Anatomy and Physiology Anatomy What Describes the structures

Anatomy and Physiology • Anatomy (What) – Describes the structures of the body • What they are made of • Where they are located • Associated structures • Physiology (How) – Is the study of: • Functions of anatomical structures • Individual and cooperative functions

Relationships between Anatomy and Physiology • Anatomy – Gross anatomy, or macroscopic anatomy, examines large, visible structures – Microscopic anatomy examines cells and molecules • Cytology: study of cells and their structures – cyt- = cell • Histology: study of tissues and their structures

Relationships between Anatomy and Physiology • Physiology – Cell physiology: processes within and between cells – Organ physiology: functions of specific organs – Systemic physiology: functions of an organ system – Pathological physiology: effects of diseases

Levels of Organization • The Chemical (or Molecular) Level – Atoms are the smallest chemical units – Molecules are a group of atoms working together • The Cellular Level – Cells are a group of atoms, molecules, and organelles working together • The Tissue Level – A tissue is a group of similar cells working together • The Organ Level – An organ is a group of different tissues working together

Levels of Organization • The Organ System Level – An organ system is a group of organs working together – Humans have 11 organ systems • The Organism Level – A human is an organism

Figure 1 -1 Levels of Organization Cellular Level Chemical and Molecular Levels Heart muscle cell Protein filaments Complex protein molecule Atoms in combination

Figure 1 -1 Levels of Organization Organ Level Tissue Level Cardiac muscle tissue The heart The cardiovascular system Organ system level Organism level

Anatomical Terminology • Superficial Anatomy – Locating structures on or near the body surface • Anatomical Landmarks – Anatomical position: hands at sides, palms forward – Supine: lying down, face up – Prone: lying down, face down

Anatomical Terminology • Superficial Anatomy – Anatomical Landmarks • References to palpable structures – Anatomical Regions • Body regions • Abdominopelvic quadrants • Abdominopelvic regions – Anatomical Directions • Reference terms based on subject

Figure 1 -5 a Anatomical Landmarks Frontal or forehead Cranial or skull Cephalic or head Nasal or nose Ocular, orbital or eye Otic or ear Buccal or cheek Facial or face Cervical or neck Oral or mouth Mental or chin Thoracic or thorax, chest Axillary or armpit Mammary or breast Brachial or arm Abdominal (abdomen) Umbilical or navel Antecubital or front of elbow Anterior view Trunk

Figure 1 -5 a Anatomical Landmarks Antebrachial or forearm Pelvic (pelvis) Trunk Carpal or wrist Palmar or palm Manual or hand Pollex Digits or thumb (phalanges) or fingers (digital or phalangeal) Patellar or kneecap Inguinal or groin Pubic (pubis) Femoral or thigh Crural or leg Tarsal or ankle Digits (phalanges) or toes (digital or phalangeal) Hallux or great toe Pedal or foot Anterior view

Figure 1 -5 b Anatomical Landmarks Cephalic or head Acromial or shoulder Dorsal or back Cervical or neck Olecranal or back of elbow Upper limb Posterior view

Figure 1 -5 b Anatomical Landmarks Upper limb Lumbar or loin Gluteal or buttock Lower limb Popliteal or back of knee Sural or calf Calcaneal or heel of foot Plantar or sole of foot Posterior view

Figure 1 -6 a Abdominopelvic Quadrants and Regions Right Upper Quadrant (RUQ) Left Upper Quadrant (LUQ) Right Lower Quadrant (RLQ) Left Lower Quadrant (LLQ) Abdominopelvic quadrants. The four abdominopelvic quadrants are formed by two perpendicular lines that intersect at the navel. The terms for these quadrants, or their abbreviations, are most often used in clinical discussions.

Figure 1 -6 b Abdominopelvic Quadrants and Regions Right hypochondriac region Right lumbar region Right inguinal region Epigastric region Umbilical region Hypogastric (pubic) region Left hypochondriac region Left lumbar region Left inguinal region Abdominopelvic regions. The nine abdominopelvic regions provide more precise regional descriptions.

