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Case 3: Obj 5,6,7

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Case 3: Obj 1,2,3,4

L3-The cell membrane

INTRODUCTION

•The cell is the living unit of the body.

•Group of cells →Tissues→Organ→Systems→Living Organism.

BODY FLUID

Intracellular Fluid

•Fluid inside the cells of the body.

•High Na & less K

The extra cellular fluid

•Interstial fluid circulate in the spaces between the cells.

•Plasma of the blood

•High K Less Na

CELL MEMBRANE

•All animal cells are enveloped by a cell membrane

•It is composed of lipid and protein

•It is semi permeable membrane

Picture1

Function of cell Membrane

1.Separates between cytoplasm & ECF

2.Maintain cell internal environment.

3.Transport of molecules in & out the cell

4.Controls ions distribution between cytoplasm and ECF

5.It contains protein receptors for hormones &chemical transmitter.

6.Generates membrane potentials

Components of the cell membrane

•It consists of two layers of phospholipids molecules. It resemble the pin shaped.

•The head composed of protein and lipid .

•The heads are soluble in water (hydrophilic)

•The tails are insoluble in water (hydrophobic)

•They meet in the interior of the membrane

Picture2Picture3

Cell membrane protein

There are two types of proteins

(1) Integral or intrinsic protein

1.Channels through which small water soluble substance can diffuse.

2.Carrier which actively transport material across the membrane.

3.Receptors which when activated initiate intracellular reaction.

4.Enzymes.

(2) Peripheral or extrinsic protiens:

•Composed of glycolipid and glycoprotein.

•Binds to extracellular calcium to stabilize memberane.

•Acts as attachment matrix for other cells

Picture4

Transportation through cell membrane

1.Diffusion.

2.Active transport.

3.Vesicular transport.

Picture5

1.Diffusion:

•either simple diffusion or facilitated diffusion.

Simple diffusion: the substance cross the cell membrane by simple movement without binding with carrier protein.

Facilitated diffusion: carrier mediated diffusion.

Picture6

2.Active transport:

Movement of substance against concentration gradient.

•Needs energy from hydrolysis of ATP

•Either:

1-primary active transport.

2-secondery active transport

Picture7Primary Active transport:

1-Na-K pump

•Present in the cell membrane

•Transport Na (out)  from ICF to ECF

and K (in) from ECF to ICF

2- K-H ATpase (proton pump)

•Present in stomach. Transport H ions into the lumen against concentration gradient.

Secondary  Active transport:

1.Na- glucose co-transport: needs carrier which contain two binding sites for Na and glucose.

2.Na- Ca exchange: present in ventericular muscles.

3.Vesicular transport mechanism:

1.Endocytosis: (phagocytosis & pinocytosis)

2.Exocytosis: (cell vomiting)

L2 – Physiology of Blood

BloodDrip

Introduction

  • Blood is a reddish fluid that circulates continuously inside the CVS. by the pumping action of the heart
  • It has many important functions which are essential for life.
  • Sudden loss of more than 30% of the total volume leads to death.

Functions of the blood

1-Transport function:

  • O2 & CO2
  • Nutrients from digestive system to cells.
  • Removal of waste products.
  • Hormones from endocrine glands to cells.
  • Enzymes and vitamins.

Picture4

2-Regulatory functions:

  • PH of the blood: it contains buffer system.
  • Body temperature: through heat loss from skin.
  • Regulation of ABP: due to its viscosity

3-Protective function:

  • Gamma globulin which form antibodies for immunity.
  • White blood cell (WBC) phagocytosed microorganism.
  • Clotting factors prevent blood loss.

Composition of blood

Picture5

1.Cellular elements: represents about 45% of the total blood volume.

2.Plasma 55%.

