Biology II Lecture II

Two types of digestive tracts

Incomplete or complete

Two types of feeding styles

• Continuous

• Discontinuous

Dentition (tooth types) varies with

diet

Which types of digestive tracts and feeding styles is more complex

• Complete is more complex than incomplete

• Discontinuous is more complex that continous

Incomplete digestive tracts

• Incomplete tract has a single opening

• Planarian – flat worm

• Food enters through mouth and muscular pharynx

• Tracts and branches travel through body

• Wastes exit through mouth and muscular pharynx

• Lacks specialized parts

• Diffusion is sufficient to distribute molecules

Complete digestive tracts

• Complete Tract has two openings

• Earthworm

• Food enters through mouth

• Travels through specialized parts

  • Pharynx, esophagus, crop, gizzard

  • Typhlosole fold in digestive tract increases surface area

• Wastes exit through anus

Continuous feeding styles

• Filter feeders

• Do not need food storage area because continually feeding

• Clams, baleen whales

• Always have water moving into the mantle cavity via incurrent siphon

• Particles deposited on gill

Discontinuous feeding styles

• Food storage area needed because of intermittent capture of food particles

• Squid

• Uses tentacles to seize prey

• Allows the beaklike jaws to pull pieces into the mouth with the radula

Dentition in omnivores

• Variety of specializations

• Accommodate both vegetation and meat

• Humans have 32 teeth

  -2 incisors, 1 canine, 2 premolar, 3 molars (8) on half (right or left) of jaw

  -16 total (bottom or top) = 32

Dentition in Herbivores

• Incisors for clipping

• Premolars and molars for grinding

• Eat plants

Dentition in Carnivores

• Pointed incisors and enlarged canines

• Shear off pieces small enough to swallow

• Eat meat

• Teeth for shearing

Example of omnivores

humans

Example of herbivores and its teeth

• horses

• Reduced canines

• sharp incisors

• large, flat molars and premolars

examples of carnivores

• Dolphins

  • similarly shaped conical teeth

• Lions

  • pointed incisors

  • enlarged canines

  • jagged molars and premolars

Human Digestive Tract

• Human digestive tract is complete

  • 2 openings

• Part of a tube-within-a-tube body plan

• Begins with a mouth and ends in an anus

• Digestion entirely extracellular (outside tissue)

  • Digestive enzymes are secreted by:

  • wall of the digestive tract, or nearby glands

Which organs don’t touch food

• Salivary glands

• Liver

• Gallbladder

• Pancreas

Two stages of human digestion

1. Mechanical:

   • Chewing to mix with saliva

   • Churning in stomach to mix food and digestive juices

2. Chemical:

   • Action of enzyme to break down food into usable, absorbable molecules

   • Enzymes are specific to certain molecule

four digestive layer and explanations

• Mucosa

  • Innermost layer

  • Produce mucus to protect lining

• Submucosa

  • blood vessels

  • lymphatic vessels

  • nerves

• Muscularis

  • Layers of smooth muscles

  • contract to move food

• Serosa

  • Outermost layer

  • Keeps digestive organs externally lubricated

Order of human digestive tract

Mouth » salivary glands » pharynx » swallowing » esophagus » sphincter » stomach » chyme » small intestine » duodenum » pancreas » liver » gallbladder » large intestine » rectum » anus

4 orders in digetsive system

1. Ingestion

2. Digestion

3. absorption

4. elimination

Mouth in human digestive tract

• Mouth: start of tract

• Three major pairs of salivary glands

  • Saliva contains salivary amylase

  • Salivary amylase initiates starch digestion

• Tongue is composed of striated muscle

  • Mixes chewed food with saliva

  • Forms mixture into bolos

• Mastication: chewing

• teeth chew food; tongue tastes and pushes food for chewing and swallowing

Pharynx in human digestive tract

• passageway where food is swallowed

• Where digestive and respiratory passages come together then separate

• Soft palate closes off nasopharynx when swallowing

• Epiglottis

• Covers glottis: opening into trachea

• Keeps food from air passages (most of the time)

