Chapter 1 - The Human Body: An Orientation
INTRODUCTION
- Anatomy - the study of the structure of body parts and their relationships to one another
- Gross or macroscopic
- Developmental -Traces structural changes throughout life
- Microscopic
- Cytology - study of the cell
- Histology - study of tissues
- Physiology - the study of the function of the body's structural machinery
- Considers the operation of specific organ systems
- Renal - kidney function
- Neurophysiology - workings of the nervous system
- Cardiovascular - operation of the heart and blood vessels
- Structure is always related to function
- The chemical level is the simplest level of organization.
- Atoms, tiny building blocks of matter, combine to form molecules.
- Molecules combine in specific ways to form organelles, which are the basic unit of living cells.
- The cellular level is the smallest unit of life, and varies widely in size and shape according to the cells' function.
- The tissue level is groups of cells having a common function.
- The organ level is made up of discrete structures that are composed of at least two groups of tissues that work together to perform a specific function in the body.
- The organ system level is a group of organs that work closely together to accomplish a specific purpose
- The organismal level is the total of all structures working together to promote life
ORGAN SYSTEMS AND INTERRELATIONSHIPS
- Integument, Skeletal, Muscular, Nervous, Endocrine, Cardiovascular, Lymphatic, Digestive, Respiratory, Urinary, Reproductive
- 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
- Nutrients and oxygen are distributed by the blood
- Metabolic wastes are eliminated by the urinary and respiratory systems
NECESSARY LIFE FUNCTIONS
- Maintaining boundaries - the internal environment remains distinct from the external
- Cellular level - accomplished by plasma membranes
- Organismal level - accomplished by the skin
- Movement - locomotion, propulsion (peristalsis), and contractility
- Responsiveness - ability to sense changes in the environment and respond to them
- Digestion - breakdown of ingested foodstuffs
- Metabolism - all the chemical reactions that occur in the body
- Excretion - removal of wastes from the body
- Reproduction - cellular and organismal levels
- Growth - increase in size of a body part or of the organism
- Differentiation
SURVIVAL NEEDS
- Water - most abundant substance in body
- required for metabolic processes
- required for transport
- regulates body temperature
- Nutrients - supply energy; supply raw materials
- Oxygen - one-fifth of air;
- Heat - form of energy; partly controls rate of metabolic reactions
- Pressure
- atmospheric pressure - important for breathing
- hydrostatic pressure - keeps blood flowing
HOMEOSTASIS - the ability to maintain a relatively stable internal environment in an ever changing outside world
- Homeostatic Mechanisms
monitor aspects of the internal environment and corrects any changes
- T he internal environment of the body is in a dynamic state of equilibrium
- Chemical, thermal, and neural factors interact to maintain homeostasis
- Components
- Variable: the regulated factor or event.
- Receptor: structure that monitors changes in the environment and sends information to the control center.
- Control center: structure that determines the set point for a variable, analyzes input, and coordinates an appropriate response.
- Effector: struture that carries out the response directed by the control center.
- Negative Feedback Mechanisms
- Most homeostatic control mechanisms are negative feedback mechanisms.
- A negative feedback mechanism causes the variable to change in a way that opposes the initial change.
- Both the nervous system and the endocrine system are important to the maintenance of homeostasis.
- The goal of negative feedback mechanisms is to prevent sudden, severe changes in the body.
- Positive Feedback Mechanisms
- A positive feedback mechanism causes the variable to change in the same direction as the original change, resulting in a greater deviation from the set point.
- Positive feedback mechanisms typically activate events that are self-perpetuating.
- Most positive feedback mechanisms are not related to the maintenance of homeostasis.
- Homeostatic imbalance often results in disease.
ANATOMICAL TERMINOLOGY
- Anatomical Position
- a position in which the body is erect, palms face forward, and thumbs point away from the body.
- In anatomical position, right and left refer to the right and left sides of the person viewed.
- In anatomy, anatomical position is always assumed, regardless of the actual position of the body.
- Directional terms -
Are used to explain exactly where one body part is in relation to another
- Regional Terms
- Axial - head, neck, and trunk; Appendicular - appendages or limbs
- Specific Regional Terms:
- Anterior View - in lab book know all the terms
- Posterior View - in lab book know all the terms
- Body sections
- Sagittal /Midsagittal or Median
- Midsagittal or medial - sagittal plane that lies on the midline
- Parasagittal plane: lies offset from the midline
- Frontal or Coronal
- Transverse or Cross
- Oblique
- Body Cavities - Axial Portion
- Dorsal cavity is divided into
- ______________
- _____________________
- Ventral cavity is divided into
- _____________________
- _________________
- _________________
- central area called the ____________
- __________________________
- _______________________________
- ___________________________________
- separated by the _______________________
- Serous Membranes
- Membrane description
- Visceral - membrane covers an organ
- Parietal membrane - lines a cavity or body wall
- Cavity Space between membranes contains serous fluid
- Location of Serous membranes
- Thoracic Membranes
- Around the heart
- membrane on the surface of the heart is _________________
- membrane that lines cavity in which the heart is located ___
- space between the membranes is _________
- Around the lungs
- Membrane on the surface of the lungs _____________
- Membrane that lines cavity in which the lung is located ___
- Space between the membranes is __________
- Abdominopelvic Membranes
- Membrane on the surface of the liver, stomach etc. ___
- Membrane that lines the abdominal cavity _________
- Space between the membranes is __________
- Retroperiotoneal
- Mesentery
- Other Body Cavities - Oral and digestive; Nasal; Orbital; Middle ear; Synovial (joint cavities)
- Nine regions of division
- _____________________ _____________________ __________________
- _____________________ _____________________ __________________
- _____________________ _____________________ __________________
- Four regions of division
- __________________________ ____________________________
- __________________________ ____________________________
Clinical Aplication
- Three noninvasive techniques of palpation, auscultation, and percussion are used to assess certain aspects of body structure and function.
- palpation
- The examiner feels body surfaces with the hands; an example would be pulse and heart rate determination.
- auscultation
- The examiner listens to body sounds to evaluate the functioning of certain organs, as in listening to the lungs or heart.
- percussion
- The examiner taps on the body surface with the fingertips and listens to the resulting echo.
Quiz 1 Lab Page - Page 3
Quiz 2 Lab Pages - Page 4 - Body Orientation and direction; Page 6 - Body cavities and subdivisions; Page 6 - 7 abdominopelvic surface regions; Page 8 - Serous membranes.
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