Picture4

1) PLASMA

  • —Water 90% —
  • Organic substance 9%

-Plasma proteins 7% (albumin, globulin, firinogen)

-Other organic substance 2%

(metabolic products urea creatinine, nutritive substance like Glucose & Amino Acids, Enzymes, hormones,vitamines)    —

  • Inorganic substance 1%

– Na, K, Ca, Cl

-Respiratory gases O2, CO2

Picture6

Plasma Protein Functions

  1. Blood coagulation:  fibrinogen & prothrombin.
  2. Blood viscosity: 2 times more than water & maintain diastolic bl. Pressure.
  3. Production of an effective osmotic pressure maintaining body fluid.
  4. Buffering action.
  5. Defense action. Antibodies are gamma globulins
  6. Carrier functions: vitamins, Iron, copper, cholesterol, phospholipids, hormones e.g. Thyroxin, cortisol.
  7. Carriage of CO2.
  8. Regulation of capillary permeability.
  9. Protein metabolism.

2)Cellular Elements

1)RBCs:

  • 5 million/mm3.
  • decrease in No. causes anemia
  • increase causes polythycemia.

2)WBCs:

  • 4000-11000/mm3
  • decrease No. = leukopenia
  • increase No. = leukocytosis.

3)Platelets: (Thrombocytes):

  • 150-400 thousands/mm3 ↓
  • decrease no = Thrombocytopenia
  • increase no = Thrombvocytosis.

Picture3

Picture2Blood Cell Development

Red Blood Corpuscle (R.B.C)

-Shape: small circular biconcave disc.

-Diameter: 7.5 micron

-Number:

  • male 5- 5.5 million/mm3
  • female 4.5- 5 million/mm3

-Hb content:

  • male 14-18 gm%
  • female 12-16 gm%
  • newborn 18 gm%
  • children 12 gm%

Picture7Function of RBCs

A-Functions of the membrane:

1-Has large surface area in relation to quantity inside it.

  • Facilitates gas exchange
  • Allow passage through narrow capillaries.
  • In case of hydration the red cell can swell and become more spherical but don’t rupture.

2- Contains different channels for passage of ions to maintain normal ionic composition.

3- Contains protein antigen which are responsible for the specific blood group of the person.

4- Keep the Hb and carbonic anhydrase inside the red cell. If these substances are set free in plasma it will be:

-lost in urine

-ppt in kidney as acid haematin leading to renal failure.

B-Functions of the content

-Hemoglobin (Hb):

  • Carrier of O2 & CO2.
  • Blood viscosity.
  • Acid base balance

White Blood Cells ( W.B.C)

-Number : 4000-11000/mm3.

-Types:

1-Granular:

  • Neutrophils 60%
  • Eosinophil 1-5%
  • Basophil 0.5-1%

2-Non granular:

  • Monocyte 3-8%
  • lymphocyte 20%

Picture8

Functions of W.B.C  (Defense mechanism):

  • Neutrophil: phagocytosis.
  • Eosinophil:
  1. defense against parasite.
  2. modulate allergic reaction.
  • Basophil: synthesize and liberates heparin into blood.
  • Lymphocytes: T and B (immunity)

PLATELETS

-Has a role in haemostasis:

  • Release of serotonin which produce vasoconstriction.
  • Formation of platelet plug.

-Plug formation

  1. Platelet adhesion: to the injured area, enhanced by collagen & VonWillebrand factor
  2. Platelet activation: swelling- pseudopodia- stickiness
  3. Platelet disintegration: release of ADP & ThromboxanA2 whish attract more platelets
  4. Platelet aggregation: the process is repeated until a plug is formed.

Picture9Picture10

S1/Case 3 – Active & Passive Movement

Objective

1)Be able to define the physical characteristics of the blood and its functions in the body

2)List the features and types of cells in the blood

3)Be able to describe the plasma and its functions

4)Understand and describe the structure and molecular organization of the plasma membrane

5)Be able to define Diffusion , Facilitated Diffusion , Osmosis , Active Transport , Endocytosis , Exocytosis , Phagocytosis , and Pinocytosis & give examples of each

6)Understand the functions of the different components of the membrane and their organization

7)Understand the structure and function of the microfilaments and microtubules

8)Understand the principles of osmosis and semi-permeable membranes

9)Understand what is meant by heat ang temperature

10)Understand the optics of light microscope

L1 – Histology of Blood Cells

THE BLOOD

•Definition:-

It is the viscid fluid,  present in the closed circulatory system

Contents:

1-blood cells:

•They  form about 45% of the blood volume.

