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The Human Body: An Orientation

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Presentation on theme: "The Human Body: An Orientation"— Presentation transcript:

1 The Human Body: An Orientation

2 Overview of Anatomy and Physiology
Anatomy – the study of the structure of body parts and their relationships to one another Gross or macroscopic Microscopic Developmental Physiology – the study of the function of the body parts

3 Gross Anatomy Regional – study of the structures in one specific part of the body Neck, head, etc Systemic – gross anatomy of the system of the body Surface – study of internal structures as they relate to the overlying skin

4 Microscopic Anatomy Cytology – study of the cell
Histology – study of tissues

5 Developmental Anatomy
Study of the changes in form from conception to physical maturity Embryology – study of developmental changes of the body before birth

6 Specialized Branches of Anatomy
Pathological anatomy – study of structural changes caused by disease Radiographic anatomy – study of internal structures visualized by specialized scanning procedures such as X-ray, MRI, and CT scans Molecular biology – study of anatomical structures at a subcellular level

7 Physiology Systemic physiology –study of the operation of specific organ systems Renal – kidney function Neurophysiology – workings of the nervous system Cardiovascular – operation of the heart and blood vessels Cell physiology Pathological physiology

8 Physiology Understanding physiology also requires a knowledge of physics, which explains electrical currents blood pressure the way muscle uses bone for movement

9 Principle of Complementarity
Anatomy and physiology are closely related What a structure can do depends on its specific form Because enamel is a very hard structure we can masticate hard things

10 Levels of Structural Organization
1 2 4 5 6 3 Smooth muscle cell Molecules Atoms Smooth muscle tissue Epithelial Heart Blood vessels Connective vessel (organ) Cardiovascular system Cellular level Cells are made up of molecules. Tissue level Tissues consist of similar types of cells. Organ level Organs are made up of different types of tissues. Organ system level Organ systems consist of different organs that work together closely. Organismal level The human organism is made up of many organ systems. Chemical level Atoms combine to form molecules. Figure 1.1

11 Levels of Structural Organization
Chemical – atoms combined to form molecules Cellular – cells are made of molecules Tissue –similar types of cells working together Organ – are made of two or more tissues

12 Levels of Structural Organization
Organ system – consists of different organs that work closely together Organism – made up of the organ systems. It is the highest level of organization

13 Integumentary System Forms the external body covering
Composed of the skin, sweat glands, oil glands, hair, and nails Protects deep tissues from injury and synthesizes vitamin D

14 Skeletal System Composed of bone, cartilage, and ligaments
Protects and supports body organs Provides the framework for muscles Site of blood cell formation Stores minerals

15 Muscular System Composed of muscles and tendons
Provides locomotion, and facial expression Maintains posture Produces heat Provides protection and support

16 Nervous System Composed of the brain, spinal column, and nerves
Is the fast-acting control system of the body Responds to stimuli Interprets environmental stimuli

17 Cardiovascular System
Composed of the heart and blood vessels The heart pumps blood The blood vessels transport blood throughout the body

18 Lymphatic System Composed of red bone marrow, thymus, spleen, lymph nodes, and lymphatic vessels Picks up fluid leaked from blood vessels and returns it to blood Disposes of debris in the lymphatic stream Houses white blood cells involved with immunity

19 Respiratory System Composed of the nasal cavity, pharynx, trachea, bronchi, and lungs provides oxygen and removes carbon dioxide Produce sounds

20 Digestive System Composed of the oral cavity, esophagus, stomach, small intestine, large intestine, rectum, anus, liver, etc Digests and absorbs food Eliminates indigestible foodstuffs as feces

21 Urinary System Composed of kidneys, ureteres, urinary bladder, and urethra Eliminates wastes from the body Regulates water, electrolyte, and pH balance of the blood Secrets hormone

22 Endocrine System Composed of pineal, pituitary, thyroid, thymus, adrenal glands, pancreas, ovaries, and testis They secrete hormones that will control metabolism, reproduction, growth, etc

23 Male Reproductive System
Main function is the production of offspring Testes produce sperm and male sex hormones

24 Female Reproductive System
Composed of mammary glands, ovaries, uterine tubes, uterus, and vagina Main function is the production of offspring Ovaries produce eggs and female sex hormones Mammary glands produce milk to nourish the newborn

25 Organ Systems Interrelationships
Nutrients and oxygen are distributed by the blood Metabolic wastes are eliminated by the urinary and respiratory systems Figure 1.2

26 Organ Systems Interrelationships
The integumentary system protects the body from the external environment Digestive and respiratory systems, in contact with the external environment, take in nutrients and oxygen

27 Organ Systems Interrelationships
Nutrients and oxygen are distributed by the blood Metabolic wastes are eliminated by the urinary and respiratory systems

28 Necessary Life Functions
Maintaining boundaries between external and internal environments Cellular level – accomplished by plasma membranes Organismal level – accomplished by the skin Movement – locomotion, propulsion (peristalsis), and contractility

29 Necessary Life Functions
Responsiveness – ability to sense changes in the environment and respond to them Digestion – breakdown of ingested food Metabolism – all the chemical reactions that occur in the body Excretion – removal of wastes from the body

