stat, -stasis stand, stoppage, constancy extra- outside of, beyond Extracellular intra- within Intracellular