A&P Chapter 1: The Human Body: An Orientation

Scientific discipline that investigates the body's structures and the relationships among them
Scientific investigation of the processes or functions of living things (how the body parts work)
Gross Anatomy
Structures examined without a microscope.
ex: Regional, System, Surface Anatomy
Regional Anatomy
Studies all structures in a particular area of the body
System Anatomy
Studies just one system
ex:cardiovascular, nervous, muscular
Surface Anatomy
Studies internal structures as they relate to overlying skin (visible muscle masses or veins seen on surface)
Microscopic Anatomy
Structures seen with the microscope
Microscopic study of cells
Microscopic study of tissues
Development Anatomy
Studies anatomical and physiological development throughout life
Study of development before birth
The act of listening to sounds arising within the body
ex: using a stethoscope
Examine part of the body by touch
Cell Physiology
Examines processes in cells
Focuses on the nervous system
(2) Subjects that encompass both anatomy and physiology
Pathology: structural and functional changes caused by disease
Exercise Physiology: changes in structure and function caused by exercise
(6) Levels of Structural and Functional Organization
1. Chemical Level: interaction of atoms, molecules, organelles
2. Cellular Level: structural and functional unit of living organisms; single cells
3. Tissue Level: Group of similar cells and the materials surrounding them
4. Organ Level: Two or more tissues functioning together
5. Organ System Level: group of organs functioning together
6. Organismal Level: any living thing
(4) Types of Tissue
1. Epithelial
2. Connective
3. Muscle
4. Nervous
(11) Organs Systems
1. Integumentary: skin, hair, nails
2. Skeletal: bones, joints
3. Muscular: skeletal muscle
4. Nervous: brain, spinal cord, nerves
5. Endocrine: glands, pancreas, testes/ovaries
6. Cardiovascular: heart, blood vessels
7. Lymphatic/ Immunity: marrow, thymus, lymphatic vessels, spleen, lymph nodes
8. Respiratory: nasal cavity, pharynx, larynx, trachea, lungs
9. Digestive: oral cavity, esophagus, liver, stomach, intestinal tract
10. Urinary: kidney, liver, bladder, urethra
11. Reproductive: sex organs
(9) Essential Characteristics of Life
1. Maintaining boundaries
2. Movement
3. Responsiveness
4. Digestion
5. Metabolism
6. Excretion
7. Reproduction
8. Growth
9. Organization
Maintaining Boundaries
Separation between internal and external environments (ie. plasma membrane, skin)
Movement of body parts (via skeletal muscle), substances (blood), smooth muscle (digestion), cells (chemotaxis, contractility of muscle cells)
Ability to sense and respond to stimuli
Breakdown of ingested foodstuffs, followed by absorption of simple molecules
All chemical reactions in the body
-Catabolism (breakdown)
-Anabolism (synthesis)
Removal of wastes from metabolism and digestion
-At cellular level: division of cells for growth or repair
-At organismal level: production of offspring
Increase in size of a cell, body part, or of organism
Condition in which parts of the organism have specific relationships to each other and parts interact to perform specific functions
(5) Survival Needs
1. Nutrients: chemicals for energy and cell-building
2. Oxygen: Essential for release of energy from foods
3. Water: Provides aqueous environment needed for chemical reactions
4. Normal body temperature: 37 celsius
5. Appropriate air pressure: required for adequate breathing and gas exchange in the lungs
-Existence and maintenance of a relatively constant environment within the body despite continuous changes in the environment
-Dynamic state of equilibrium, always readjusting as needed
Set Point
The ideal normal value of a variable
(3) Components of a feedback system
Receptor: sensor that monitors value of some variable
Control Center: receives information about variable from receptor, establishes set point, controls effector
Effector: receives output from control center and responds to change value of the variable
Deviation from set point; detected by receptor
Produced by the effector to change the variable
Negative Feedback
Response reduces or shuts off original stimulus (ex. regulation of body temp. or blood glucose)
(5) Steps of Negative Feedback
1. Stimulus
2. Receptor detects change
3. Information sent to control center
4. information sent to effector
5. Effector reduces effect of stimulus and returns variable to homeostatic level
Afferent Pathways
Incoming signal
Efferent Pathways
