8/27/2017. The Human Body: An Orientation. Homeostasis BODY SYSTEMS WORK TOGETHER TO MAINTIN HOMEOSTASIS. Chapter 1 Part B

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1 Chapter Part B The Human Body: An Orientation Homeostasis The organism s ability to maintain a relatively stable internal conditions even though the outside world is constantly changing. Dynamic State of Equilibrium Consorted Effort Among the Systems Annie Leibovitz/Contact Press Images PowerPoint Lecture Slides prepared by Karen Dunbar Kareiva Ivy Tech Community College Hair Skin Nails BODY SYSTEMS WORK TOGETHER TO MAINTIN HOMEOSTASIS Integumentary System Forms the external body covering, and protects deeper tissues from injury. Synthesizes vitamin D, and houses cutaneous (pain, pressure, etc.) receptors and sweat and oil glands. Skeletal muscles Bones Joint Skeletal System Protects and supports body organs, and provides a framework the muscles use to cause movement. Blood cells are formed within bones. Muscular System Allows manipulation of the environment, locomotion, and facial expression. Maintains posture, and heat.

2 Brain Thyroid gland Thymus Pineal gland Pituitary gland Adrenal gland Pancreas Testis Spinal cord Nerves Ovary Nervous System As the fast-acting control system of the body, it responds to internal and external changes by activating appropriate muscles and glands. Endocrine System Glands secrete hormones that regulate processes such as growth, reproduction, and nutrient use (metabolism) by body cells. Heart Red bone marrow Thymus Lymphatic vessels Thoracic duct Spleen Blood vessels Lymph nodes Cardiovascular System Blood vessels transport blood, which carries oxygen, carbon dioxide, nutrients, wastes, etc. The heart pumps blood. Lymphatic System/Immunity Picks up fluid leaked from blood vessels and returns it to blood. Disposes of debris in the lymphatic stream. Houses white blood cells (lymphocytes) involved in immunity. Nasal Pharynx Larynx Trachea Bronchus Oral Esophagus Lung Liver Stomach Small intestine Large intestine Rectum Anus Respiratory System Keeps blood constantly supplied with oxygen and removes carbon dioxide. Digestive System Breaks down food into absorbable units that enter the blood for distribution to body cells. 2

3 Kidney Ureter Urinary bladder Urethra Penis Prostate Testis Ductus deferens Scrotum Urinary System Eliminates nitrogenous wastes from the body. Regulates water, electrolyte, and acid-base balance of the blood. Male Reproductive System Overall function is production of offspring. Testes produce sperm and male sex hormone, and male ducts and glands aid in delivery of sperm to the female reproductive tract. Mammary glands (in breasts) Homeostatic Control: Negative Feedback Mechanisms Uterus Vagina Ovary Uterine tube The final goal is to shut off the original effect (stress) of the stimulus or reduce its intensity. Attempt to Return to Dynamic Equilibrium. Female Reproductive System Ovaries produce eggs and female sex hormones. The remaining female structures serve as sites for fertilization and development of the fetus. Mammary glands of female breasts produce milk to nourish the newborn. How do negative feedback mechanisms work? Slide 2 Figure.4 Interactions among the elements of a homeostatic control system maintain stable internal conditions. Slide 3 2 Receptor detects change. Receptor 3

4 Figure.4 Interactions among the elements of a homeostatic control system maintain stable internal conditions. 2 Receptor detects change. 3 Input: Information sent along afferent to control center. Receptor Afferent Control Center Slide 4 Figure.4 Interactions among the elements of a homeostatic control system maintain stable internal conditions. 2 Receptor detects change. 3 Input: Information sent along afferent to control center. Control Center 4 Output: Information sent along efferent to effector. Receptor Afferent Efferent Effector Slide 5 Figure.4 Interactions among the elements of a homeostatic control system maintain stable internal conditions. 2 Receptor detects change. 3 Input: Information 4 Output: Information sent along afferent to control center. Control Center sent along efferent to effector. Receptor Afferent Efferent Effector Slide 6 5 Response of effector feeds back to reduce the effect of stimulus and returns variable to homeostatic level. Figure.5 Body temperature Control Center is regulated by a (thermoregulatory center in brain) negative feedback mechanism. Afferent Efferent Receptors Temperature-sensitive Effectors cells in skin and brain Sweat glands Sweat glands activated Response Evaporation of sweat Body temperature Body temperature falls; rises stimulus ends : Heat : Cold Response Body temperature rises; Body temperature stimulus ends falls Effectors Skeletal muscles Receptors Temperature-sensitive cells in skin and brain Shivering begins Efferent Afferent Control Center (thermoregulatory center in brain) Homeostatic Control: Positive Feedback Mechanisms Figure.6 A positive feedback mechanism Break or tear Slide The response enhance the original stimulus so that response is accelerated. Have an amplifying or waterfall effect. 3 Released chemicals attract more platelets. Positive feedback loop 2 Platelets adhere to site and release chemicals. Feedback cycle ends when plug is formed. 4 Platelet plug is fully formed. 4

5 Figure.6 A positive feedback mechanism Break or tear Slide 2 Figure.6 A positive feedback mechanism Break or tear Slide 3 2 Platelets adhere to site and release chemicals. Figure.6 A positive feedback mechanism Break or tear Slide 4 Figure.6 A positive feedback mechanism Break or tear Slide 5 3 Released chemicals attract more platelets. Positive feedback loop 2 Platelets adhere to site and release chemicals. 3 Released chemicals attract more platelets. Positive feedback loop 2 Platelets adhere to site and release chemicals. Feedback cycle ends when plug is formed. 4 Platelet plug is fully formed. Homeostatic imbalance Diseases cause homeostatic imbalance. Age is a contributor to homeostatic imbalance. Collapse of homeostasis leads to system failures. Anatomical Position and Directional Terms 5

