TEAS Anatomy and Physiology

Respiratory System

Basic Functions of the Respiratory System

• The respiratory system plays a crucial role in gas exchange, providing oxygen to the lungs and removing carbon dioxide from the body.
• The main functions of the respiratory system are:
  
  • Gas Exchange: The process of exchanging oxygen (O₂) and carbon dioxide (CO₂) between the air in the lungs and the blood.
  • Respiration: The entire process of obtaining oxygen from the environment and eliminating carbon dioxide from the body.
  • Breathing / Ventilation: The physical process of moving air in and out of the lungs.

Basic Structure of the Respiratory System

• The respiratory system consists of several key structures that facilitate breathing and gas exchange.
• Some of the most important structures are:
  
  • Nose: The structure that provides air for breathing, filters and conditions incoming air, and supports the sense of smell.
  • Pharynx (Throat): A muscular tube that serves as a passageway for both air and food and plays a role in swallowing and voice production.
  • Epiglottis: Flap of cartilage that covers the larynx during swallowing to keep food out of the airway.
  • Larynx (Voice Box): Cartilage structure between the pharynx and the trachea. It houses the vocal cords.
  • Trachea (Windpipe): A flexible tube that allows air to pass from the larynx to the bronchi.
  • Primary Bronchi: The two main tubes branching from the trachea that distribute air to each lung.
  • Bronchioles: Smaller branches of the bronchi that lead air to the alveoli and help regulate airflow within the lungs.
  • Diaphragm: A dome-shaped muscle that separates the chest from the abdomen and is the main muscle responsible for breathing.
  • Lungs: Cone-shaped organs in the chest that bring oxygen into the bloodstream and remove carbon dioxide.
  • Alveoli: Small air sacs at the end of bronchioles where gas exchange occurs, allowing oxygen to enter the blood and carbon dioxide to be exhaled.

Cardiovascular System

Basic Functions of the Cardiovascular System

• The primary functions of the cardiovascular system are:
  
  • Transport of Blood, Oxygen, and Nutrients: The cardiovascular system moves blood, oxygen, nutrients, and hormones through the body while removing waste.
  • Heart Cycle and Blood Flow Regulation: The heart beats in cycles of systole (contraction) and diastole (relaxation), controlled by the pacemaker (SA node).
  • Gas Exchange and pH Balance: Red blood cells transport oxygen and carbon dioxide, and the body maintains pH balance through the bicarbonate system.
  • Immune Function and Fluid Balance: The lymphatic system circulates and filters interstitial fluid (fluid between cells) to protect against pathogens.
  • Blood Clotting and Injury Repair: Platelets prevent blood loss by forming clots at injury sites.

Basic Structure of the Cardiovascular System

• The cardiovascular system is composed of the heart, blood vessels, and blood, working together to supply oxygen, nutrients, and hormones to the body while removing waste products.
• Blood flows through four chambers and passes through four specific valves along its path through the heart.
  
  • Chambers
    
    • Right Atrium (Upper Chamber): Receives deoxygenated blood from the body via the vena cava.
    • Left Atrium (Upper Chamber): Receives oxygenated blood from the lungs via the pulmonary veins.
    • Right Ventricle (Lower Chamber): Pumps deoxygenated blood to the lungs through the pulmonary artery for oxygenation.
    • Left Ventricle (Lower Chamber): Pumps oxygenated blood to the body through the aorta.
  • Valves
    
    • Tricuspid Valve: Located between the right atrium and right ventricle. Prevents backflow of blood from the right ventricle to the right atrium during ventricular contraction.
    • Pulmonary Valve: Located between the right ventricle and the pulmonary artery. Prevents backflow of blood into the right ventricle after it has been pumped into the pulmonary artery.
    • Mitral Valve: Located between the left atrium and left ventricle. Prevents backflow of blood from the left ventricle to the left atrium during ventricular contraction.
    • Aortic Valve: Located between the left ventricle and the aorta. Prevents backflow of blood into the left ventricle after it has been pumped into the aorta.
• Arteries: Carry blood away from the heart.
• Veins: Carry blood toward the heart.
• Capillaries: Microscopic vessels where exchange with tissues occurs.

