<

Cytology biology Course LowerSixth Science

CHAPTER VIII: VASCULAR TISSUE (BLOOD)

Introduction

           This is a highly specialized reddish tissue consisting of red blood cells, white blood cells and platelets suspended in a liquid inter cellular matrix called plasma. The main function of blood is to transport materials and gases, fight against diseases and the formation of dats. The many functions of blood are possible because of the various cells and fragments its contents.

 

  1. Red blood cells or erythrocyte

 

  • It transports respiratory gases to and forms the tissues. Their structure is greatly modified for these purpose
  • The cytoplasm of a mature red blood has no nucleus and is depressed on each side giving it a biconcave shape
  • The interior of the cell is filled with the red pigment hemoglobin which have a high affinity or oxygen
  • The lack of nucleus and his biconcave shape enable more hemoglobin to be packed inside the cytoplasm
  • Its thin elastic membrane makes it possible for oxygen to easily diffuse across and combine with hemoglobin for it to be transported.

 

 

  1. White blood cells or leucocytes

 

  • It defend the body against disease causing micro organisms the body actives defend mechanisms are carried out by two types of white blood cells
  • Granulocytes have a granular cytoplasm and lobe-shape nucleus e.g. neutrophils which undergoes phagocytosis destroying bacterias
  • A granulocyte have a non granular cytoplasm and a spherical nucleus e.g. lymphocytes which produce anti-bodies that neutralize the toxin produce by microbes.

 

 

 

  1. Platelets (thrombocytes)

 

These are minutes cell fragments. They function in the mechanisms when a blood vessel is damage thus preventing excess lost of blood and also preventing the entering of pathogens into blood.

 

Structure

Voluntary muscle

Involuntary muscle

Cardiac muscle

 

Fibres are elongated,

Fibres are spindle shape

Are branched

Are multi nucleated

Are uninucleated

Are uninucleated

Cross strations present

No cross stration

Paint cross stration and presence of intercalated disc

Nucleus is located at the periphery of fibres

Centrally located

Centrally located

Sarcolemma is present and encloses fibres

Sarcolemma present

No sarcolemma

Location

Constitute most of the meat or flesh of an animal and often found attach to bones

Found in the walls of hallow structure like the gut, bladder, blood vessels

Found only in the walls of hearts

Functioning

Contract fast but subject to fatigue rapidly

Contract slowly and never fatigue

Contract fast and never fatigue

Under the control of the will

Not under the control of the will

Contraction is myogenix, initiated by the muscle itself and not by the nervous system

Others names

Striated or striped or skeletal muscle

Unstriated, unstriped, plain, smooth, or visceral muscle

Heart muscle

 

 

 

 

 

par Claude Foumtum


Cytology biology Course LowerSixth Science





CHAPTER IV: COMPOUND PLANT TISSUES

CHAPTER V: ANIMALS TISSUES

CHAPTER VI: CONNECTIVE TISSUES

CHAPTER VII: MUSCLE TISSUES

CHAPTER VIII: VASCULAR TISSUE (BLOOD)