Introduction to Anatomy and Physiology

The study of the human body probably began in ancient times as man was concerned about injuries and illnesses. As healers discovered medicines and methods of treatment, they began to understand how the body's parts functioned.

Fig. 1. co

Over time, scientists believed that they could understand the natural forces that drove the human body. With modern technology and medicine, medical providers have named body parts and explained their interactions and functions.

Anatomy is the branch of science that deals with the structure (morphology) of body parts, their forms, and how they are organized. Physiology is the study of the function of body parts. No single part of the body is isolated. In order to entirely understand the function of any body part, the researcher must understand it's role in the whole organism.

Fig. 1.02

The study of the human organism can be subdivided into various levels of organization: Atoms Molecules Macromolecules Cells Organelles Tissues Organs Organ systems Organisms

Metabolism is the sum total of the body processes that break down chemical substances to release energy and assimilate chemical substances and store energy. Movement Responsiveness Growth Reproduction Respiration Digestion Absorption Circulation Assimilation Excretion

In order to maintain metabolism and stay alive, organisms require certain environmental factors: Water - required in chemical reactions, transportation, and as a coolant Foods - required in chemical reactions, as building materials, and as an energy source Oxygen - required to release energy from foods Heat - controls the rate of chemical reactions Pressure - important in breathing

In order to stay alive, living things must maintain a stable internal environment. The maintainence of this stable internal environment is called homeostasis.

Homeostatic mechanisms include: Receptors A set point Effectors

The homeostatic mechanism works through negative feedback.

Fig. 1.07

Homeostatic mechanism regulates body temperature Slide number: 2 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Stimulus Body temperature rises above normal. too high Normal body Temperature 37 o C (98.6 o F)

Homeostatic mechanism regulates body temperature Slide number: 3 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Receptors Thermoreceptors send signals to the control center. Stimulus Body temperature rises above normal. too high Normal body Temperature 37 o C (98.6 o F)

Homeostatic mechanism regulates body temperature Slide number: 4 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Control center The brain detects the deviation from the set point and signals effector organs. Receptors Thermoreceptors send signals to the control center. Stimulus Body temperature rises above normal. too high Normal body Temperature 37 o C (98.6 o F)

Homeostatic mechanism regulates body temperature Slide number: 5 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Control center The brain detects the deviation from the set point and signals effector organs. Receptors Thermoreceptors send signals to the control center. Effectors Skin blood vessels dilate and sweat glands secrete. Stimulus Body temperature rises above normal. too high Normal body Temperature 37 o C (98.6 o F)

Homeostatic mechanism regulates body temperature Slide number: 6 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Control center The brain detects the deviation from the set point and signals effector organs. Receptors Thermoreceptors send signals to the control center. Effectors Skin blood vessels dilate and sweat glands secrete. Stimulus Body temperature rises above normal. Response Body heat is lost to surroundings, temperature drops toward normal. too high Normal body Temperature 37 o C (98.6 o F)

too low Normal body Temperature 37 o C (98.6 o F) Homeostatic mechanism regulates body temperature Slide number: 7 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Stimulus Body temperature drops below normal.

Receptors Thermoreceptors send signals to the control center. too low Normal body Temperature 37 o C (98.6 o F) Homeostatic mechanism regulates body temperature Slide number: 8 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Stimulus Body temperature drops below normal.

Receptors Thermoreceptors send signals to the control center. too low Normal body Temperature 37 o C (98.6 o F) Homeostatic mechanism regulates body temperature Slide number: 9 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Stimulus Body temperature drops below normal. Control center The brain detects the deviation from the set point and signals effector organs.

Receptors Thermoreceptors send signals to the control center. too low Normal body Temperature 37 o C (98.6 o F) Homeostatic mechanism regulates body temperature Slide number: 10 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Stimulus Body temperature drops below normal. Control center The brain detects the deviation from the set point and signals effector organs. If body temperature continues to drop, control center signals muscles to contract involuntarily.