30 Necessary Life Functions
Reproduction – cellular and organismal levels Cellular – an original cell divides and produces two identical daughter cells Organismal – sperm and egg unite to make a whole new person Growth – increase in size of a body part or of the organism

31 Survival Needs Nutrients – needed for energy and cell building
Oxygen – necessary for metabolic reactions Water – provides the necessary environment for chemical reactions

32 Survival Needs Normal body temperature – necessary for chemical reactions to occur at life-sustaining rates Atmospheric pressure – required for proper breathing and gas exchange in the lungs High altitude low atmospheric pressure low oxygen

33 Homeostasis Homeostasis – ability to maintain a relatively stable internal environment in an ever-changing outside world The internal environment of the body is in a dynamic state of equilibrium Chemical, thermal, and neural factors interact to maintain homeostasis

34 Homeostatic Control Mechanisms
Components of control mechanisms: Receptor – monitors the environments and responds to changes (stimuli) Control center – determines the set point at which the variable is maintained Effector – provides the means to respond to stimuli

35 Homeostatic Control Mechanism
Negative Feedback the output shuts off the original stimulus Example: Regulation of room temperature

36 Positive Feedback In positive feedback systems, the output enhances or exaggerates the original stimulus Example: Regulation of blood clotting Figure 1.6

37 Homeostatic Imbalance
Disturbance of homeostasis Diseases Aging Slow down of the body’s control mechanisms increase the risk for diseases

38 Anatomical Position Body erect, feet slightly apart, palms facing forward, thumbs point away from body Figure 1.7a

39 Directional Terms Superior Inferior Anterior Posterior Medial Lateral

40 Directional Terms Proximal Distal Superficial Deep

41 Body Planes Sagittal – divides the body into right and left parts
Midsagittal or medial Frontal or coronal – divides the body into anterior and posterior parts

42 Body Planes Transverse or horizontal (cross section) – divides the body into superior and inferior parts Oblique section – cuts the body diagonally

43 Anatomical Variability
Humans vary slightly in both external and internal anatomy Over 90% of all anatomical structures match textbook descriptions, but: Nerves or blood vessels may be somewhat out of place Small muscles may be missing Extreme anatomical variations are seldom seen

44 Body Cavities Body Cavities Cranial cavity (contains brain) Thoracic
Dorsal body cavity Diaphragm Abdominal cavity (contains digestive viscera) Pelvic cavity (contains bladder, reproductive organs, and rectum) Vertebral cavity (contains spinal cord) Key: Dorsal body cavity Ventral body cavity Thoracic (contains heart and lungs) (a) Lateral view Body Cavities Figure 1.9a

45 Ventral body cavity (thoracic and abdomino- pelvic cavities) Abdomino- Cavity (peritoneal Cavity) Superior mediastinum Pleural cavity Cranial Vertebral Pericardial cavity within the mediastinum Diaphragm Abdominal cavity (contains digestive visceral Pelvic cavity (contains bladder, reproductive organs, and rectum) Thoracic (contains heart and lungs) (b) Anterior view Key: Dorsal body cavity Ventral body cavity Figure 1.9b

46 Body Cavities Dorsal cavity protects the nervous system, and is divided into two subdivisions Cranial cavity – within the skull; encases the brain Vertebral cavity – runs within the vertebral column; encases the spinal cord

47 Body Cavities Ventral cavity houses the internal organs (viscera), and is divided into two subdivisions Thoracic Abdominopelvic

48 Body Cavities Thoracic cavity is subdivided into
Pleural cavities (2)– each houses a lung Mediastinum – between the pleural cavities. Houses esophagus, trachea, etc Pericardial cavity – encloses the heart.

49 Body Cavities Abdominopelvic cavity is separated from the thoracic cavity by the diaphragm It is composed of two subdivisions Abdominal cavity – contains the stomach, intestines, spleen, liver, and other organs Pelvic cavity – lies within the pelvis and contains the bladder, reproductive organs, and rectum

50 Heart Serosa Figure 1.10b



53 Figure 24-2d Mesenteries Falciform ligament Diaphragm Liver Lesser omentum Stomach Pancreas Transverse mesocolon Duodenum Transverse colon Mesentery proper Greater omentum Sigmoid mesocolon Parietal peritoneum Rectum Small intestine Urinary bladder Uterus A sagittal section showing the mesenteries of an adult. Notice that the pancreas, duodenum, and rectum are retroperitoneal. 53

54 Ventral Body Cavity Membranes
Serous membrane or serosa Parietal layer lines internal body walls Visceral serosa covers the internal organs Serous fluid – fills the cavity between the parietal and visceral layers

55 Other Body Cavities Oral and digestive – mouth and cavities of the digestive organs Nasal –located within and posterior to the nose Orbital – house the eyes Middle ear – contains bones (ossicles) that transmit sound vibrations Synovial – joint cavities

56 Abdominopelvic Quadrants
Right upper Left upper Right lower Left lower Figure 1.12

57 Abdominopelvic Regions
Figure 1.11a

58 Organs of the Abdominopelvic Regions
Figure 1.11b

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