Air as a mixture of gases comprises 78% of air ✓ not involved in geological or biological processes in its gaseous form

Air as a mixture of gases comprises 21% of air ✓ Required by aerobic organisms for respiration

Air as a mixture of gases ✓ Is a by product of animal respiration and burning of fuel ✓ Concentration in air varies

Gas exchange in bioenergetics of animals Takes in oxygen (___) • ¹ acts as final electron acceptor in the electron transport chain (ETC) of aerobic animals to produce ATP Releases ___, a by product of aerobic metabolism in the animal’s cells

Challenges Among Multicellular Animals • Undergo increase in size, increased activity and complexity • Except for sponges, cnidarians and flatworms most ___ animals require a system to transport/ circulate gases, nutrients and wastes

Challenges Among Multicellular Animals Invertebrates ___ and ___ use diffusion to acquire water, oxygen and nutrients, and excrete wastes

Challenges Among Multicellular Animals Invertebrates ____ and ____ use diffusion through their epidermis and gastrovascular cavities to exchange water and gases, and to excrete waste products

Challenges among Multicellular animals ___ • Have no true tissues and organs • Excretion and respiration are through diffusion • Nutrients are acquired through diffusion

Challenges Among Multicellular Animals ___ • Have no excretory or respiratory systems • Use diffusion to exchange water and gases, and to excrete waste materials

Challenges Among Multicellular Animals ___ • Do not have circulatory and respiratory systems • Gas exchange is through diffusion in the tegument

Internal Fluids in Animals

Internal Fluids in Animals • Present in animals with closed system (i.e. vertebrates, annelids and a few invertebrates) • Consists of plasma and interstitial/tissue/ intercellular fluid

Internal Fluids in Animals • Found inside the cell • Principal component of the cytoplasm

Open Circulatory system • ___, the circulating fluid or “blood”, is pumped through blood vessels into a (hemocoel) or body cavity • ¹ is returned to blood vessels through pores called (ostia)

Arthropods and most molluscs

Closed circulatory system ___ is confined in vessels and does not mix with interstitial fluid • (Heart) pumps blood in a unidirectional manner to a network of blood vessels (arteries, capillaries, and veins) before blood is returned back to the heart

nemerteans, annelids, cephalopods and vertebrates

• Advantageous to large animals • Allows blood to rapidly deliver oxygen and nutrients to cells and tissues • Allows blood to rapidly remove carbon dioxide and waste products (metabolites) from cells and tissues for excretion • Flow is adjusted to metabolic activity of the organ or tissue

Closed Circulatory system ___ • Circulatory system closed and segmentally arranged • Respiratory pigments (i.e. haemoglobin, hemerythrin or chlorocruorin) often present

Closed Circulatory system ____ • With ventral heart • With dorsal and ventral blood vessels

Fish Circulatory system Heart has ___ atrium/atria and ___ ventricle

Fish Circulatory system ___ collects deoxygenated blood from the sinus venosus ___ receives deoxygenated blood from atrium and pumps this to ventral aorta ___ transports blood to ___ where it is oxygenated Oxygenated blood is then transported to the rest of the body

Double Circulation • For reptiles, birds and mammals - deoxygenated blood flows from the heart to the lungs where it is oxygenated and oxygenated blood is returned back to the heart • For amphibians - deoxygenated blood flows through the pulmocutaneous circuit (through the lungs and skin)

Double Circulation • Oxygenated blood is transported to all parts of the body

Amphibian Circulatory system Amphibian heart has ___ atrium/atria and ___ ventricle

Amphibian Circulatory system • ___ receive (oxygenated blood) from the lungs and (deoxygenated blood) from systemic circulation • Blood from the atria is pumped to the ___ • ¹ has a ridge that pushes (a) oxygen-rich blood to ___ and (b) deoxygenated blood to the ___ • ³ allows gas exchange in the lungs as well as in the skin

Reptilian Circulatory system non-crocodilian reptiles have ___-chambered heart

Reptilian Circulatory system • ___ receives deoxygenated blood from systemic circulation • ___ receives oxygenated blood from lungs • (Ventricle) has three cavities: (cavum venosum, cavum arteriosum and cavum pulmonale ) ✓ Cavities are separated by (muscular ridge and ventral ridge) ✓ Ventricle is effectively divided by a (septum) to reduce mixing of oxygenated and deoxygenated blood

Reptilian Circulatory system ___ divides cavum pulmonale and cavum venosum ___ divides cavum venosum and cavum arteriosum

