Functions of skin

Functions of skin

Introduction : skin is the largest organ of the body. It's thickness about 1-5mm according to location.

Skin is made up following two layers...

1. Outer epidermis:  formed by the stratified epithelium.

2. Inner dermis: formed by the fibroblast, collagen fibers and histiocyte.

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Functions :

1. Protective function: skin forms covering of all organs of the body and protects from Bacteria, Toxic substances, Mechanical blow and Ultraviolet rays.
2. Sensory function: skin is considered as the largest sense organ of the body. It has many nerve endings which form specialized receptors. These receptors are stimulated by sensation of touch, pain, pressure and temperature convey these sensation to brain.
3. Storage function: skin stores fat, water, chloride and sugar.
4. Vitamin D3 : vitamin D3 is synthesized in skin by the action of ultraviolet rays on cholesterol.
5. Regulation of body temperature:  Excess amount of heat is loss from body through skin by radiation, conduction, convection, evaporation. Sweat also done loss of heat by sweat glands. The lipid content of serum prevent loss of heat from the body in cold environment.
6. Regulation of water and electrolyte balance: Skin secrets sweat which contain water and salt.
7. Excretion: Skin excretes small amount of waste material like urea, salt and fatty substances.
8. Absorption: Skin can absorb the fat soluble substances and some ointment.
9. Secretions : Skin secretes sweat through sweat glands and sebum through sebaceous glands.

Functions of skin

Asphyxia

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Asphyxia

Definition : improper aeration of blood if continued for some time , then it produce a series of pathological changes and finally cause death which is known as Asphyxia.

                                       OR

Asphyxia is the condition characterized by combination of hypoxia and hypercapnea, due to obstruction of air passage.

Codition when asphyxia occurs: acute obstruction of air passage due to...

   i. Strangulation .

  ii. Hanging.

 iii. Drowning.

Stages of asphyxia:

1. Stage of  Hyperpnoea:  in this stage breathing becomes deep and rapid because of the powerful stimulation of respiratory centre by the excess carbon dioxide. Hyperpnoea is followed by dyspnea and cyanosis and eyes become more prominent. Duration of this stage extends only 1min.

2. Stage of convulsion or central excitation:  in this stage hypercapnea acts on brain and produce following effects...

          i. Violent expiratory efforts.

         ii. Generalized convulsion.

        iii. Increase heart rate.

        iv. Increase arterial blood pressure.

         v. Loss of consciousness.

Duration of this stage less then 1 min.

3. Stage of collapse / central depression / slow deep inspiration: in this stage severe hypoxia produce following effects...

          i. Depression of centers in brain and disappearance of convulsion.

         ii. Development of respiratory gasping with open mouth.

        iii. Dilation  of pupils.

        iv. Decrease heart rate.

         v. Loss of all reflexes.

Duration of this stage about 3 min.

All together asphyxia extends only for 5 min.


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Hypoxia / Anoxia

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Hypoxia / Anoxia

Definition : Decrease oxygen level in blood or inadequate supply of oxygen to the tissues by the blood are known as Hypoxia.

Causes : 

1. Oxygen tension in arterial blood.
2. Oxygen carrying capacity of blood.
3. Velocity of blood.
4. Utilization of oxygen by the cell.

Classification :

1. Hypoxic hypoxia / Arterial hypoxia:  low oxygen tension in arterial blood.

2. Anemic hypoxia : low oxygen content of blood due to...

               I. Lack of Hb.

              II. CO poisoning. 

3. Stagnant hypoxia / Hypokinetic hypoxia:  decrease rate of blood flow due to its velocity.

4. Histotoxic hypoxia : tissue are unable to use oxygen.

Effects of hypoxia:

1. On nervous system - 

     i. Dullness.

     ii. Dizziness.

    iii. Confusion.

    iv. Convulsion.

2. On digestive system:

    i. Nausea.

   ii. Vomitting.

  iii. Vertigo.

   iv. Loss of appitite.

3. On circulatory system:

    i. Increase heart rate.

   ii. Increase cardiac output.

  iii. Increase blood pressure.

   iv. Cyanosis.

4. On respiratory  system: 

    i. Hyperpnoea.


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Dyspnoea

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Dyspnoea

The term ''Dyspnoea" mean's difficulty in breathing. It is also known as Air hunger. 

           In normal condition breathing remains unnoticed, when this breathing is notice or comes in consciousness known as Dyspnoea.

Definition : Difficulty in breathing called Dyspnoea.

Causes:  

1. Hypoxia
2. Hypercapnia / Hypercarbia.
3. Increase H+ ion concentration.
4. Abnormality of diaphragm.
5. Abnormality of chest wall.
6. Failure of ventricles of the heart.
7. Severe anaemia.
8. Tissue lungs expiration.
9. Pneumonia.
10. Pulmonary edema.
11. Poliomyelitis .
12. Pneumothorax .
13. Severe asthma.

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Respiratory system (volumes & capacities)

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Respiratory system 

Volumes : 

1. Tidal volume (TV) : TV is the volume of air breathed in and out of lungs in a single normal quiet respiration. 

Normal value - 500ml.

2. Inspiratory reserve volume (IRV) : IRV is an additional volume of air that can be inspired forcefully after the end of normal inspiration .

Normal value - 3300ml.

3. Expiratory reserve volume (ERV) : ERV is an additional volume of that can be expel out forcefully after normal expiration.

Narmal value - 1000ml.

4. Residual volume (RV) : RV is a amount of air remain in the lungs after forceful expiration.

Normal value - 1200ml.

Capacities: 

1. Inspiratory capacity (IC) : IC is the maximum volume of air that is inspired after normal expiration . It includes...

IC (3800)= TV (500) + IRV (3300).