Swallowing

1. Closing nasopharynx to prevent food from entering the nasal passages

2. Closing the glottis via epiglottis to prevent food bolus entering the trachea

what is this an image of

Pharynx

Esophagus in human digestive tract

• Takes food to stomach by peristalsis

• Peristalsis is wavelike contractions that push food bolus along

Stomach in human digestive tract

• Contracts vigorously to mix food and digestive juices

• Stomach wall has deep folds called rugae

• Folds disappear as the stomach fills to an approximate volume of one liter

• Thick mucous coating protects from acid

• secretes acid and digestive enzyme for protein; churns, mixing food with secretions, and sends chyme to small intestine

Lining in stomach of human digestive tract

• Epithelial lining of the stomach has millions of gastric pits, which drain gastric glands

• Pepsin is a hydrolytic enzyme that acts on proteins to produce peptides

• HCl digests food and kills most bacteria

Other parts in stomach pathway of human digestive tract

• Food mixing with gastric juices becomes chyme

• Junction between stomach and small intestine controlled by a sphincter

• Sphincter is a circular band of muscle that surrounds a tube and acts as a valve

• When the sphincter relaxes, a small quantity of chyme passes into the small intestine

• Chyme triggers neural response that closes the sphincter

• Takes time for sphincter to relax again before allowing more chyme to enter

• This time delay controls rate and completeness of digestion

Small intestine in human digestive tract

• mixes chyme with digestive enzymes for final breakdown; absorbs nutrient molecules into body; secretes digestive hormones into blood

• Small in diameter but very long (6m, 18ft)

• First segment is duodenum

  • Chyme from stomach enters the duodenum and is neutralized by NaHCO3

  • Absorbs 95% of water from food

  • Mixes with secretions from the liver and pancreas

• Epithelial cells in intestine also produce enzymes

• Liver, pancreas and intestinal enzymes complete digestion of peptides and sugars

Membranes in small intestine of human digestive tract

• Mucous membrane of small intestine

  • Has ridges and furrows that give it a corrugated surface

  • Villi are ridges on the surface, which contain even smaller ridges, microvilli

  • Greatly increases absorptive area

  • Each villus contains blood capillaries and a lymphatic capillary (lacteal)

  • Microvilli appear fuzzy – brush border –secrete enzymes too

Accessory organs of human digestive tract

• Accessory organs contribute to digestion but don’t “touch” food

• Liver, pancreas, gall bladder

• Produce products that aid in digestion

  • enzymes, hormones

• Empty into duodenum of small intestine

Pancreas

• Elongated flattened organ

• Both endocrine and exocrine functions, focus on exocrine for digestion

• produces pancreatic juice: contains digestive enzymes, and sends it to the small intestine; produces insulin and secretes it into the blood after eating

• Produces pancreatic juices

  • Contain NaHCO3 that neutralizes chyme

  • Produces other enzymes amylase, trypsin, lipase

Liver

• Large gland

• 100,000 lobules that are the structural and functional units of liver

• Between lobules are the:

  1. Bile duct:

     • takes bile away from liver

  2. Hepatic artery:

     • brings oxygen to liver

  3. Hepatic vein:

     • transports nutrients from intestines

Functions of the liver

• major metabolic organ: processes and stores nutrients; produces bile for emulsification of fats

• Detoxify blood by removing and metabolizing poisonous substances

• Stores iron and vitamins A, B12, D, E, and K

• Makes plasma proteins from amino acids

• Stores glucose as glycogen after a meal,

• Breaks down glycogen into glucose to maintain glucose levels in blood

• Produces urea after breaking down amino acids

• Removes bilirubin and excretes it in bile

• Regulates blood cholesterol levels
  

Gallbladder

• Pear shape sac under the liver

• Stores excess bile from liver and sends it to small intestine

• Released as needed into duodenum

• Cholesterol portion of bile can come out of solution and form gall stones

  • Can block duct and are removed surgically

Large intestine in human digestive tract

• Includes cecum, colon, rectum, and anal canal

• Cecum:

  • “Dead end” below the point that
    the small intestine enters

  • Has small projection: appendix

• Colon subdivided into ascending, transverse, descending, and sigmoid colon

• Larger in diameter, but shorter in length than small intestine: 1.5m 4.5 ft

• Absorbs water, salts, and some vitamins to produce feces

• No “human” digestion in Large Intestine

• Contains bacteria that breakdown indigestible material

Reactum

stores and regulates elimination of feces

Digestion and absorption of nutrients

• Nutrients (biomolecules) are digested by specific enzymes and the products enter the blood stream

• Most nutrients are taken to the liver to be further processed and dispersed or stored