•The Blood cells are:-

a- Red cells (erythrocytes).

b- White cells (leukocytes).

c- Blood platelets (thrombocytes).

2-Plasma:

•it forms 55% of the blood volume

Picture1

BLOOD CELLS

(1) RED BLOOD CORPUSCLES (RBCS) / Erythrocytes

A- Shape of RBCs:-

•They are biconcave disc shape.

•In slow blood stream and in blood film they adhere together forming “Rouleaux” due to high surface tension.

B- Size:-

•Normal diameter: 6-9 um (average 7.5 um).

Picture2

C- Colour:-

Fresh, single RBC is greenish yellow due to minimal HB.

•A drop of blood  appears red as it contains large number of RBCs.

•In stained sections, RBCs with normal HB appear acidophilic with pale centre (normochromic).

D- Number:-

•In males:    5 – 5.5 million /mm3.

•In females: 4.5 – 5 million /mm3.(due to loss of blood during menstruation and depression of bone marrow by female sex hormones).

E- Structure of RBCs:-

They are non nucleated cells (now called corpuscles).

•They have no organoids but filled with HB.

•They are surrounded by cell membrane, which is plastic and has selective permeability.

•They contain important enzymes e.g. carbonic anhydrase enzyme.

F- Adaptation of RBCs to its function:-

•Its biconcave shape increases surface area for more gas exchange. •Absence of nuclei and cell organoids allows more space to HB for gas exchange.

•Carbonic anhydrase enzyme plays an important role in transportation of CO2 from tissues to the lung.

•Selective permeability of the cell membrane allows easy exchange of oxygen and CO2 but not HB.

•Plastic cell membrane allows RBCs to be squeezed in narrow vessels, then regain its normal shape in wide vessels thus prevent their rupture.

(2) LEUCOCYTES (WBCS)

A- Definition:-

They are true nucleated cells having cell organoids, cell inclusions, but no hemoglobin.

B- Colour:

•Single WBC is colourless (leucocyte) but when aggregated, they appear white (WBCs).

C- Number:

4000-11000/mm3

D- Classification of leucocytes:

1-Granular leucocytes:-

a- Neutrophils.

b- Eosinophils.

c- Basophils.

2- Non-granular leucocytes :-

a- Lymphocytes.

b- Monocytes.

Neutrophils (polymorphonuclear leucocytes)

A- Percentage:60-75% of total leucocytes.

B- Shape:spherical

C- Size: 10-12 um.

D- Nucleus:-

•Single, dark stained and segmented (2-5 segments connected by fine chromatin threads.

•About 60% of female nuetrophils have Barr bodies attached to their nuclei.

E- Cytoplasm:-

•contains fine neutrophilic granules.

F- E/M:

•Few mitochondria

• endoplasmic reticulum.

•Two  types of granules are present:-

  • Specific granules:
  1. •Numerous & small in size.
  2. •Contain  bacteriostatic and bactericidal substances.
  • Azurophilic granules:
  1. •Few in number  & large in size.
  2. •Contain  hydrolytic enzymes (lysosomes).

G- Life span: 1- 4 days.

H- Functions:-

Defense against microorganisms.

•When microorganism invades the surrounding tissue, the neutrophils migrate from the  capillaries and  phagocytose it (so called microphages).

•They also secrete proteolytic enzymes.

•During infections, they stimulate the bone marrow to produce more leucocytes (neutrophilia).

•They attract monocytes to the infected area.

•Precipitate in pus formation.

•They secrete trephone substances, that help in healing of wounds.

Picture5

Eosinophils

A- Percentage2- 5% of total leucocytes.

B- Shape: spherical

C- Size: 12-15 um.

D- Nucleus: Bilobed “horse shoe-shaped”.

E-Cytoplasm: contains acidophilic refractile granules.

F-E/M :-

•Few mitochondria, rER, and Golgi.

•Coarse  ellipsoid granules, with electron dense crystalloid core in the centre.

•These granules contain histaminase and sulphatase enzyme.

G- Life Span: 8-12 days.

H-Functions:-

1-In allergic conditions, the mast cells attract eosinophils to the site of allergy to perform anti-allergic action

2-They can phagocytose the antigen-antibody complex.