Reptilian Circulatory system ✓ (Blood from the right atrium) enters the cavum venosum to the cavum pulmonale ✓ (Cavum pulmonale) directs blood to the lungs for exchange of gases (____) ✓ (Oxygenated blood) from the lungs enters the left atrium to the cavum arteriosum to the cavum venosum and will be pumped to the ____

Crocodilian Circulatory system Crocodiles, alligators and caimans are the only reptiles with ____-chambered heart comparable to mammals

Crocodilian Circulatory system • With two aorta where the ___ arising from the ___ and ___ arising from the ___ Two aorta are connected by (foramen of Panizza), which allows blood to bypass the pulmonary circulation when necessary

Avian circulatory system with ___-chambered heart

Avian circulatory system • The two atria and two ventricles are completely separate, which allows complete separation of oxygenated and deoxygenated blood • ___ receives deoxygenated blood and pumps this to right ventricle • ___ pumps blood to the lungs (pulmonary circulation) • ___ receives oxygenated blood from the lungs and pumps this to left ventricle • ___ pumps blood to all parts of the body (systemic circulation) • Birds have larger heart relative to body size and mass to meet high metabolic demands.

Mammalian circulatory system have __-chambered heart

Mammalian circulatory system • Two atria and two ventricles are completely separate, which allows complete separation of oxygenated and deoxygenated blood • Mammals are warm-blooded animals • ___ receives deoxygenated blood and pumps this to right ventricle, which pumps blood to the lungs (pulmonary circulation) • ___ receives oxygenated blood from the lungs and pumps this to left ventricle, which pumps blood to all parts of the body (systemic circulation)

Mammalian heart • Anatomically and functionally divided into (right heart) and (left heart) • (Deoxygenated blood) from all parts of the body are carried by the superior and inferior vena cavae to the ¹ • ___ is separated from the ² by (tricuspid valve), which prevents back flow of blood • ___ pumps blood to the pulmonary artery to the lungs where exchange of gases occur

Mammalian heart • ___ transport oxygenated blood from lungs to the left atrium • The left atrium is separated from the left ventricle by (bicuspid or mitral valve) • (Oxygenated blood) in the left atrium is pushed to the ____, which pushes blood to distributing arteries to all organs of the body ✓ O2, nutrients, minerals, and hormones in blood diffuse to surrounding tissues at the capillary level ✓ Metabolic wastes and CO2 diffuse from surrounding tissues to the blood at the venular level of the capillary

Blood Vessels • Transport blood from the heart to all parts of the body • Largest artery is the aorta • Carry oxygenated blood except the pulmonary artery

Blood Vessels •Site of exchange of gases, nutrients, metabolic wastes between the blood and surrounding tissues

Blood vessels •Transport blood from all parts of the body back to the heart •Transport deoxygenated blood except for pulmonary veins that carry oxygenated blood

Blood Vessels ___ diffuses down its concentration gradient (net movement is out of blood to surrounding tissues) ___ diffuses down its concentration gradient (from surrounding tissues into blood)

Blood Vessels ✓higher at the arteriolar end ✓pushes fluid out of the capillary while keeping blood cells and blood proteins inside blood vessels

Blood vessels • Generated by the protein (albumin ) • Higher at the venular end of the capillary • Brings excess fluid in surrounding tissues back to the blood

___ Conduction system Refers to collection of nodes and specialized conduction cells that initiate and coordinate myocardial (heart muscle) contraction

Cardiac Conduction system • Pacemaker located at the right atrium (RA) • Generates electrical impulses that initiate contraction of the RA followed by the left atrium (LA) • Rate at which it generates impulses is influenced by the sympathetic and parasympathetic divisions of the autonomic nervous system (ANS)

Cardiac Conduction system • Located between the atria and ventricles • Receives impulses from the SA node

Cardiac Conduction system • Located along the inter ventricular septum • Receives electrical impulses from the AV node • Divides into right and left bundle branches

Cardiac Conduction system • Found along the walls of the right and left ventricles • Spread electrical impulses to the walls of the right and left ventricles causing these to contract

Cardiac cycle

Cardiac Cycle • Main purpose of the heart is to pump blood to all parts of the body ✓ Coordinated contraction and relaxation of the heart leading to emptying and filling of the heart, respectively ✓ Each cardiac cycle has ___ (contraction) and ___ (relaxation) ✓ Systole pushes blood out of the heart while diastole allows filling of heart chambers with blood