• Fats are absorbed by lacteals: vessels of the lymphatic system

• Involves, carbohydrates, lipids, and proteins

Digestion of Carbohydrates

• Digestion begins in the mouth with salivary amylase

• Enzymes from the pancreas (pancreatic amylase)and lining of small intestine (maltase) continue digestion

• Carbohydrates are broken down into individual monomers and eventually glucose

• Glucose is transported to the liver for use or storage as glycogen

3 carbohydrate digestion including enzyme and location

• Starch and water:

  • »broken by salivary amylase in mouth»Maltose

• Starch and water:

  • »» broken by Pancreatic amylase in pancreas»maltose

• Maltose an water:

  • »»»broken by maltase in small intestine»> glucose+ glucose

Nutrient absorption of carbohydrates

• Carbohydrates are present in food in the form of sugars, starch, and fiber.

• Fruits, vegetables, milk, and honey are natural sources of sugars.

• After being absorbed from the digestive tract all sugars are converted to glucose

  • Glucose is the preferred direct energy source in cells.

• Animals store glucose as glycogen (in liver)

• Plants store glucose as starch (Ex. potato)

Nutrient absorption of carbohydrate fibers

• Includes various indigestible carbohydrates derived from plants

• Food sources rich in fiber include beans, peas, nuts, fruits, and vegetables

• Technically, fiber is not a nutrient for humans

  • Cannot be digested

  • Soluble fiber combines with bile acids and cholesterol in the small intestine and prevent them from being absorbed

Digestion of proteins

• Digestion begins in the stomach

• Enzymes from stomach (pepsin) break proteins into
  peptides

• Additional enzymes from the pancreas (trypsin) further digest protein into peptides

• Peptides are digested into amino acids by enzymes (peptidases) from the small intestine

3 protein digestions including enzymes and location

• Protein and water:

  • broken down by Pepsin in stomach »»peptides

• Protein and water:

  • Broken down by trypsin in pancreas»peptides

• Peptides and water:

  • Broken down by peptidases in small intestine»» amino acids

Nutrient absorption of Proteins

• Adequate protein formation by the body requires 20 different types of amino acids

• 9 essential amino acids

  • Essential amino acids from the diet

  • Some foods, such as meat, milk, and eggs, provide all 20 (complete)

  • Vegetables supply one or more essential amino acids, but are deficient in at least one of the 9

  • Vegetarians should combine plant products to
    provide all the essential amino acids

Digestion of lipids

• Digestion begins in the small intestine

• Bile salts from the liver break fat into fat droplets

• Enzymes from pancreas (lipase) digests fat molecules in the form of droplets

• Fat droplets are broken into glycerol (monoglycerides) and fatty acids

• These products are reformed into chylomicrons and enter lacteals

3 Digestions of lipids including enzymes and location

• fat

  • broken down by bile salts in liver»»fat droplets

• fat and water

  • broken down by lipase in small intestine»» glycerol + 3 fatty acids

Nutrient absorption of lipids

• Lipids include: Fat, oils, and cholesterol

• Saturated fats (solids at room temperature) usually
  come from animals

  • Exceptions are palm oil and coconut oil

  • Butter and meats, such as marbled red meats and bacon, contain saturated fats

• Unsaturated fats come from plants

• Cholesterol is a lipid, not found in plants, that the body uses to make other compounds

Minerals

• 20 minerals needed for physiological functions

• Include - Iron, calcium, magnesium, zinc, sodium

• Help to regulate biochemical reactions, maintain fluid balance, and are involved in forming other compound

what organisms use each type continuous and discontinuous and why

• Organisms such as clams and baleen whales have continuous feeding system since they are filter feeders that are constantly eating.

• Organisms such as squids have a discontinuous feeding system because they have a food storage where food can be stored within body.

Difference in dentition in mammals

• Omnivores have teeth that accommodate vegetables and plants.

• Herbivores have incisors for clipping plants and premolars and molars for grinding.

• Carnivores have pointed incisors and enlarged canines to sheer off meat pieces small enough to swallow.  

What are the two types of digestion and where do they occur

• The mechanical digestion occurs in the mouth where food is chewed and churning in the stomach to mix food and digestive juices.

• Chemical digestion occurs where enzymes breakdown food into usable, absorbable molecules

What molecule types (starch, lipid, protein etc) are digested in each section

• Mouth: carbohydrates, starch

• pancreas: Starch, protein

• Stomach: proteins

• Small intestine: maltose, peptides, lipids

• Large intestines: water, salt, vitamins

• Liver: Fat

What foods contain those molecules? What are vitamins, minerals, amino acids?

