CHAPTER 1: AN INTRODUCTION TO THE HUMAN BODY 1) Introduction A. Definitions: 1. Anatomy = The study of the structure (morphology, form) of the body parts a. Histology = the microscopic study of tissues b. Cytology = the microscopic study of cells 2. Physiology = the study of the function of the body parts B. Life processes distinguish living from non-living things: 1. Ten processes: a. Absorption b. Assimilation c. Circulation d. Digestion e. Excretion f. Growth g. Movement h. Reproduction i. Respiration j. Responsiveness 2. Environmental needs: a. Nutrients (food) for energy
b. Oxygen for cellular respiration c. Water for most metabolic reactions d. Heat to maintain 37 C body temp, enzyme action e. Pressure for breathing and filtering blood through kidneys. Atmospheric- breathing Hydrostatic- blood pressure C. Homeostasis: 1. Definition = the tendency of an organism to maintain a stable internal environment 2. All life processes and metabolic reactions work to maintain homeostasis 3. most homeostatic mechanisms are regulated by negative feedback (see example below):
Example = Maintenance of body temperature at 98.6 F/ 37 C. Sweating; Dilation of superficial blood vessels Increase in heart rate Increase in breathing rate Stress: Body temp increase Body temp decrease Normal body temperature 37 o C Body temp increase Stress: body temp decrease Shivering (involuntary contraction of skeletal muscles) Inactivation of sweat glands Constriction of superficial blood vessels
2). Structural levels of organization: A. The atom (C, H, O) is the least complex level; the smallest particle of an element. Atoms combine with another to form B. Molecules (i.e. CO2, H2O); Molecules combine with another to form C. Macromolecules (i.e. carbohydrates, lipids, proteins, nucleic acids); Macromolecules combine to form D. Organelles (i.e. Cell membrane, nucleus, ribosomes); small organs of a cell each with a particular function; Organelles collectively compose E. Cells (i.e. eukaryotic, prokaryotic, animal, plant); Similar cells are arranged into F. Tissues (i.e. epithelial, connective, muscle, nervous); Two or more tissues combine to form G. Organs (i.e. skin, heart, brain); Two or more organs combine to form H. Organ Systems (i.e. integumentary, Cardiovascular); The eleven organ systems collectively form the I. Organism; the most complex level of organization.
3). Organization of the Human Body A. Body cavities Human Body Axial portion Head Neck Trunk Appendicular porton Arms Legs Major Cavities Dorsal cavity Ventral cavity Cranial Vertebral Thoracic Abdominopelvic brain spinal cord lungs skull vertebrae mediastinum heart esophagus trachea thymus Abdominal Pelvic adrenals stomach bladder pancreas liver anus spleen gallbladder internal intestines kidneys repro organs
4). Serous Membranes of the Ventral Body Cavity A. Membrane = a soft, thin, pliable layer of tissue that either: 1. Covers a vital (visceral organ) = VISCERAL MEMBRANE 2. Lines a body cavity = PARIETAL MEMBRANE B. There is a space between a visceral and parietal membrane into which SEROUS FLUID is secreted for lubrication. C. There are specific names for the membranes around the heart, lungs, and abdominal organs: 1. Serous membranes of the HEART: * The membrane on the surface of the heart is called the visceral pericardium. * The membrane that lines the cavity in which the heart is located is called the parietal pericardium. * The space between these two membranes is called the pericardial cavity, and it is filled with serous fluid. 2. Serous Membranes of the LUNGS: * The membrane on the surface of the lung is called the visceral pleura. * The membrane that lines the cavity in which the lungs are located is called the parietal pleura.
* The space between these two membranes is called the pleural cavity, and it is filled with serous fluid. 3. Serous Membranes of the ABDOMINOPELVIC CAVITY: * The membrane on the surface of the liver, stomach, etc. is called the visceral peritoneum. *The membrane that lines the abdominal cavity is called the parietal peritoneum. * The space between these two membranes is called the peritoneal cavity, and it is filled with serous fluid. 5). Organ system overview: System Name Organs in System Function(s) Integumentary Skeletal Muscular Nervous Skin, hair, nails, sweat glands, sebaceous glands Bones, tendons, ligaments, cartilage Skeletal, cardiac, and smooth muscle Brain, spinal cord, nerves Protection, regulation of body temp, synthesis of vitamin D Support, protection, movement, Ca +2 storage, hematopoesis Movement, heat production Coordination of body parts, control
Endocrine Cardiovascular (Circulatory) Lymphatic Urinary Respiratory Digestive Reproductive Endocrine glands that secrete hormones Heart, blood vessels Lymph nodes, thymus, spleen Kidneys, ureters, urinary bladder, urethra Oral cavity, nose, nasal cavity, pharynx, larynx, trachea, bronchial tubes, lungs, alveoli Mouth, pharynx, esophagus, stomach, small and large intestine, salivary glands, pancreas, gallbladder Male: testes, epididymis, vas deferens, prostate, seminal vesicle, bulbourethral gland,urethra, penis, scrotum Female: ovaries, fallopian tubes, uterus, cervix, vagina, labia, clitoris Maintenance of homeostasis Transport of nutrients, wastes, O 2, and CO 2 Fight infection Removal of wastes from blood, maintain blood ph and electrolytes Exchange of gases (O2 and CO2), maintenance of blood ph and electrolytes Breakdown of food into substances that can be absorbed for energy Production, maintenance and transport of gametes (sperm and egg); production of sex hormones
6). Anatomical terminology A. Definition = a language used to describe the relative position of body parts; needed for communication. B. Anatomical Position = standing erect, face forward, palms forward. C. Terms Referring to Direction/ Relative Position 1. Superior = above (closer to head); Inferior = below (farther away from head) 2. Anterior (ventral) = front; Posterior (dorsal) = back. 3. Medial = middle; Lateral = side. 4. Proximal = closer to trunk; Distal = farther from trunk. 5. Superficial (peripheral) = toward the surface; deep = more internal D. Terms Referring to Body Sections (cuts, planes) 1. Sagittal cut (median): divides the body into right and left portions (midsagittal= equal right and left portions) 2. Frontal (coronal) cut: divides the body into anterior and posterior portions 3. Transverse cut (horizontal): divides the body into superior and inferior portions
E. Terms Referring to Cylindrical Parts (cuts) 1. Cross section = across 2. Oblique section = diagonal 3. Longitudinal section = lengthwise F. Abdominal Body Regions (Tic Tac Toe) 1. Epigastric region- upper middle portion 2. Left and right hypochondriac regions- on each side of the epigastric region 3. Umbilical region- middle portion 4. Left and right lumbar regions- on each side of the umbilical region 5. Hypogastric region- lower middle portion 6. Left and right iliac regions- on each side of the hypogastric portion G. Cavities within the head 1. Oral Cavity- contains the teeth and tongue 2. Nasal cavity- located within the nose, divided into right and left portions by the nasal septum; sinuses are connected to this area 3. Orbital cavity- contain the eyes and associated skeletal muscles and nerves 4. Middle ear cavities- contains the middle ear bones