3-They secrete histaminase and sulphatase enzymes which destroy histamine and sulphate substances of allergy.

Picture6

Basophils

A- Percentage½  –  1 %  of  total leucocytes.

B- Shape: spherical

C- Size: 10 – 12  um.

D- Nucleus: Large and irregular.

E- Cytopasm:-

•Filled with large basophilic granules.

•These granules can be stained metachromatic .

•They also stained with Giemsa stain.

F- E/M :-

•They contain coarse electron dense granules.

•These granules contain histamine and heparin.

G- Life Span: 10-15  days.

H- Functions:-

•They produce heparin and histamine during allergy.

•They have minimal phagocytic activity.

•They release eosinophil chemotactic factor.

Picture7

Lymphocytes

•Non granular leucocytes

Percentage: 25-30%.

Classification :

1-Small sized lymphocytes:     4-7 um.

2-Medium sized lymphocytes: 7-10 um.

3-Large sized lymphocytes:     10-15 um.

•Lymphocytes found in the blood are mainly small and medium sized, while the lymphoid organs contain the three types.

Large or medium-sized lymphocytes

A- Percentage5-10%.

B- Size: 10 –   12  um

C- Nucleus: Large, pale and indented.

D- Cytoplasm: abundant, more basophilic and non granular.

E- E/M :-

•The cytoplasm contains polyribosomes, numerous mitochondria, large Golgi and lysosomes.

Picture8Small Lymphocytes

A- Percentage15-20%.

B- Shape: spherical.

C- Size:6-8 um.

D- Nucleus:-

•Central, round and dark stained.

•Surrounded by a thin rim of cytoplasm.

E- Cytoplasmfew in amount & pale basophilic.

F- E/M:-

•They have few ribosomes, few mitochondria, a very small Golgi and few azurophilic granules.

G- Classification:-

  1. B. lymphocytes.
  2. T. lymphocytes .

Picture9B- lymphocytes

Development:

-U.M.C in the bone marrow  colony forming cells … B. lymphoblast…  B. lymphocyte.

Percentage : 30%   lymphcytes.

Types :

  1. B.lymphocytes of humoral immunity.
  2. B.memory cells.

Life span:3months

Function :-

1Humoral immunity:

•When exposed to antigen, they are activated into medium sized lymphocytes.

•Some of the active cells are differentiated into plasma cells which produce antibodies.

•This is called primary immune response.

2- Secondary  response (B memory cells):

•Some of the active cells are not changed into plasma cells but remain as memory cells.

•When exposed to the same antigen again, they produce more rapid and more extensive humoral immune response.

T. Lymphocytes

Development:

-UMC in the bone marrow colony forming cells which migrate to the thymus gland where they develop into T.lymphocytes (thymus dependent).

Percentage: 70 %  of  small  lymphocytes

Life span: years.

Types:

  1. T. killer cells: produce cytotoxic substances.
  2. T. memory cells
  3. T. helper cells.
  4. T. suppressor cells.
  5. Lymphokines secreting cells.

Function:-

  • 1•Cell mediated immunity:-

•When exposed to cellular antigen, the T-lymphocytes are activated and come in contact with the antigen.

•They secrete cytotoxic substance to destroy it.

  • 2•Graft rejection cells in organ transplantation:

(by cell mediated immunity).

  • 3•T-memory cells:

•Some of the activated T-cells remain in the body as memory cells, that can attack the same antigen after a long period of time.

  • 4•T-helper cells:-

•T-lymphocytes, can help the B-lymphocytes to be activated by the antigen.

  • 5•Secretion of lymphokines:

•Interferon: antiviral.

•Colony stimulating factor: stimulate bone marrow cells.

•Macrophage factor: antibacterial.

  • 6•They act as macrophage attracting cells .

Picture10

Monocytes

A- Percentage: 3-8%.

B- Size: 15  um .

C- Nucleus: large, pale and kidney shaped.

D- Cytoplasm: abundant and appears pale blue.

E- E/M :-

•Many microvilli and pinocytotic vesicles near the cell surface.

•Few cell organelles, small Golgi and azurophilic granules (lysosomes).