Blood Flow Through the Cardiovascular System

• Blood flows through the heart in two main circuits:
  • Pulmonary Circulation: Carries deoxygenated blood from the right side of the heart to the lungs for oxygenation and returns oxygenated blood to the left side of the heart.
  • Systemic Circulation: Delivers oxygenated blood from the left side of the heart to the rest of the body and returns deoxygenated blood to the right side of the heart.

Digestive System

Basic Functions of the Digestive System

• The gastrointestinal (GI) system, also known as the digestive system, is responsible for breaking down food, absorbing nutrients, and eliminating waste from the body.
• The main functions of the digestive system include:
  
  1. Ingestion and Mechanical Breakdown of Food
  2. Swallowing and Transport of Food
  3. Chemical Digestion in the Stomach
  4. Absorption of Nutrients in the Small Intestine
  5. Water Absorption and Waste Formation in the Large Intestine
  6. Elimination of Waste (Defecation)

Basic Structure of the Digestive System

• The digestive system is broken down into two parts:
  
  1. Digestive Tract (Alimentary Canal)
     
     • Mouth: Entry point for food into the digestive tract.
     • Pharynx: Muscular tube about 4.5-5 inches long that connects the nasal and oral cavities to the larynx and esophagus. 
     • Esophagus: Transports the bolus from the pharynx (throat) to the stomach using rhythmic contractions known as peristalsis.
     • Stomach: A muscular organ that stores and mechanically breaks down food.
     • Small Intestine: Breaks down food, absorbs nutrients, extracts water, and moves food along the GI tract.
     • Large Intestine: Reabsorbs water and produces mucus for fecal movement.
     • Rectum: Stores feces prior to elimination.
     • Anus: Opening for elimination of waste.
  2. Accessory Organs
     
     • Teeth: Hard and bony structures in the mouth used to bite and chew food.
     • Tongue: Flexible and muscular organ in the mouth that helps with taste, chewing, swallowing, and speech.
     • Salivary Glands: Small organs in the head and neck that produce saliva.
     • Liver: Largest internal organ in the human body. Performs tasks like filtering blood, processing nutrients, and fighting infections. Also produces bile, which emulsifies fat.
     • Gallbladder: Stores and concentrates bile produced by the liver.
     • Pancreas: Gland located in the upper abdomen behind the stomach that manages digestion and blood sugar regulation. It also secretes enzymes that break down carbohydrates, proteins, and fats.

Nervous System

Basic Functions of the Nervous System

• The nervous system is essential for controlling and coordinating bodily functions, processing sensory information, and enabling responses to internal and external stimuli.
• The main functions of the nervous system include:
  
  • Sensory Input: The collection of information from sensory receptors throughout the body and relaying it to the brain and spinal cord.
  • Integration: The interpretation and processing of sensory input within the central nervous system.
  • Motor Output: The response generated by the central nervous system and conveyed to muscles or glands to initiate an action.

Basic Structure of the Nervous System

• Neuron: Basic cell of the nervous system.
  • Dendrites: Receive signals.
  • Axon: Carries signals.
• The nervous system is divided into different parts:
  
  1. Central Nervous System (CNS): Responsible for processing and coordinating information. The brain and spinal cord are part of the CNS.
  2. Peripheral Nervous System (PNS): Responsible for transmitting information to and from the CNS.
     
     • Somatic Nervous System (SNS): Controls voluntary movements and transmits sensory information from the body to the Central Nervous System (CNS).
     • Autonomic Nervous System (ANS): Regulates involuntary physiological processes, including heart rate, digestion, respiratory rate, and glandular activity. It operates automatically without conscious control.
       
       • Sympathetic Nervous System: Often referred to as the “fight or flight” system.
       • Parasympathetic Nervous System: Known as the “rest and digest” system.

Muscular System

Basic Functions of the Muscular System

• The muscular system is essential for movement, stability, posture, and heat production.
• The main functions of the muscular system are:
  
  1. Movement: Muscles contract to allow physical movement and mobility.
  2. Stability and Posture: Muscles provide support and help maintain body posture.
  3. Heat Production: Muscles generate heat, which is vital for body temperature regulation.
  4. Circulation: Muscles assist in moving blood and fluids throughout the body.