Figure 1 -6 c Abdominopelvic Quadrants and Regions Liver Gallbladder Stomach Spleen Large intestine Small intestine Appendix Urinary bladder Anatomical relationships. The relationship between the abdominopelvic quadrants and regions and the locations of the internal organs are shown here.

Figure 1 -7 Directional References Superior Cranial Right Left Proximal Anterior or ventral Posterior or dorsal Lateral Caudal Medial Proximal Distal Inferior A lateral view. Distal An anterior view. Arrows indicate important directional terms used in this text; definitions and descriptions are given in Table 1 2.

Table 1 -2 Directional Terms

Anatomical Terminology • Sectional Anatomy – Planes and sections • Plane: a three-dimensional axis • Section: a slice parallel to a plane • Used to visualize internal organization and structure • Important in radiological techniques (eg. MRI)

Figure 1 -8 Sectional Planes Frontal plane Sagittal plane Transverse plane

Body Cavities • Essential Functions of Body Cavities 1. Protect organs from accidental shocks 2. Permit changes in size and shape of internal organs • Ventral body cavity – Divided by the diaphragm • Thoracic cavity • Abdominopelvic cavity

Body Cavities • Serous Membranes – Line body cavities and cover organs – Consist of parietal layer and visceral layer • Parietal layer — lines cavity • Visceral layer — covers organ

Figure 1 -10 b The Ventral Body Cavity and Its Subdivisions Visceral pericardium Heart Pericardial cavity Parietal pericardium Air space Balloon

Figure 1 -9 Relationships among the Subdivisions of the Ventral Body Cavity • Provides protection • Allows organ movement • Linings prevent friction Subdivides during development into Abdominopelvic Cavity Thoracic Cavity Surrounded by chest wall and diaphragm Peritoneal Cavity Right Pleural Cavity Mediastinum Left Pleural Cavity Surrounds right lung Contains the trachea, esophagus, and major vessels Surrounds left lung Pericardial Cavity Surrounds heart Extends throughout abdominal cavity and into superior portion of pelvic cavity Abdominal Cavity Pelvic Cavity Contains many digestive glands and organs Contains urinary bladder, reproductive organs, last portion of digestive tract

Figure 1 -10 a The Ventral Body Cavity and Its Subdivisions POSTERIOR ANTERIOR Pleural cavity Thoracic cavity Pericardial cavity Diaphragm Peritoneal cavity Abdominal cavity Pelvic cavity Abdominopelvic cavity

Figure 1 -10 c The Ventral Body Cavity and Its Subdivisions ANTERIOR Pericardial cavity Pleural cavity Parietal pleura Right lung Left lung Mediastinum Spinal cord POSTERIOR

Body Cavities • The Thoracic Cavity – Right and left pleural cavities • Contain right and left lungs – Mediastinum • Upper portion filled with blood vessels, trachea, esophagus, and thymus • Lower portion contains pericardial cavity – The heart is located within the pericardial cavity

Figure 1 -10 c The Ventral Body Cavity and Its Subdivisions ANTERIOR Pericardial cavity Pleural cavity Parietal pleura Right lung Left lung Mediastinum Spinal cord POSTERIOR

Figure 1 -10 a The Ventral Body Cavity and Its Subdivisions POSTERIOR ANTERIOR Pleural cavity Thoracic cavity Pericardial cavity Diaphragm Peritoneal cavity Abdominal cavity Pelvic cavity Abdominopelvic cavity

Body Cavities • The Abdominopelvic Cavity – Abdominal cavity — superior portion • Diaphragm to top of pelvic bones • Contains digestive organs • Retroperitoneal space – Area posterior to peritoneum and anterior to muscular body wall – Contains pancreas, kidneys, ureters, and parts of the digestive tract

Body Cavities • The Abdominopelvic Cavity – Pelvic cavity — inferior portion • Within pelvic bones • Contains reproductive organs, rectum, and bladder

