Heart, Blood and Immunity

• These notes cover the topics of heart monitoring, coronary heart disease, blood vessels, blood composition, immunity, respiration, and excretion.

Ways to Monitor Heart

• Court pulse rate: Feeling the arteries near the neck or wrist.
• A stethoscope can be used to listen to the closing of heart valves.
• ECGs (electrocardiograms) detect electrical impulses of the heart.
• Average heartbeats at rest are 60-75 bpm.

Coronary Heart Disease (CHD)

• Diets high in fats and cholesterol can cause build-up of fatty plaque in arteries.
• Plaque makes artery walls stiffer and the lumen narrower.
• CHD causes an increase in blood pressure because the artery has to work harder to pump blood.
• If a coronary artery gets blocked, the heart muscles may not get enough oxygen, potentially stopping the heart.

Blood Vessels

Arteries

• Arteries have thick, tough walls with muscles, elastic fibers, and fibrous tissue.
• They carry blood at high pressure.
• Arteries prevent bursting, maintain pressure wave, and prevent backflow of blood.
• Narrow lumen increases as a pulse of blood passes through.
• Arteries do not have valves.

Veins

• Veins have thin walls, mainly fibrous tissue, with little muscle and few elastic fibers.
• They carry blood at low pressure.
• Large lumen reduces resistance to blood flow.
• Valves prevent backflow of blood due to low pressure.

Capillaries

• Capillaries are microscopic and allow diffusion of materials between the capillary and surrounding tissues, such as amino acids, glucose, oxygen, water, fatty acids, and iron.
• Gas exchange is facilitated in capillaries.
• Permeable walls are one-cell thick, with no muscle or elastic tissue.
• The lumen is approximately one red blood cell wide.
• No valves are present in capillaries.
• Blood pressure is lower in capillaries than in arteries.
• Blood cells pass through slowly to allow diffusion of materials and bone fluid.

Coronary Artery

• The coronary artery is responsible for supplying the heart with adequate oxygen and nutrients.

Composition of Blood

• Blood is composed of two main components: plasma and blood cells.

Plasma

• Plasma is composed of 90% water and 10% mixture of nutrients, waste, and hormones.

Blood Cells

• There are three main types of blood cells: red blood cells, white blood cells, and platelets.

Red Blood Cells

• The primary role is to carry and deliver oxygen to cells in the body.
• Red blood cells have a biconcave disc shape and no nucleus.
• They are small and flexible, allowing them to squeeze through narrow capillaries.
• They have an increased surface area for hemoglobin.
• Red blood cells contain hemoglobin, which is an iron-containing pigment.
• Hemoglobin picks up oxygen at the lungs and releases it at tissues.

White Blood Cells

• White blood cells include phagocytes and lymphocytes.
• Phagocytes help remove harmful microorganisms by engulfing them to digest pathogens upon engulfing.
• Phagocytosis is the process of phagocytes consuming pathogens.
• Lymphocytes, some of which remain in the lymph nodes, help to create proteins called antibodies.
• Antibodies recognize different pathogens and quickly eliminate them before harm occurs.
• Antibodies have a Y shape and have cell membranes and nuclei.
• Antibodies bind to pathogens and can neutralize them, signal phagocytes to consume them, or cause pathogens to self-destruct.

Platelets

• Platelets' main function is to form blood clots when injured.
• Platelets are the smallest of the three blood cell types.
• They are usually round, but when activated, produce "limbs" that help with blood clotting.

Blood Clotting

• Blood clotting helps to prevent excessive blood loss.
• Platelets convert fibrinogen (soluble) into fibrin (insoluble).
• Fibrin joins together to form a mesh that helps trap red blood cells.
• The fibrin mesh creates a blood clot that seals the wound while new body cells replace the damaged tissue.

Diseases and Immunity

Pathogens

• Pathogens are microorganisms that invade the body and cause diseases, including viruses.
• A transmissible disease is a disease in which the pathogen can pass from one host to another.
• A host is an organism that harbors pathogens, providing them a space to live and reproduce.
• Pathogens cause disease by producing toxins or damaging surrounding healthy cells and consuming their nutrients.
• Bacteria reproduce by cell division.
• Viruses reproduce by attaching to bacteria or healthy cells, infecting them with viral DNA, and making copies of the viruses until the cell bursts.