Basic Structure of the Muscular System

• The muscular system is structured to support movement, stability, and essential bodily functions.
• The main structures of the muscular system are:
  
  • Muscle Tissue Types (3):
    
    • Skeletal: Voluntary. Attached to bones.
    • Smooth: Involuntary. Located in the walls of organs.
    • Cardiac: Involuntary. Located in the heart.
  • Muscle Fibers: Muscle fibers are the long, cylindrical cells that make up muscle tissue and enable contraction.
  • Connective Tissues: Connective tissues provide structure, support, and attachment points within the muscular system.
    • Tendons: Connect muscle to bone.
  • Nervous Connections: The nervous system plays a crucial role in muscle control.

Reproductive System

Female Reproductive System

• The female reproductive system is a system of organs responsible for producing eggs, facilitating fertilization, supporting pregnancy, and giving birth.
• The key structures of the female reproductive system include:
  
  • Ovaries: Located on each side of the uterus, the ovaries are the primary reproductive organs in females. Produce eggs (ova) and the hormones estrogen and progesterone.
  • Fallopian Tubes:  The fallopian tubes connect the ovaries to the uterus and are the site where fertilization usually occurs if sperm is present.
  • Uterus: The uterus is a pear-shaped organ that supports fetal development during pregnancy.
    • Endometrium: Lining of the uterus that thickens for implantation and sheds during menstruation.
  • Cervix: The cervix is the lower part of the uterus that opens into the vagina.
  • Vagina: The vagina is a muscular canal that connects the cervix to the external body.

Male Reproductive System

• The male reproductive system is a group of organs that produce, store, and transport sperm.
• The key structures of the male reproductive system include:
  
  • Testes: The male reproductive glands that produce sperm and testosterone.
  • Scrotum: The pouch of skin that holds the testes outside the body, helping regulate temperature for optimal sperm production.
  • Epididymis: A coiled tube where sperm matures and is stored until ejaculation.
  • Vas Deferens: The duct that transports sperm from the epididymis to the urethra.
  • Accessory Glands:
    
    • Seminal Vesicles: Glands that produce fluid rich in sugars to nourish sperm and form part of the semen.
    • Prostate Gland: A gland that adds a milky fluid to semen, which aids in sperm mobility and longevity.
    • Bulbourethral Glands: Small glands that secrete a fluid to neutralize acidity in the urethra, protecting sperm.
  • Penis: The organ through which sperm and urine exit the body.

Integumentary System

Basic Functions of the Integumentary System

• The integumentary system includes the skin, hair, nails, and glands. The main functions of the integumentary system are:
  
  • Protection: Acting as a physical and chemical barrier against harmful agents.
  • Temperature Regulation: Maintaining body temperature through sweat production and blood flow adjustments.
  • Sensory Perception: Allowing the body to detect and respond to environmental changes.
  • Excretion and Absorption: Aiding in waste removal and limited nutrient absorption.
  • Vitamin D Synthesis: Facilitating the production of vitamin D essential for bone health.

Basic Structure of the Integumentary System

• The main layers and structures of the integumentary system include:
  
  • Epidermis: The epidermis is the thin, outermost layer of the skin that acts as a protective barrier.
  • Dermis: The dermis is the thick, middle layer of skin that provides support and elasticity.
  • Hypodermis: The hypodermis is the deepest layer of the integumentary system, composed mainly of fat and connective tissue.
  • Hair: Hair is made of keratin and grows from follicles in the dermis.
  • Nails: Nails are hard, keratinized structures at the tips of fingers and toes.
  • Glands: Produce oils and sweat to maintain skin health and regulate temperature.

Endocrine System

Basic Functions of the Endocrine System

• The primary functions of the endocrine system are:
  
  1. Regulation of Metabolism and Energy Levels
  2. Growth and Development
  3. Response to Stress and Injury
  4. Blood Sugar Regulation
  5. Reproductive System Regulation
  6. Control of Internal Homeostasis

Basic Structure of the Endocrine System

• The endocrine system consists of specialized glands that produce and release hormones. Key structures include:
  
  1. Hypothalamus: Links the nervous and endocrine systems, controls the pituitary gland.
  2. Pituitary Gland: The “master gland” that regulates other glands and produces growth hormone.
  3. Thyroid Gland: Regulates metabolism and energy levels.
  4. Parathyroid Glands: Regulate calcium levels in the blood.
  5. Adrenal Glands: Help respond to stress and regulate metabolism.
  6. Pancreas: Manages blood sugar balance through insulin and glucagon.
  7. Pineal Gland: Regulates sleep-wake cycles with melatonin.
  8. Reproductive Glands (Ovaries/Testes): Control reproductive functions and character.