Figure 1 -10 a The Ventral Body Cavity and Its Subdivisions POSTERIOR ANTERIOR Pleural cavity Thoracic cavity Pericardial cavity Diaphragm Peritoneal cavity Abdominal cavity Pelvic cavity Abdominopelvic cavity

Homeostasis • Homeostasis – All body systems working together to maintain a stable internal environment • Systems respond to external and internal changes to function within a normal range (body temperature, fluid balance)

Homeostasis • Mechanisms of Regulation – Autoregulation (intrinsic) • Automatic response in a cell, tissue, or organ to some environmental change – Extrinsic regulation • Responses controlled by nervous and endocrine systems

Homeostasis • Receptor – Receives the stimulus • Control center – Processes the signal and sends instructions • Effector – Carries out instructions

Figure 1 -2 The Control of Room Temperature RECEPTOR Normal condition disturbed Thermometer Information affects STIMULUS: Room temperature rises Normal room temperature RESPONSE: Room temperature drops Normal condition restored EFFECTOR Air conditioner turns on 20° 30° 40° Sends commands to In response to input from a receptor (a thermometer), a thermostat (the control center) triggers an effector response (either an air conditioner or a heater) that restores normal temperature. In this case, when room temperature rises above the set point, thermostat turns on the air conditioner, and the temperature returns to normal. Room temperature (°C) CONTROL CENTER (Thermostat) HOMEOSTASIS Air conditioner turns on turns off 22 Normal range Time With this regulatory system, room temperature fluctuates around the set point.

Negative and Positive Feedback • The Role of Negative Feedback – The response of the effector negates the stimulus – Body is brought back into homeostasis • Normal range is achieved

Figure 1 -3 Negative Feedback in the Control of Body Temperature RECEPTORS Temperature sensors in skin and hypothalamus Normal temperature disturbed Information affects CONTROL CENTER STIMULUS: Body temperature rises HOMEOSTASIS RESPONSE: Increased heat loss, body temperature drops Normal temperature restored EFFECTORS • Sweat glands in skin increase secretion • Blood vessels in skin dilate Sends commands to Events in the regulation of body temperature, which are comparable to those shown in Figure 1 2. A control center in the brain (the hypothalamus) functions as a thermostat with a set point of 37°C. If body temperature exceeds 37. 2°C, heat loss is increased through enhanced blood flow to the skin and increased sweating. Body temperature (°C) Thermoregulatory center in brain Normal body temperature 37. 2 37 36. 7 Vessels dilate, constrict, sweating increases decreases Normal range Time The thermoregulatory center keeps body temperature fluctuating within an acceptable range, usually between 36. 7 and 37. 2°C.

Negative and Positive Feedback • The Role of Positive Feedback – The response of the effector increases change of the stimulus – Body is moved away from homeostasis • Normal range is lost – Used to speed up processes

Figure 1 -4 Positive Feedback: Blood Clotting accelerates Positive feedback loop Chemicals Damage to cells in the blood vessel wall releases chemicals that begin the process of blood clotting. The chemicals start chain reactions in which cells, cell fragments, and soluble proteins in the blood begin to form a clot. As clotting continues, each step releases chemicals that further accelerate the process. Blood clot This escalating process is a positive feedback loop that ends with the formation of a blood clot, which patches the vessel wall and stops the bleeding.

Negative and Positive Feedback • Systems Integration – Systems work together to maintain homeostasis • Homeostasis is a state of equilibrium – Opposing forces are in balance – Dynamic equilibrium — continual adaptation • Physiological systems work to restore balance – Failure results in disease or death

Table 1 -1 The Roles of Organ Systems in Homeostatic Regulation

• Come up with 5 multiple choice questions (a, b, c, d) that you think would be good for the quiz on Monday. Be sure to include the correct answer on the back of the sheet. • Write them on a separate sheet of paper with your name on it. This will be a graded assignment.