Effectors Skin blood vessels constrict and sweat glands remain inactive. Receptors Thermoreceptors send signals to the control center. too low Normal body Temperature 37 o C (98.6 o F) Homeostatic mechanism regulates body temperature Slide number: 11 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Stimulus Body temperature drops below normal. Effectors Muscle activity generates body heat. Control center The brain detects the deviation from the set point and signals effector organs. If body temperature continues to drop, control center signals muscles to contract involuntarily.

Effectors Skin blood vessels constrict and sweat glands remain inactive. Receptors Thermoreceptors send signals to the control center. too low Normal body Temperature 37 o C (98.6 o F) Homeostatic mechanism regulates body temperature Slide number: 12 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Stimulus Body temperature drops below normal. Response Body heat is conserved, temperature rises toward normal. Effectors Muscle activity generates body heat. Control center The brain detects the deviation from the set point and signals effector organs. If body temperature continues to drop, control center signals muscles to contract involuntarily.

The human body is subdivided into 2 main units: axial - head, neck, and trunk appendicular - upper and lower limb systems

The body contains a number of organ cavities: Cranial cavity Vertebral canal Thoracic cavity: Mediastium Pericardial cavity Plueral cavities Abdominopelvic Cavity: Abdominal cavity Pelvic cavity Smaller cavities within the head include the: Oral cavity Nasal cavity Orbital cavities Middle ear cavities

Fig. 1.08a

Fig. 1.08b

Fig. 1.09

The diaphram separates the thoracic cavity and the abdomenopelvic cavity.

Membranes lining the cavities may be refered to as: Parietal - Forms a lining Visceral - Covers the organs

Parietal pleura - lines the pleural cavity Visceral pleura - covers the lungs Pleural cavity - found between the parietal and visceral pleura Parietal pericardium - lines the pericardial cavity Visceral pericardium - covers the heart Pericardial cavity - found between the parietal and visceral pericardium Parietal peritoneum - lines the abdominal cavity Visceral peritoneum - covers the digestive organs Peritoneal cavity - found between the parietal and visceral pericardium

Fig. 1.10

The human body contains eleven well organized systems: integumentary system – muscular system - nervous system - endocrine system - cardiovascular system - lymphatic system - digestive system - respiratory system - urinary system - reproductive system -

Anatomical position - Human standing erect, face forward, arms at side with palms forward

Based on anatomical position, a number of body regions can be described: Superior Inferior Anterior Posterior Medial Lateral Proximal Distal Superficial Deep

Based on anatomical position, a number of body regions can be described by certain planes: Sagittal - divides right and left sections Transverse - divides upper and lower sections Coronal - divides front and back sections

The trunk can be divided into certain regions: Epigastric - upper midportion Hypochondriac regions - lie on each side of the epigastric region Umbilical region - midregion of the trunk Lumbar regions - lie on each side of the umbilical region Hypogastric region - lower midportion Iliac regions - lie on each side of the hypogastric region

The following studies deal with anatomy, physiology, diseases, and disorders of the listed systems. Cardiology: Study of the heart and heart related diseases. Cytology: Study of the cell. Dermatology: Study of the skin. Endocrinology: Study of the hormone-secreting glands. Epidemiology: Study of the distribution of contagious disease. Gastroenterology: Study of the stomach and intestines.

Geriatrics: Study of the aged. Gynecology: Study of the female reproductive system. Hematology: Study of the blood. Histology: Study of tissues. Immunology: Study of the body's resistance to disease. Neonatology: Study of newborns. Nephrology: Study of the kidneys. Neurology: Study of the nervous system. Obstetrics: Study of pregnancy and children. Oncology: Study of cancer. Opthalmology: Study of the eye. Orthopedics: Study of the skeleton and muscles.

Orthopedics: Study of the skeleton and muscles. Pathology: Study of disease. Pediatrics: Study of children. Pharmacology: Study of drugs. Podiatry: Study of the feet. Psychiatry: Study of the mind. Radiology: Study of X-Rays. Toxicology: Study of poisons. Urology: Study of the kidneys and the male urinary system.