Urinary System

Basic Functions of the Urinary System

• The main functions of the urinary system are:
  
  1. Excretion of Wastes and Filtering of Blood
  2. Regulation of Fluid and Electrolyte Balance
  3. Acid-Base Balance

Basic Structure of the Urinary System

• Some of the basic structures of the urinary system include:
  
  1. Kidneys: Two kidneys are situated below the ribs and towards the middle of the back. They are responsible for blood filtration, homeostasis, and production of erythropoietin.
  2. Nephron: Function unit of the kidney. The structure that actually filters blood and forms urine.
  3. Ureters: Narrow tubes that transport urine from the kidneys to the bladder. Ureter muscles propel urine downward. If urine is backed up, it can lead to kidney infections.
  4. Urinary Bladder: A hollow organ located in the lower abdomen that stores urine. Expands to hold urine and contracts to release it via the urethra.
  5. Urethra: The tube that allows urine to exit the body. Different lengths for men (6-8 inches) and women (1.5 inches)

Immune System

Basic Functions of the Immune System

• The immune system is a complex network of cells, tissues, and organs working together to protect the body from harmful pathogens and maintain overall health.
• The main functions of the immune system are:
  
  1. Defense Against Pathogens
  2. Surveillance
  3. Destruction of Pathogens
  4. Regulation of Immune Responses
  5. Memory Formation
  6. Clearance of Dead Cells and Debris
  7. Maintenance of Homeostasis

First Line of Defense

• The body’s first line of defense is innate (non-specific). It consists of:
  
  • Physical Barriers: Consists of the skin and mucous membranes.
  • Chemical Barriers: Consists of saliva, tears, and gastric juice (acidic fluid secreted by stomach).
  • Biological Barriers: Consists of normal flora (beneficial bacteria).

Second Line of Defense

• The body’s second line of defense is also innate (non-specific). It consists of:
  
  1. Inflammatory Response: The body’s immediate reaction to tissue damage or infection. It aims to contain and eliminate the invading pathogens and initiate repair.
  2. Phagocytosis: The process by which certain white blood cells (leukocytes) engulf and digest pathogens and debris.
  3. Complement System: Consists of a series of plasma proteins that work together to enhance the immune response.
  4. Natural Killer Cells: A type of white blood cell that can recognize and kill infected or abnormal cells without prior activation or specific targeting.
  5. Interferons: Signaling proteins released by cells infected by viruses.

Third Line of Defense

• The body’s third line of defense is an adaptive (specific) immune response and targets specific antigens.
• The lymphatic system is integral to the third line of defense and includes various organs and tissues that produce and store immune cells.
  
  • Lymphocytes: The primary immune cells produced and stored in the lymphatic system.
    
    • B Cells: Fights infections by forming antibodies.
    • T Cells: Fights infections by destroying cells infected with viruses.
• Immunity is the body’s ability to resist pathogens and involves two primary types:
  
  • Active Immunity: Memory cells are produced after exposure to a pathogen.
  • Passive Immunity: Results from the transfer of antibodies from an immune individual to a non-immune individual.

Skeletal System

Basic Functions of the Skeletal System

• The skeletal system is crucial for providing structure, protection, and movement. It also plays roles in producing blood cells and storing essential minerals.
• The main functions of the skeletal system are:
  
  1. Support and Structure: Provides the framework for the body.
  2. Protection: Guards vital organs like the brain, heart, and lungs.
  3. Movement: Enables bodily movements through bones and joints.
  4. Blood Cell Production: Produces blood cells in bone marrow.
  5. Mineral Storage: Stores and releases minerals such as calcium and phosphorus.

Basic Structure of the Skeletal System

• The skeletal system consists of two main divisions:
  
  • Axial Skeleton: Forms the central framework of the body, protecting critical organs and providing structural support. The axial skeleton is composed of 80 bones.
  • Appendicular Skeleton: Includes the bones of the limbs and girdles, allowing for movement and interaction with the environment. The appendicular skeleton is composed of 126 bones.
• Some other important structures of the skeletal system include:
  
  • Bones: Hard, dense structures that make up the skeleton.
  • Joints: Where two or more bones meet.
  • Cartilage: Flexible tissue providing cushioning between bones.
  • Ligaments: Strong tissues connecting bones.