Cardiac cycle • All four chambers are relaxed • Blood fills the heart

Cardiac cycle • Right and left atria contract while the ventricles relax • Atria push blood to the ventricles

Cardiac cycle • Right and left atria relax while ventricles contract • Atria fill with blood while ventricles push blood out of the heart

Why is coordinated contraction of the heart’s chambers important? ___ ensures that the heart’s chambers are filled and emptied at the right time ___ occurs when the atria beat irregularly and chaotically out of coordination with the ventricles ✓ Can lead to development of blood clots that may block upper chambers of the heart ✓ Can lead to heart failure, which is failure of the heart to push blood out to target organs)

Functions of ___ 1. Transports nutrients, gases, hormones and other solutes to all parts of the body, and removes metabolic wastes 2. Stabilizes pH, temperature, osmotic pressure 3. Regulates body temperature of endotherms 4. Functions for immune response 5. Functions for blood clotting

Components of Blood ___ (55%) - water, proteins, electrolytes, nutrients, respiratory gases, and metabolites ; yellow ___ (<1%) ; white ___ (45%) ; red

Components of blood • Mammalian ____ or red blood cells (RBC) appear (biconcave) in shape and without nucleus upon maturity • ¹ of birds and non-avian reptiles have nucleus • Appear red because of the presence of (hemoglobin), an iron-containing protein where oxygen temporarily binds while transported to distant organs • Lack mitochondria so the ¹ will not use bound oxygen for metabolism • Unique shape allows ¹ to squeeze through capillaries

Proteins that transport oxygen in animals • Protein that transports oxygen in most vertebrates • Has four protein subunits (two beta chains and two alpha chains) • Each subunit has heme porphyrin • Oxygen reversibly binds to iron (Fe2+) at the center of the porphyrin

Vertebrate without haemoglobin Blackfin icefish • Does not have erythrocytes and hemoglobin • Gills appear ___ Icefish Chaenocephalus acteratus • Blood appears opalescent or “___” compared to the blood of its close Antarctic relative

Proteins that transport oxygen in animals •Copper-containing protein that transports oxygen in molluscs and arthropods (some arachnids, many crustaceans and horse- shoe crabs) •Found in hemolymph

Proteins that transport oxygen in animals •Red iron-containing protein found in polychaete tube worms •Has no heme •With poor oxygen-carrying capacity compared to haemoglobin

Components of Blood: ____ • Play an important role in the body’s immune defenses against pathogens, damaged cells and cancerous cells • Some are capable of moving from blood to tissue spaces through (diapedesis)

Components of Blood: Leukocytes • Comprises 60% of leukocytes • With multi-lobed nucleus and numerous granules in its cytoplasm • Attacks bacteria

Components of Blood: Leukocytes • Comprises 2-4% of leukocytes • With bilobed nucleus and eosinophilic granules in its cytoplasm • Proliferates in association with allergens and parasites

Components of blood: Leukocytes • Comprises less than 1% of leukocytes • Nucleus may be band-shaped or segmented • Responds to allergic reactions

Components of Blood: Leukocytes • Largest and comprises 5% of leukocytes • With bean-shaped nucleus, no granules in cytoplasm • Transforms into macrophage in tissue spaces, which is capable of phagocytosis

Components of blood: Leukocytes • Comprises 30% of leukocytes • Without granules in cytoplasm • With round heterochromatic nucleus surrounded by thin rim of cytoplasm • Can be T ¹ or B ¹

Components of blood: Leukocytes Lymphocyte • Produced in the bone marrow and mature in the thymus

Components of Blood: Leukocytes T lymphocyte a) ___ T lymphocytes - release cytotoxic granules to kill cells infected with viruses and bacteria; even destroy cancer cells b) ____ T lymphocytes - activate both cellular and humoral arms of the immune system c) ____ T lymphocytes - can expand to a large number upon re-exposure to the same antigen

Components of blood: Leukocytes Lymphocyte • Differentiates into (plasma cells), which are capable of producing antibodies

Components of blood: Leukocytes B lymphocytes ___ are plasma proteins that mark pathogens or damaged/cancerous cells for destruction by other immune cells • Subpopulation become (memory B lymphocytes), which differentiates into plasma cells to produce antibodies upon re- exposure to the same pathogen

Components of Blood: ___ • Aka (platelets ) • Cytoplasmic fragments of (megakaryocytes ) • (Function for blood clotting ) • Attracted to site of bleeding where these attach and release their contents • Their contents activate other platelets and interact with other coagulation factors to eventually form a blood clot to stop the bleeding