F- Life Span: 3 Days

G- Function:-

•Monocytes can penetrate through capillaries and venules to reach the C.T. where they can be transformed into macrophages.

(3) PLATELETS (THROMBOCYTES)

Picture11

A- Definition :

•They are fragments of cytoplasm  covered  with membrane but have no nucleus (not true cells).

B- Origin :

•Megakaryocytes in the red bone marrow.

C- Size:

•2 – 4 mm.

D- Shape :Picture12

•oval or rounded discs.

E- Number:

•150.000 – 400.000  /  mm3.

F- L / M :

•Appear as oval or rounded non nucleated discs.

•Their outer part appears transparent and pale blue (called  hyalomere).

•Their central part contains dark stained granules (called granulomere).

G- E/M:-

1-Cell membrane:-

Irregular and covered with a thick cell coat.

2- Hyalomere:-contains

  1. Tubules & vesicles invaginated from the cell membrane.
  2. Actin-like mirofilaments and microtubules to maintain the ovoid shape of the platelet.

3- Granulomere: (chromomere):-contains

  1. Alpha granules: contain fibrinogen.
  2. Beta granules: mitochondria .
  3. Delta granules: contains serotonin, ATP, ADP and calcium.
  4. Lambda granules: lysosomes.
  5. Glycogen granules.

Picture13H- Life span:

•5-10  days

I- Function :-

•Stop  bleeding (haemostasis) through :

1-Secretion of serotonin → vasconstriction → decrease blood loss.

2-The platelets adhere to the inner wall of the injured blood vessels  forming platelet aggregation or white thrombus.

3-Then, they secrete thromboblastin →  change prothrombin into thrombin →  change fibrinogen into fibrin network → attract RBCs to form red thrombus (coagulation) which close blood vessels and stop bleeding.

Picture14RBC

Picture15NEUTROPHILS

Picture16Picture17Picture18Picture19Picture20

Anomalies in Blood Cells Values

Picture21
RBC

1- Anaemia or oligocythemia

• Decease in number is caused by:-

  1. Deficiency of iron, vit.B12, proteins, copper.
  2. Defect in bone marrow → aplastic  anaemia.
  3. Haemorrhage → haemorrhagic   anaemia .
  4. Haemolysis → haemolytic anaemia.

Causes of haemolysis are :-

  1. Incompatible blood transfusion.
  2. Acids and alkalies.
  3. Bacterial toxins and viruses.
  4. Snake venom.
  5. Hypotonic solutions and fat solvents.

2- Polycythaemia

a- Haemoconcentration:

•The actual number of RBCs does not increase but the volume of plasma is reduced.

•Occurs in cases of dehydration due to vomiting, diarrhea or polyuria. 

b- Compensatory polycythaemia :

•There is actual increase in production of RBCs from bone marrow.

•Occurs as compensatory to hypoxia as in:-

  1. The foetus due to intrauterine anoxia.
  2. High attitude in low O2.
  3. Severe muscular exercise →need for O2.
  4. Congenital heart diseases→ mixed blood.
  5. Chronic lung conditions → impaired oxygenation of blood

Neutrophils

1- Neutropenia:

•It is a decrease of neutrophils below 60%.

•It occurs in:

  1. Influenza
  2. measles
  3. starvation
  4. severe poisoning
  5. chronic infections eg. Typhoid & TB.

2- Neutrophilia:

•It is an increase of neutrophils above 75%.

•It occurs in:

  1. Pyogenic infections: e.g. tonsilitis, appendicitis
  2. Myocardial infarction.

Eosinophils

1- Eosinophilia:

-Allergic diseases.

-Parasitic infections e.g. bilharziasis.

2- Eosinopenia :

-It occurs after:-

  1. Prolonged steroid therapy.

Basophils

1- Basophilia

-Allergic diseases.

-Parasitic diseases.

-Liver cirrhosis.

Lymphocytes

1- Lymphocytosis:

•Whooping cough.

•TB.

•Syphilis.

•Glandular fever

Monocytes

1- Monocytosis:

•Malaria.

•Typhus.

•TB.

•Syphilis.

•Glandular fever.