Anatomical Terminology: Position, Direction, Planes

• Anatomical terminology is a standardized language employed by healthcare professionals, ensuring clear communication in anatomical and medical settings.

Anatomical Position

• The reference stance involves the body being erect, feet slightly apart, with palms facing forward.
• Serves as a standard reference point for anatomical descriptions.

Anatomical Direction

• Describes the location of structures in relation to others using terms like superior (above), inferior (below), anterior (front), posterior (back), lateral (away from the midline), and medial (towards the midline).
• Proximal refers to being closer to the point of attachment or origin,
• Distal means farther from the point of attachment or origin.

Planes of the Body

• The Coronal (Frontal) Plane divides the body into anterior (front) and posterior (back) sections.
• The Transverse (Cross-Sectional) Plane divides the body into superior (top) and inferior (bottom) sections.
• The Sagittal (Median) Plane divides the body into left and right sections.

Regional Terms

• Designate specific areas of the body for precise location, examples include:
  • Dorsal: Relating to the back
  • Lumbar: Relating to the lower back
  • Umbilical: Relating to the navel
  • Crural: Relating to the shin
  • Orbital: Relating to the eye region
  • Patellar: Relating to the front of the knee
  • Oral: Relating to the mouth
  • Nasal: Relating to the nose
  • Buccal: Relating to the cheek
  • Ocular: Relating to the eye
  • Occipital: Relating to the back of the head
  • Digital/Phalangeal: Relating to the fingers or toes

Respiratory System

• The respiratory system facilitates gas exchange, including oxygen intake and carbon dioxide removal.
• Key components include the lungs, trachea, bronchi, bronchioles, and alveoli, ensuring ventilation and respiration.
• The heart's pulmonary system moves oxygen and carbon dioxide throughout the body.

Lung Anatomy

• Lungs are located in the thoracic cavity, protected by the pleura.
• The right lung has three lobes and is larger than the left due to the heart's placement.
• The left lung has two lobes.
• The trachea connects the larynx to the lungs,
• Bronchi are the main passageways directly attached to the lungs.
• Bronchioles are smaller tubes that branch from the bronchi, connecting to alveoli.

Alveoli

• Tiny air sacs are the sites of gas exchange
  • Type I alveolar cells form the alveolar wall,
  • Type II alveolar cells release surfactant to reduce surface tension.
• The mediastinum is the area between the two lungs where the heart is located.

Ventilation

• Defined as the exchange of oxygen with carbon dioxide in the lungs
• The mechanism involves muscle action and negative pressure including:
  • Diaphragm and intercostal muscles contracting to increase lung volume, decreasing pressure and drawing air in.
  • Relaxation of these muscles reduces lung volume, increases pressure, and expels air.

Ventilation Process

• Periodic inspiration involves the inhalation of air.
• Periodic expiration involves the expulsion of air.
• Tidal Volume is the amount of air breathed in and out during a normal breath.

Gas Exchange

• Location is in the Alveoli.
• Process is by diffusion (passive transport from high to low concentration).
• Oxygen diffuses into the blood capillaries and carbon dioxide diffuses into the alveoli.
• The rate is proportional to the surface area and the concentration gradient, and inversely proportional to the distance between solutions.
• Capillaries connect smaller arteries (arterioles) to smaller veins (venules) and carry out gas exchange.

Alveoli Details

• Tiny air sacs are the sites of gas exchange,
• Two Cell Types: Type I (alveolar wall) and Type II (surfactant release).
• Surfactant reduces surface tension to prevent alveolar collapse.
• High levels of oxygen and a low concentration of carbon dioxide.

Breathing Mechanics

• Diaphragm and Intercostal Muscles contract to increase lung volume and relax to decrease it.
• Inhalation is an active process where air is drawn into the lungs,
• Exhalation is a passive process where air is pushed out of the lungs.
• Residual Volume is the air rich in carbon dioxide that remains trapped in alveoli that mixes with incoming oxygen-rich air.

Cardiovascular/Circulatory System

• Known as the circulatory system, is responsible for circulating blood throughout the body facilitating nutrient distribution and waste removal, and includes the heart, blood vessels (arteries, veins, and capillaries), and blood.

Heart Structure

• Made of cardiac muscle, with four chambers: two atria (upper chambers) and two ventricles (lower chambers).
• Right ventricle pumps blood toward the lungs.
• The right and left ventricles have thicker walls than the atria.

Blood Components

• Plasma contains nutrients, hormones, antibodies, and immune proteins.
• Red Blood Cells contain hemoglobin for oxygen transport.
• White Blood Cells defend against pathogens, including granulocytes (basophils, eosinophils, neutrophils) and agranulocytes (monocytes, lymphocytes)
• Platelets are responsible for blood clotting.

Blood Circulation

• A closed system, blood is pumped by the heart through a network of arteries, veins, and capillaries.
• The Pulmonary Loop carries deoxygenated blood from the right ventricle to the lungs for oxygenation, returning oxygenated blood to the left atrium.
• The Systemic Loop carries oxygenated blood from the left ventricle to the body and returns deoxygenated blood to the right atrium.

Systole and Diastole

• Systole is the contraction of heart muscles.
• Diastole is the relaxation of heart muscles.

Immune System Barriers

• Immune barriers prevent pathogens from entering the body by preventing infections and maintaining overall health, internal defenses are activated

External Barriers

• Prevent pathogens from entering the body with physical and chemical components

Internal Barriers

• Activated when external barriers are breached.
• Include inflammatory responses and defensive cells/chemicals.

Physical Barriers

• Skin serves as a primary physical barrier.
• Mucus traps pathogens.

Chemical Barriers

• Low pH which inhibits pathogen growth.
• Salt promotes a hypertonic environment.
• Enzymes break down pathogens.
• Secretions such as acid, enzymes, and salt prevent entry.

Commensal Microorganisms

• Microscopic organisms that live on the human body without causing harm.
• They create a cellular barrier.

Immune Responses

• The immune system protects the body with innate and adaptive defenses.
• The innate immune system is nonspecific and immediate, while the adaptive immune system is specific and remembers pathogens involving physical barriers, cells, and chemical signals.

Innate Immune System

• Includes nonspecific defense mechanisms present from birth:
  • Physical barriers like skin and mucus membranes;
  • Chemical barriers like low pH, salt, enzymes, and antimicrobial peptides;
  • Internal defenses such as phagocytes, natural killer (NK) cells, interferons, and the complement system.

Adaptive Immune System

• A specific response to pathogens that develops over time involving lymphocytes like T cells and B cells, including:
  • Cellular (cell-mediated) response that destroys infected cells;
  • Humoral (antibody-mediated) response that destroys pathogens in body fluids using antibodies.

Inflammatory Response

• The innate immune response triggered by tissue injury or infection involving the release of histamine, increasing blood flow and attracting phagocytes.
• It can cause fever to speed up the immune response.

Cellular Response

• Part of the adaptive immune system mediated by T cells that targets and destroys cells.

Humoral Response

• Part of the adaptive immune system mediated by B cells.
• Produces antibodies to neutralize pathogens in body fluids.

T Cells

• Lymphocytes that mature in the thymus.
• Key players in cellular immunity.

B Cells

• Lymphocytes that mature in the bone marrow.
• Produce antibodies in humoral immunity.

Antigen-Presenting Cells (APCs)

• Cells that digest pathogens and present antigens to T cells.
• An example includes macrophages which activate helper T cells.

Explore anatomical terminology: standard position, directional terms (superior, inferior, anterior, posterior), and body planes (coronal, transverse, sagittal). Learn how these concepts ensure precise communication among healthcare professionals. Understand the importance of a standard reference point.