6 .5 Anatomical and Directional Terms.5 Anatomical Terms Standard anatomical position Body erect, feet slightly apart, palms facing forward with thumbs pointing away from body d30c6876.png?w=540 Directional terms describe one body structure in relation to another body structure Direction is always based on standard anatomical position and left refer to the body being viewed, not right and left of observer Regional Terms Regional terms designate specific areas within body divisions Two major divisions of body Axial Head, neck, and trunk Appendicular Limbs (legs and arms) Figure.7a Regional terms used to designate specific body areas. Cephalic Frontal Orbital Nasal Oral Mental Cervical Thoracic Sternal Axillary Mammary Abdominal Umbilical Pelvic Inguinal (groin) Pubic (genital) Thorax Abdomen Anterior/Ventral Upper limb Acromial Brachial (arm) Antecubital Antebrachial (forearm) Carpal (wrist) Manus (hand) Palmar Pollex Digital Lower limb Coxal (hip) Femoral (thigh) Patellar Crural (leg) Fibular or peroneal Pedal (foot) Tarsal (ankle) Metatarsal Digital Hallux Figure.7b Regional terms used to designate specific body areas. Upper limb Acromial Brachial (arm) Olecranal Antebrachial (forearm) Cephalic Otic Occipital (back of head) Cervical Back (dorsal) Scapular Table.- Orientation and Directional Terms Manus (hand) Metacarpal Digital Lower limb Femoral (thigh) Popliteal Lumbar Sacral Gluteal Perineal (between anus and external genitalia) Sural (calf) Fibular or peroneal Pedal (foot) Calcaneal Plantar Back (Dorsum) Posterior/Dorsal 6

7 Table.-2 Orientation and Directional Terms (continued) Table.-3 Orientation and Directional Terms (continued) Figure.8 Planes of the body with corresponding magnetic resonance imaging (MRI) scans. Figure.8a Planes of the body with corresponding magnetic resonance imaging (MRI) scans. Median (midsagittal) plane column Frontal (coronal) plane lung Heart lung Liver Transverse plane Aorta Pancreas Spleen Median (midsagittal) plane column Sagittal plane Divides body vertically into right and left parts Produces a sagittal section if cut along this plane Midsagittal (median) plane Cut was made perfectly on midline Parasagittal plane Cut was off-centered, not on midline Rectum Intestines Liver Stomach Spleen Subcutaneous fat layer Spinal cord Rectum Intestines Figure.8b Planes of the body with corresponding magnetic resonance imaging (MRI) scans. Figure.8c Planes of the body with corresponding magnetic resonance imaging (MRI) scans. Transverse (horizontal) plane Divides body horizontally (90 to vertical plane) into superior and inferior parts (top and bottom) Produces a cross section Frontal (coronal) plane Divides body vertically into anterior and posterior parts (front and back) Produces a frontal or coronal section Frontal (coronal) plane lung Heart lung Transverse plane Liver Aorta Pancreas Spleen Liver Stomach Spleen Subcutaneous fat layer Spinal cord 7

8 Figure.9 Dorsal and ventral body cavities and their subdivisions..6 Body Cavities and Membranes Cranial (contains brain) Dorsal body (contains spinal cord) Dorsal body Ventral body Cranial Superior mediastinum Thoracic Pleural (contains heart and lungs) Pericardial within the mediastinum Diaphragm Abdominal (contains digestive viscera) Pelvic (contains urinary bladder, reproductive organs, and rectum) Lateral view Anterior view Ventral body (thoracic and abdominopelvic cavities) Abdominopelvic Body contains internal cavities that are closed to environment Cavities provide different degrees of protection to organs within them Two sets of cavities Dorsal body Ventral body Dorsal Body Cavity Ventral Body Cavity Protects fragile nervous system Two subdivisions Cranial Encases brain Encases spinal cord Houses the internal organs (collectively called viscera) Two subdivisions, which are separated by the diaphragm Thoracic Abdominopelvic Ventral Body Cavity (cont.) Thoracic Two pleural cavities Each surrounds one lung Mediastinum Contains pericardial Surrounds other thoracic organs, such as esophagus, trachea, etc. Pericardial Encloses heart Ventral Body Cavity (cont.) Abdominopelvic Abdominal Contains stomach, intestines, spleen, and liver Pelvic Contains urinary bladder, reproductive organs, and rectum 8

9 Ventral Body Cavity (cont.) Figure.2 The nine abdominopelvic s. Named for specific and organs that they are associated with Pericardium Heart Pleurae Lungs Peritoneum Abdominopelvic Epigastric hypochondriac hypochondriac lumbar Umbilical lumbar iliac Hypogastric iliac (inguinal) (pubic) (inguinal) Nine s delineated by four planes Liver hypochondriac Gallbladder Ascending colon of large intestine lumbar Small intestine Cecum Appendix iliac (inguinal) Epigastric Umbilical Hypogastric (pubic) Diaphragm Spleen hypochondriac Stomach lumbar iliac (inguinal) Transverse colon of large intestine Descending colon of large intestine Initial part of sigmoid colon Urinary bladder Anterior view of the nine s showing the superficial organs Figure. The four abdominopelvic quadrants. Ventral Body Cavity (cont.) upper quadrant (RUQ) upper quadrant (LUQ) Abdominopelvic quadrants and s Quadrants are divisions used primarily by medical personnel Abdominopelvic is sectioned into quarters upper quadrant (RUQ) upper quadrant (LUQ) lower quadrant (RLQ) lower quadrant (LLQ) lower quadrant (RLQ) lower quadrant (LLQ) 9