Body Structure

• LEVELS OF ORGANIZATION

  1. Cell
  2. Tissue
  3. Organ
  4. System
  5. Organism
• The cell is the structural and functional unit of life.
• CYTOLOGY - the study of the body at a cellular level.
• CYT/O = cell

  -logy = study
• Tissues are a group of cells that perform specialized activity.
• HISTOLOGY - study of tissues
• HIST/O = tissue

  -logy = study of
• COMMON TYPES OF TISSUES

  1. Epithelial
  2. Connective
  3. Muscle
  4. Nervous
• Epithelial tissue is a tissue that covers surfaces and lines cavities where it may protect, absorb, and/or secrete.
• The three basic shapes of epithelial cells:

  1. squamous (flat)
  2. cuboidal (cubes)
  3. columnar (columns)
• Connective tissue is tissue that supports other tissues, holds tissues together, or fills spaces.
• blood is considered to be a connective tissue.
• Muscles are made up of muscle tissues. Muscle tissues and the muscles they make up are specialized to contract. Because of their ability to shorten (contract), muscles are able to produce motion.
• Types of Muscle Tissue:

  • Skeletal- striated, voluntary
  • Cardiac- striated, involuntary
  • Smooth- not striated, involuntary
• Nervous tissue is a collection of cells that respond to stimuli and transmit information
• A neuron or nerve cell is the cell of the nervous tissue that actually picks up and transmits a signal from one part of the body to another
• Levels of Organization

  A) Cells

  B) Tissues

  C) Organs

  D) Systems

  E) Organism

  
• Nerve Cell

  A) Dendrite

  B) Cell Body

  C) Axon

  D) Node of Ranvier

  E) Schwann Cell

  F) Axon Terminal

  G) myelin

  H) nucleus

  
• Organs are body structure composed of at least two different tissue types that perform specialized functions.
• A body system is composed of at least one organ and accessory structures that have similar or interrelated functions.
• The highest level of organization is the organism. This is a complex living entity capable of independent existence.
• From the clinical point of view, disease is a pathological or morbid condition of the body that presents a group of signs, symptoms and clinical findings.
• Signs are any abnormality of bodily structure or function that is observable by the physician, (objective)whether evident to the patient or not.
• Any distress, abnormality, or malfunction experienced by the patient as a result of illness; it may entirely be subjective (headache) or it may be partly or entirely evident to others (vomiting, paralysis).
• Pathology is the study of diseases.

  
  

  Path/o/ - disease, suffering

  Logy - study

  
  

  Pathogenesis is the study of the progression or development of a disease.

  
  

  Path/o/- disease

  Genesis - production
• Etiology is the science and study of the causes of disease and their mode of operation.
• A pathogen is any virus, microorganism, or other substance causing disease.

  
  

  path/o –disease

  -gen – produce
• PROGNOSIS vs. DIAGNOSIS

  Prognosis – is a forecast of probable course and/or outcome of a disease.

  
  

  Diagnosis- is the determination of the nature and cause of a disease, injury, or congenital defect.
• The anatomical position is an artificial posture of the human body. This position is used as a standard reference throughout the medical profession.
• A body in anatomic position is standing erect, eyes looking forward, with arms hanging to the side, and palms facing to the front. Despite definition, the term also applies when lying or sitting.
• An anatomical plane of the body is an imaginary flat surface that passes through the body at different places to divide it for anatomical purposes.

  A) Sagittal

  B) Coronal

  C) Transverse

  
• Sagittal Plane (vertical plane) are vertical planes parallel to midsagittal plane that passes through the body from front to back
• In medical terms lateral means 'outside', and medial 'inside' in the sense of lying in the middle.
• Coronal Plane (frontal plane) - A vertical plane at right angle to a sagittal plane, dividing the body into anterior (front) and posterior (back) portions as though cutting through a corona or halo
• Transverse Plane (horizontal plane) - cutting across body or body part crosswise. Transverse sections run top to bottom (superior to inferior)
• Body cavities are compartments of the human body. The cavities, or spaces, of the body contain the internal organs or viscera.

  A) Ventral Cavity

  B) Dorsal Cavity

  C) Thoracic

  D) abdominal

  
• Two main cavities:

  1. Ventral
  2. Dorsal
• Ventral is the larger cavity and is subdivided into two parts (thoracic and abdominopelvic cavities) by the diaphragm, a dome-shaped respiratory muscle.
• The smaller cavity is called the dorsal cavity. As its name implies, it contains organs lying more posterior in the body. The dorsal cavity can be divided into two portions. The upper portion, or the cranial cavity, houses the brain, and the lower portion, or vertebral canal houses the spinal cord.
• The dorsal cavity is subdivided into:

  • cranial cavity
  • spinal cavity

  A) cranial

  B) spinal