Blood Circulation & Transporation

Importance of Circulatory System

The transport of oxygen and nutrient

transport body heat and transmit force

transport waste to be excreted via lungs or kidneys

Gaseous exchange and nutrient-for-waste exchange take place in capillaries

Importance of circulation
Provide rapid mass transport water over distance where oxygen is insufficient or slow

Invertebrates

  • Do not have CS but gastrovascular cavity
  • Have open CS or,
  • have a closed CS

Vertebrates

  • All have CLOSE CS
  • Single loop or,
  • Double loop
    i. 2 atria & 1 ventricle
    ii. 2 atria & 2 ventricles

Open CS, arthropod, mollusc

  • Haemolymph
    i. mixture of blood & tissue fluid that flows into body cavity and is copper-based

Close CS, annelids

  • Blood
    i. contained within bloof vessel and iron-based haemoglobin

Invertebrates with Gastrovascular Cavity

Cnidarians

  • Cell exposed to water and can independently exchange gases, nutrient uptake and excrete waste

Flatworm

  • Has trilobed GC that branches throughout flattened body cell

Open CS in Invertebrates

  • Haemolymph pumped into tissue space via vessel and drains back to heart
  • Contraction of heart creates -ve pressure and draws blood from heamocoel into heart via ostia
  • Slow delivery of oxygen and nutrient but sufficient
  • Not suitable for large animals
  • Insects depend on tracheal respiratory system

Grasshopper

  • has colourless blood
  • Doesn't depend on Open CS
  • Trachea opento outside and take oxygen directly to muscles

Close CS in Invertebrates

  • Blood is pumped into capillaries for exchange of tissue fluid from small vein into dorsal vein that returns blood to heart
  • Has rhythmic pulsatile movement
  • Has fast circulation and blood retaining vessels to reach all area

Close CS in All Vertebrates


- Systemic circuit
heart pumps blood to body tissue


- Pulmonary circuit
Heart pumps blood to lungs

Birds, mammal and some reptiles

  • 2 atria 2 ventricles
  • PC and SC are separated
  • Right ventricle pumps into PC
  • Left ventricle pumps into SC

Fish

Amphibian and most Reptiles

  • 2 atria 1 ventricle
  • ventricle pumps blood to both circulatory circuits
  • Both oxygen rich and oxygen poor blood enter ventricle but is separated

Heart

Mammalians' heart - 4 chambers


Closed CS - cardiovascular system consist of heart and blood vessel


Septum - divides heart into left & right with 2 chambers each ( atrias & ventricles )

Heart valves


  1. Atrioventricular valves


    between atria & ventricles


  2. Semilunar valves


    between ventricles & attached vessels


  • Blood -> right atriov valves -> pulmonary semilunar valves -> pulmonary trunk -> pulmonary arteries take it up to the lungs

- Pulmonary vein brings O2- rich blood back to left atrium



  • Blood -> left atriov valve -> left ventricle pumps -> aortic semilunar valve -> aorta -> tissue


  • Heart murmur


    Due to leakage of atrioventricular valve allowing blood flow back into atria after its closed

Rhythmic Heartbeat

  • each heartbeat - cardiac cycle consist of :

i. atria contracts
ii. ventricle contracts
iii. all chambers rest


systole - contraction
diastole - relaxation


Pulse - wave effect passed down arterial vessel following systole


Rhythmic contraction due to cardiac conduction system


Sinoatrial ( SA ) - node initiate heartbeat & called cardiac pacem


Electrocardiogram ( ECG ) - record electrical changes in cardiac cycle

Blood vessel

Arteries
carry blood away from heart to capillaries


  • have thick walls & elastic tissue
  • can accomodate sudden increase in blood volume
  • branches into smaller arterioles

Capillaries
allows the exchange of materials with tissues


  • very narrow with thin walls made of single layer of epithelium with basement membrane
  • Thin walls to facilitate capillary exchange

Vein
return blood from capillaries to heart

  • Venules drains blood from capillaries
  • Often have valves to prevent backflow of blood

Circulatory Circuit

Pulmonary Circuit

  • O2- poor blood is collected in right atrium and passed into right ventricle to be pump into pulmonary trunk then lung
  • Blood passes through pulmonary capillaries and gaseous exchange occur
  • O2- rich blook returns to left atrium via pulmonary veins

Systemic Circuit

  • Major vessel : Vena cava & aorta
  • Blood pumped into left ventricle -> aorta -> organ -> vein -> vena cava -> right atrium

Portal system
begin & ends at capillaries

  • Hepatic portal syst takes blood from intestines to liver

Blood Pressure


Systolic pressure
Blood being forced into arteries during ventricular systole


Diastolic pressure
Pressure in arteries during ventricular diastole


  • As blood flows from aorta into various arteries, pressure falls
  • Blood pressure is low in vein and depending on
    i. Skeletal muscle contraction
    ii. Valves of vein
    iii. Respiratory movement

Cardiovascular Disease


Hypertension
Occurs due to plaque protrudes into lumen of vessel and interferes blood flow


Stroke
Occurs due to small cranial arteriole bursting or embolus blockage


Heart attack
Conorary artery completely blocked causing heart muscle to die due to lack of oxygen

Blood

Function

  • transport nutrient from digestive tract to tissue, to & from storage organ
  • transport of metabolites for metabolic specialisation
  • transport excretory products from tissue to excretory organ, from organ of synthesis
  • transport gases between respiratory organ & tissue
  • transport of hormone
  • transport of cells of non-respiratory functions
  • transfer of heat
  • transmission of force

Blood stem cell


Stem cell capable of specializing into many type of cells however adult stem cells have limited capability.


Adult stem cell richest in red bone marrow and used to treat white blood cell disorder

Type of blood cell

White blood cell
fight infection

Red blood cell
transport oxygen using haemoglobin

Lymphocytes fight infections

B cells produce antibodies

Neutrophils

T cells attack cells infected with virus

Monocytes act as phagocytes

Eosinophils combats multicellular parasites and mediates allergy response

Basophils prevent blood from clotting too quickly with heparin, parasitic & allergy responses

Blood disorder
eg: Hemophilia - clotting disorder, recessive sex-linked , X chromosome disorder

ABO System
A , B, AB, O

RH System & Erythroblastosis Fetalis
RH factor - antigen matching in blood type


Erythroblastosis Fetalis

  • Mother with Rh -ve & father with Rh +ve and fetus possibly with Rh +ve
  • Opposite Rh of child may leak out of placenta causing mother to produce Rh-ve antibodies that may destroy fetus with opposite Rh in the next pregnancy

Lymphatic System

  • vessel found in all tissues except central neural system, bone marrow and tissues without blood vessels

Function

Lympoid Organs

Immunological Defense

Fluid balance

Fat absorption & transportation

Primary
- production and selection of lymphocyte

Secondary

  • Site of lymphocyte activation by antigen

Bone Marrow

Thymus

Lymphoid follicles in tonsils

Peyer's patches

Lymph node

Spleen

Skin

Disorder

  • Lymphedema
  • Elephantiasis