Vibrio Cholerae

• Vibrio cholerae (cholera bacteria) produces a toxin in the small intestine.
• The toxin stimulates cells lining the intestines to release chloride ions into the lumen, lowering its water potential.
• Water from cells lining the intestines moves into the lumen by osmosis, resulting in a large quantity of water lost from the body in watery feces.

Transmission

• Transmission is the moving of a disease from an infected person or a host to an uninfected person.
• Direct transmission includes transfer through body fluids or unprotected sex.
• Indirect transmission occurs when the pathogen leaves the host and is carried to an uninfected individual, such as through water droplets in the air or insect bites.

Immunity and Disease: Methods of Defense

• Mechanical barriers: Many bacteria live on the epidermis of the skin. If there is a wound, they can enter. Noschair filters to trap the microbes.
• Chemical barriers: Acidic conditions and moist linings in passages contain enzymes to dissolve the cell walls of bacteria.
• White blood cells: Lymphocytes produce antibodies. Phagocytes engulf pathogens to digest it.
• Immunity: your body builds up defense against pathogens.

Active Immunity

• Defense against a pathogen by antibodies production in the body, and long-term memory cells are produced
• Gained after an infection by pathogen and recovering from it through vaccination

Natural Active

• Body gets infected by pathogens, triggering immune responses and triggers memory cells to recognize pathogens

Artificial Active Immunity (Vaccination)

• Involves a harmless form of pathogens and produces lymphocytes that respond.

Passive Immunity

• Abtain antibodies made by another organism and no memory cells produced.

Respiration

• Uses of energy in humans: The contraction of muscle cells, Production of new chemicals, body temperature, Active transport of materials, chemical production and transmitting nerve impulses.
• Aerobic respiration: Energy is released in the presence of oxygen. C6H12O6 + 6O2 -> 6CO2 + 6H2O
• Anaerobic respiration (animals): Leads to muscle cramps when heart and lungs cant supply quickly to muscles. GLucose -> lactic acid + energy.
• Aerobic repiration in plants produces the most O2.

Aerobic Respiration chemical formula:

• C6H12O6 + 6O2 → 6CO2 + 6H2O + ATP

Anaerobic respiration (animals)

• C6H12O6 → 2C3H6O3 + 2ATP
• Glucose → lactic acid + energy (ATP)
• Can lead to muscle cramp.
• Muscle cells respire aerobically for short periods but when heart & lungs are unable to supply oxygen

How to test for presence of CO2

• If it is present, limewater presents itself with a cloudy grey color.

Anaerobic respiration

• C6H12O6(aq) → 2C2H5OH(aq) + 2CO2(aq) + ATP .
• Increase temp increases speed and glucose concentrations.

Oxygen Debt

• Oxygen debt: refers to the situation where your heart and lungs don't provide enough oxygen and can't keep up.
• during vigorous, exercise not enough oxgygen os produced
• After excessice, body needs to move lactic acid.
• both are cellular respiration

Differences

• Aerobic has oxygen, CO2 and H20 and 38 ATP, and happens in mitochondria
• Anaerobic does not contain oxygen, has ehtanol, co2 & ATP & more, has 2 ATP, this process occurs in the lungs.
• Cartilage allows for airways to be open and preventing collapsing
• Cilliated cals and Gobblet cells are importatn for infection and damage.

Adaptions of Alveoli

• Good amount of surface area for gas, molst epethilial, diffusion.

Excreation

• Is important in our body.
• Metabolic and undigested food are waste products
• egestion = expel
• excreation = made by the body of metaolic reactions.

Organ Functions

• Liver = breaks down acids
• Lungs - get rid of CO2 and Water in exhiliation
• Skin causes a lost of warer salt and urea.

Liver

• Ascimilation of amino acids
• converting into urea

Kidney

• expels the toxic waste.