• Carbohydrates are in foods such as fruits, vegetables, milk, and honey.

• Carbohydrates also contains fiber, which can be found in beans, peas, nuts, fruits, and vegetables.

• Proteins can be found in meat, milk, vegetables, and eggs.

• Lipids cab be found in meat and butter.

• Vitamins are organic compounds the body is unable to produce but are required for metabolic purposes.

• Minerals are 20 nutrients that are needed for physiological functions. It includes iron, calcium, manegsium, zinc, and sodium.

• Amino acids are molecules that make protiens

What enzymes are involved in digestion? Where are those enzymes produced and introduced and what is the end product of their action

• Salivary amylase: breaks down starch and water in mouth to produce maltose

• Pancreatic amylase: breaks down starch and water in pancreas to produce maltose

• Maltase: Breaks down maltose and water in small intestine to produce glucose

• Pepsin: Breaks down proteins and water in stomach to produce peptides

• Trypsin: Breaks down proteins and water in pancreas to produce peptides

• peptidases: Breaks down peptide and water in small intestines to produce amino acids

What does the circulatory system use fluids to do

• Transport oxygen and nutrients to the cells

• Removing waste

The method of transport in the circulatory stem depend on what?

the body plan of the animal

What are the 2 classifications of animals

• invertebrate (no backbone)

• vertebrae

Circulatory system in invertebrates

• Some invertebrates have NO circulatory system

  • Body plan makes a circulatory system unnecessary.

• Hydras, flatworms

  • Thin, flat bodies

  • Gastrovascular cavity contacts all cells

    • Allows for exchange of gases and wastes through diffusion

• Coelomates (sea stars)

  • Coelomic fluid distributes oxygen and picks up waste via DIFFUISON

Invertebrates with a Circulatory System

• Most invertebrates have a circulatory system

• The fluid circulated varies depending on the type of
  circulatory system

• Two types of circulatory fluids:

  • Blood (Always contained within blood vessels)

  • Hemolymph (Mixture of blood and tissue fluid flows from vessels into a body cavity called a hemocoel)

• Two types of circulatory systems in invertebrates

  • Open and Closed

Open circulatory system in invertebrates

• Uses hemolymph

• Blood vessels plus open spaces

  • Heart pumps hemolymph via vessels

  • Vessels empty into open tissue spaces

  • Hemolymph eventually drains back into heart

Examples of invertebrates that use an open circulator system; explain

Grasshopper: heart ostia close during contraction and open when relaxed to create a flow of hemolymph

Closed circulatory system in invertebrates

• Uses blood in vessels

• Heart pumps blood to capillaries

  • Valves prevent back flow of blood

  • Gases and materials diffuse across capillaries

  • Vessels bring fluid containing waste from cells back to the heart

Examples of invertebrates that use a closed circulator system; explain

Earthworm: five hearts pump blood into ventral vessel that branches into lateral vessel in each body segment

Circulatory system in vertebrates

• All vertebrates have a closed circulatory system

  • Cardiovascular system

  • Heart and vessels

• Vertebrate hearts have common features:

  • Atrial chamber(s) of heart

  • Receive blood from general circulation

  • Ventricle chamber(s) of heart

    • Pump blood out through blood vessels

• Three kinds of vertebrate vessels

  1. Arteries 2. Veins 3. Capillaries

Vertebrate vessel: blood pathway from heart

• Circulation pathway varies by animal

• Arteries: Carry blood away from heart

• Arterioles: Lead to capillaries

• Capillaries: Exchange materials with tissue fluid

• Venules : Lead to veins

• Veins: Return blood to heart

Layers of arteries and veins in vertebrates

• Outer layer is fibrous connective tissue that is
  rich in elastic and collagen fibers.