Outgoing signal (e for exit)
Positive Feedback
Response enhances or exaggerates original stimulus
Pos. Feedback in Childbirth
-Near end of pregnancy, baby is larger in size, stretches uterus, and presses down on the uterus
-Stimulates release of oxytocin
-Causes contractions, leading to increased uterine pressure
-Repeats until child it born, when pressure is relieved
Homeostatic Imbalance
-Disturbance of homeostasis
-Increased risk of disease
-contributes to changes associated with aging
Standard Anatomical Position
Body erect, face forward, feet slightly apart, palms face forwards with thumbs pointing away from body
Supine Position
Lying face upward
Prone Postion
Lying face downward
Superior (cranial) vs. Inferior (caudal)
Towards or away from head
Anterior (ventral) vs. Posterior (dorsal)
Front vs. back
Medial vs. Lateral
Closer vs. further from midline
Proximal vs. Distal
Nearest vs. distant
-Used to describe distance from origin of body part or point of attachment
Superficial vs. Deep
Relative to the surface of the body
(2) Major Divisions of Body
Axial: head, neck, and trunk
Appendicular: limbs (legs and arms)
Head region
Neck area
Upper Limb
Shoulder to wrist
Chest to hip
Waist and hip area
Gential area
Lower Limb
Hip to ankle
(dorsal) entire back
Sagittal plane
-Vertical line dividing body into right and left parts
-Median plane= sagittal lying exactly in midline
-Parasagittal= offset from midline
Frontal (coronal) plane
Vertical plane dividing body into anterior and posterior sections
Transverse plane
-horizontal plane dividing body into superior and inferior sections (produces a cross-section)
Oblique sections
Cuts made diagonally between horizontal and vertical planes
(2) Sets of internal body cavities
-Dorsal body cavity
-Ventral cavity
(2) Subdivisions of Dorsal Body Cavity
-Cranial cavity (encases brain)
-Vertebral cavity (encases spinal cord)
(2) Subdivisions of Ventral Body Cavity
Parts of Thoracic Cavity
-Pleural Cavities (each surrounds one lung)
-Mediastinum (pericardial cavity, and surrounds other thoracic organs
Parts of Abdominopelvic Cavity
-Abdominal Cavity (contains stomach, intestines, spleen, liver)
-Pelvic Cavity (urinary bladder, reproductive organs, rectum)
(4) Abdominopelvic Quadrants
-Right upper quadrant (RUQ)
-Left Upper Quadrant (LUQ)
-Right Lower Quadrant (RLQ)
-Left Lower Quadrant (LLQ)
(9) Abdominopelvic Regions in order of top left to bottom right
-Right hypochondriac region
-Epigastric region
-Left Hypochondriac region
-Right Lumbar region
-Umbilical region
-Left Lumbar region
-Right Iliac region
-Hypogastric region
-Left Iliac region
-Thin, double-layered membranes that cover the surfaces in the ventral body cavity
-Double layers are separated by slit-like cavity filled with serous fluid
-Fluid is secreted by both layers of membrane
-reduce friction during rubbing
Parietal serosa
Lines internal body cavity walls
Visceral serosa
Covers internal organs (viscera)
(3) Examples of serous membranes
-Pericardium: heart
-Pleurae: Lungs
-Peritoneum: Abdominopelvic cavity
(5) Smaller body cavities
-Oral and digestive cavities
-Nasal cavity
-Orbital cavities
-Middle ear cavities
-Synovial (joint) cavities (only one not exposed to environment)
Radiograph (X-ray)
Shadowy negative image of internal body structures- dense structures absorb the X rays most effectively and thus appear as light areas on the film
Ultrasound (US)
Use pulses of sound waves that cause "echoes" when reflected and scattered by the body parts - these echoes are computer-analyzed to construct blurry outlines of body organs
Computed Tomography (CT or CAT scan)
X ray tube rotates person, confining X ray beam to one "slice" of body -- provides a detailed cross-sectional picture of body region being scanned (can add color artificially)
Dynamic Spatial Reconstruction (DSR)
3-D version of CT scan using ultrafast imaging -- Can visualize beating hearts and blood flowing through blood vessels
Digital Subtraction Angiography (DSA)
Provides unobstructed view of small arteries -- Conventional radiographs taken before and after contrast, then computer subtracts the "before" image from the "after" image, eliminating structures that obscure the vessel
Magnetic Resonance Imaging (MRI)
Uses magnetism and radio waves to distinguish body tissues based on water content -- dense structures do not show up on MRI, allowing visualization of brain, etc.
Positron Emission Tomography (PET)
Uses radioactively labeled glucose to calculate metabolic activity of cells