Animal Transport Complete

Topics

Transport systems functionally connect the organs of

exchange with the body cells

Most invertebrates have a gastrovascular cavity or a circulatory system for internal support

Vertebrate phylogeny reflected in adaptations of the

cardiovascular system

Topics

Double circulation in mammals depends on the anatomy and pumping cycle of the heart

Structural differences of arteries, veins and capillaries correlate with their different functions

Physical laws governing the movement of fluids through pipes affect blood flow and pressure

Topics

Transfer of substances between the blood and the interstitial fluid across the thin walls of capillaries

Components of blood Cardiovascular diseases are the

leading cause of death in the United States and other developed nations

Invertebrates circulatory system Gastrovascular cavity

Presence of 2-cell thick body wall Serves for digestion and circulation Both layers are bathed by fluid Inner layer- only exposed to food

Invertebrates circulatory system Planarians and other flatworms

Also have gastrovascular system Body shape ensures the efficient

transfer of food

Open vs Closed Circulatory System Gastrovascular cavity

Not suitable for animals with many cell layers

Open vs closed Overcomes the limits of diffusion Three basic components

Circulatory fluid (blood) Tubes (blood vessels) Pumping organ (heart)

Blood pressure- motive force for fluid movement

Open circulatory system

No distinction between blood and interstitial fluid hemolymph

Sinuses- interconnected spaces that surround organs

Heart contraction Pumps hemolymph

Heart relaxation Draws hemolymph through ostia

Closed Circulatory System Blood

Confined to vessels Blood is distinct from interstitial fluid

Movement of materials Larger vessels to smaller vessels Exchange of materials is through

diffusion

Vertebrate Phylogeny is reflected in adaptations of the cardiovascular system

• Cardiovascular system- presence of heart and vessels

• Atrium- receives blood• Ventricle- pumps blood• Vessels

• Arteries• Veins• Capillaries

Vertebrate Phylogeny Is Reflected in Adaptations of the Cardiovascular System

Venules Arterioles Capillary beds High metabolic rate- complex

cardiovascular system Low metabolic rate- less complex

Fish heart

Two main chambers Gill circulation Systemic circulation

Frogs and Other Amphibians Three-chambered heart Presence of forked artery

Pulmocutaneous circulation Systemic circulation

Double circulation- restores blood pressure

Mixing of blood Reptiles

Presence of ridge in the ventricle

Mammals, birds and crocodilians Four-chambered heart Left side- oxygen-rich Right side- oxygen poor No mixing of blood

Double Circulation in Mammals Depends on the Anatomy and Pumping Cycle of the Heart

The Human Heart

Cardiac cycle- complete pumping and filling

Systole- contraction Diastole- relaxation Cardiac output- vol of pumped blood

into systemic circuit per min Heart rate- no of beats per min Stroke volume- amount of blood pumped

per contraction

The Valves

Atrioventricular (AV) valve Close due to ventricular pressure

Semilunar valves Aorta Pulmonary artery Open due to ventricular pressure

Heart murmur- hissing sound Pulse- rhythmic stretching of arteries

The Valves

Lub dup sound Lub- recoil of blood against closed AV

valves Dup- recoil of blood against semilunar

valves

Maintaining the Heart’s Rhythmic Beat Heartbeat- maintained by specialized

heart cell Sinoatrial (SA) node- sets rhythmic

beat Also called the pacemaker Found in the wall of right atrium, superior

vena cava Atrioventricular (AV) node- relay point

Found bet right atrium and right ventricle Impulses are delayed at 0.1 s

Heart rate

Electrocardiogram (EKG or ECG) Record of impulse produced in the heart

Heart beat

P wave Atrial contraction

QRS complex Ventricular contraction

T wave Ventricularrecovery phase

Structural Differences of Blood Vessels Correlate with Their Different Functions

Capillaries- lack two outer layers Arteries- thicker outer layers than

veins Veins- presence of valves

Movement of Fluid Through Pipes Law of Continuity

Blood Pressure

Blood Pressure- highest in arteries during ventricular systole

Hydrostatic Pressure Peripheral Resistance

Impedance caused by arterioles

Blood pressure is influenced by different factors Nerves- slows, speed up Hormones Body temperature Exercise Gravity- large animals

Transfer of Substances through Capillaries Two mechanisms that control blood

flow Contraction of smooth muscle

Constricts the arteriole that decrease blood flow

Dilation increases blood flow Precapillary sphincters

Control blood flow

Capillary exchange

Takes place in the endothelial wall Maybe carried though bulk transport

(endocytosis and exocytosis) Diffusion (O2 and CO2) Diffusion or bulk flow through

intercellular clefts

Blood

Plasma Cellular component

RBC hemoglobin

WBC Platelets