• Middle layer is smooth muscle and elastic tissue

• Inner layer is the endothelium

Arteries in vertebrate vessels

• Arteries have thick walls

• Those attached to heart expand easily with each contraction

• Thicker middle muscle layer than veins

  • contract to push blood through the system

• Arterioles

  • Small arteries

  • Diameter regulated by nervous system

  • Contraction and dilation effects blood pressure

Capillaries in vertebrate vessels

• Narrow microscopic tubes

• One cell layer thick

• Thin walls

  • allow for exchange of nutrients and waste with cells

• Red blood cells travel through one at a time

• Can open and close in response to blood flow needs

Veins in vertebrate vessels

• Collect blood from the capillaries and take it back to the heart

• Venules

  • Drain capillaries

  • Join to form veins

• Veins

  • Thinner walls than artery

  • Valves open towards heart to prevent back flow

The two types of circulatory pathways in vertebrates

1. One circuit (single loop)

   • single atrium

   • single ventricle

2. Two Circuit (double loop)

   • Two atria

   • One or two ventricle

   • heart pumps blood tissue in systematic loop

   • heart pumps blood to lungs in pulmonary circuit

Single loop circuit in vertebrates circulatory pathway

• Heart has one atrium and one ventricle

• Ventricle sends oxygen poor blood to gills

• Oxygen is picked up at gills and sent through body

• Body capillaries receive oxygen rich blood

• Blood returns to atrium then ventricle then back to gills

• Blood is under reduce pressure after leaving gills

• Ex: Fish

Double loop amphibians (2 circuits) in vertebrates circulatory pathway

• Systemic (blood to tissue)

• Pulmonary (blood to lungs)

• Adaptation to breathing on land

• Two atria with single ventricle

• Oxygen poor blood enters right atrium

• Oxygen rich blood enters left atrium

• Both atrium empty into single ventricle

• Oxygen rich blood is pumped into systemic circuit

Double loop- 4 chambers in vertebrates circulatory pathway

• Two atria, two ventricles

• Right ventricle pumps to the lungs

• Left ventricle (larger more muscular)
  pumps to the body

• Results in adequate pressure in both circuits

• Birds, mammals and crocodiles have 4 true chambers

• Most reptiles have a partially divided ventricle but little mixing of blood

Human Cardiovascular System overview

• Closed, two circuit cardiovascular system

• Pumping heart keeps blood flowing in arteries

• skeletal muscle contractions keeps blood moving in veins

Characteristics of the human Heart

• Cone-shaped

• Fist-sized

• Very muscular organ

• Lies within a fluid-filled sac

  • Pericardium

• Majority of heart is cardiac muscle called myocardium

• Nourished by coronary artery and cardiac vein

• Internal septum separates heart into left & right halves

Chambers of the human heart

• Each half has two chambers

  1. Upper two chambers are atria

     • Have wrinkled appendages called auricles

     • Thin-walled

     • Receive blood from circulation

  2. Lower two chambers are ventricles

     • Thick walled

     • Pump blood away from heart

Four valves of the human heart

• Contains four valves to direct flow of blood and prevent backward movement

  1. Atrioventricular Valves

     • Between atria and ventricles

     • Supported by chordae tendineae

     • Prevent inversion

     • Right side: tricuspid

     • Left side: bicuspid

  2. Semilunar Valves

     • Between ventricles and vessels

     • Pulmonary: right ventricle and pulmonary trunk

     • Aortic: left ventricle and aorta

Label the picture

Exterior

Label the picture

Interior

Path of Blood through Human Heart

• Blood returning to heart from body enters

1. Superior & inferior vena cava

2. Right atrium

3. tricuspid valve

4. Right ventricle

5. Semilunar pulmonary valve

6. Pulmonary arteries

• Blood returning to heart from lungs enters

7. Pulmonary veins

8. Left atrium

9. Bicuspid (mitral) valve

10. left ventricle

11. Semilunar aortic valve

12. Aorta

Heartbeat

• Beats about 70 times a minute, 2.5 billion times in a lifetime, each beat is less than a second

• Each heart beat, or cardiac cycle, is a pattern of contraction and relaxation of the heart

• Systole: Contraction of heart chambers

• Diastole: relaxation of heart chambers

• Patter of contraction (Cardiac Cycle)

• Sound of heartbeat is valves closing

Systole and diastoel in a heartbeat

• Atria contract (systole) while ventricles are relaxed (in diastole)

  • Pushes blood through tricuspid and bicuspid valves
    into relaxed ventricles (diastole)

  • Ventricles fill due to atrial contraction

  • Only takes 0.15 sec because of short distance

• Ventricles contract (systole) while atria relax (systole)

  • Time is 0.30 sec because blood is moving further

• Blood enters pulmonary artery and aorta due to
  ventricular relaxation, then ventricles relax

Timing of atria and ventricle

• 0.15 sec: systole (contract) atria and diastole (relax) ventricle

• 0.30 sec: Diastole (relax) atria and systole (contract) ventricle

• 0.40 sec: Diastole (relax) atria and ventricle

Blood Pressure in Arteries

• Heart supplies pressure that keeps blood moving in the arteries

  • Systolic Pressure

    • Pressure in the arteries during ventricular systole

  • Diastolic Pressure

    • Pressure in the arteries during ventricular diastole

How is blood pressure measured in arteries

• Measured with a sphygmomanometer (sfig-mo-mon-om-it-er) on the brachial artery

• Expressed in the form: Systolic “over” Diastolic

Blood pressure in veins; how it gets back to the heart

• Pressure in veins is too low by itself

• Three factors of venous return

  1. Skeletal contraction:push blood past open valve

  2. Vein valves close to prevent back flow

  3. Respiratory pump when we breathe

Blood functions in homeostasis

1. Transport gases, nutrients, waste products and hormones throughout the body

2. Helps destroy pathogenic microorganisms

3. Distributes antibodies that are important in immunity

4. Aids in maintaining water balance and body pH

5. Helps regulate body temperature

6. Carries platelets and factors to form clots to prevent blood/fluid loss

Two major components of blood

1. Plasma

2. Formed elements

Plasma in blood components

• Liquid portion of blood

• Mostly water

• Salts, nutrients, wastes, proteins

• Buffers blood to keep pH stable and maintain osmotic gradient for nutrient flow

Functions of the components in plasma

• Contains:

  • Water: maintains blood volume; transports molecules

  • Plasma proteins: maintain blood osmotic pressure and PH

    • Globulin: transports; fights infections

    • Fibrinogen: blood clotting

  • Salts: maintain blood osmotic pressure and PH; aids metabolism

  • Gases (O2 and CO2): cellular respiration

  • Nutrients (lipids, glucose, amino acids): food for cells

  • Wastes (urea and uric acid): End product of metabolism; excretion by kidneys

  • Hormones: aid metabolism

Three components in Formed elements in blood

• Red blood cells (erythrocytes)

• White blood cells (leukocytes)

• Platelets (thrombocytes)

RBC in formed elements in blood

• Known as erythrocytes

• Small, biconcave disks - dip in on both sides

• Transport O2 and help transport CO2

• Lack a nucleus and contain hemoglobin

  • Four globin protein chains with an iron-containing heme

  • Oxygen binds loosely to the iron = transport of oxygen

    • Manufactured in bone marrow of skull, ribs, vertebrae, and ends of bones

    • Erythropoetin (from kidneys) stimulates production

    • Life span of about 120 days

WBC in formed elements in blood

• Larger than red blood cells

• Contain a nucleus and lack hemoglobin

• Helps fights infections and “foreign” invaders

• When stained, can categorize

categorization of Granular WBC with lobed nucleus and functions

1. Neutrophils (slightly pink): Enter tissues and phagocytize (eat) foreign material

2. Eosinophils (red): Fights parasitic worms

3. Basophils (deep blue): Least common, contains histamines

categorization of Agranular WBC with circular or indented nucleus and functions

1. Monocytes: migrate to chronic infections and turn into macrophages; Phagocytize invaders and send out signals to initiate immune response

2. Lymphocytes: Contains T cells and B cells

   • T cells attack viral infected cells and help activiate immune responses

   • B cells interact with antigens to produce antibodies

   • Antibodies combine with antigens; then phagocytized

Platelets in formed elements of blood

• Result from fragmentation of megakaryocytes

• Involved in coagulation (blood clotting)

What does blood clotting consist of and its process

• Platelets

• RBC

• All entangled within fibrin threads

• When Blood vessels are punctured, platelets congregate and form a plug. The fibrin threads form and trap RBC

Antigens in blood cells

• Blood cells have antigens on their surface membranes

  • Antigens trigger an immune response

    • Antigens on RBC membrane can be

    • A, B or none O and Rh factor (+ or -)

• Presence or absence of antigen determines blood type

  • Type A blood has A antigen on the RBC membrane

Antibodies in blood types

• Antibodies to antigens not on a persons own RBC’s are found in a person’s plasma

  • These are called anti-A or anti-B

  • Blood Type A will have anti-B

• Cross-reactions occur if antigens and antibodies match