Normal value - 3800ml.

2. Vital capacity (VC) : VC is the maximum volume of air that can be expel out forcefully after a deep inspiration . It includes...

VC (4800) = IRV (3300) + ERV (1000) + TV (500).

Normal value - 4800ml.

3. Functional residual capacity (FRC) : FRC is the volume of air remaining in the lungs after normal expiration. It includes...

FRC (2200) = RV (1200) + ERV (1000).

Normal value - 2200ml.

4. Total lungs capacity (TLC) : TLC is the volume of air present in lungs after a deep inspiration . It includes all the volumes like...

TLC (6000) = IRV (3300) + ERV (1000) + TV (500) + RV (1200).

Normal value - 6000ml.


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Cell membrane

Cell membrane

Definition : it is a protective sheath, and it is also known as plasma membrane, plasmalemma. This membrane separate ICF from ECF. it is a semipermeable membrane. Thickness of the cell membrane 75-111°A.

Composition of cell membrane :

1. Protein - 55%
2. Lipid - 40%
3. Carbohydrate - 5%

Lipid layer of cell membrane : 

1. Phospholipid.
2. Cholesterol .

Protein layer of cell membrane :

1. Integral protein - that pass through entire thickness of cell membrane from one side to other side.

Example of integral protein:  

1. Cell adhesion proteins.
2. Cell junction protein.
3. Some carrier or transport protein.
4. Channel protein.
5. Some hormones receptor.
6. Antigens.
7. Some enzymes.

2. Peripheral protein - are the partially embedded in the outer or inner surface of the cell membrane .

Example of peripheral protein :

1. Proteins of cytoskeleton.
2. Some carrier or transport protein.
3. Some enzymes.

Functions of cell membrane :

1. Protective function .
2. Selective permeability .
3. Absorptive function.
4. Excretory function .
5. Exchange of gases.
6. Maintenance of shape and size of the cell.
7. Transportation.

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Cytoskeleton

Name :- Cytoskeleton

Properties :

• It is an cellular organelle present throughout the cytoplasm.
• It is a complex network of structures with varying sizes.
• Cytoskeleton is consists of three major protein components i.e. microtubule, intermediate filaments and microfilaments.

Microtubules :

• These are the straight, hollow and tubular structures. 
• These organelles are arranged in different bundles without the limiting any membrane. 
• Each tubules has 20-30 nano-meter diameter and length varies, it may be 1000 times more than the thickness. 
• Microtubules are formed by bundles of globular protein called tubulin. Tubulin has two subunits i.e. alpha and beta.

Intermediate Filaments (IF) :

• IF form a network around the nucleus and extend to the periphery of the cell.
• Diameter of each filament is about 10 nano-meter.
• IF are formed by rope-like protein polymers (fibrous proteins)
• IF are divided into five subclasses :-
• Keratins (in epithelial cells)
• Glial flaments (in astrocytes)
• Neurofilaments (in nerve cells)
• Vimentin (in many types of cells)
• Desmin (in muscle fibers)

Microfilaments :

• These are long and fine thread-like structures.
• It's diameter is about 3-6 nano-meter.
• These are present throughout the cytoplasm.
• These are formed by non-tubular contractile proteins (actin and myosin).
• Microfilaments contain only actin molecules when these are present in ectoplasm.
• Microfilaments contain actin and mysosin molecules when these are present in endoplasm.

Functions of ... 

Cytoskeleton :

1. It determines the shape of the cell and gives support to the cell.
2. It is essential for cellular movements.
3. It is responsible for response of the cell to external stimuli.
4. It helps in cell division.

Microtubules : It may function alone or join with other proteins to form complex structures like cilia, flagella or centrioles and perform various functions.

1. Determine the shape of the cell.
2. Give structural strength to the cell.
3. Act like conveyer belt which allow the movement of granules, vesicles, protein molecules and some organelles like mitochondria to different part of the cell.
4. Form the spindle fibers which separates the chromosomes during mitosis.

Intermediate filaments :

1. Helps to maintain the shape of the cell.
2. It connect the adjacent cells through desmosomes.

Microfilaments : 

1. Give structural strength to the cell.
2. Provide resistance to the cell against the pulling forces.
3. Responsible for cellular movements like contraction, gliding and cytokinesis (partition of cytoplasm during cell division).

Similar Posts ....

• Golgi apparatus
• Ribosomes
• Rough Endoplasmic Reticulum
• Lysosomes
• Mitochondria

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Ribosomes

Name : - Ribosomes , protein factories

Properties

• These are the dot like or granular structure without limiting any membrane.
• It's diameter 15nm.
• It is made up of 35% protein and 65% ribonucleic acid (RNA) called ribosomal RNA.
• Human ribosomes are 80S ('S' for Svedberg's Unit)
• Each ribosome has two subunits i.e. larger (60S) and smaller (40S)

Types of Ribosomes :

1. Ribosomes attach to the endoplsamic reticulum called rough endoplasmic reticulum (RER).
2. Free ribosome - that are distributed in the cytoplasm.

Function of Ribosomes :- 

• Rough endoplasmic reticulum :- Synthesis of protein such as enzymatic protein, hormonal protein, lysosomal protein and the protein of the cell membrane.
• Free ribosomes :- are responsible for synthesis of protein in haemoglobin, peroxisome and mitochondria.

Ribosomes

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Similar Post :- 

• Mitochondria
• Lysosomes
• Rough Endoplasmic Reticulum
• Cytoskeleton
• Cell membrane
• Golgi apparatus

Endoplasmic reticulum

Name :- Endoplasmic Reticulum (ER)

Properties :

• ER is a network of tubular and microsomal vesicular structures which is present inside the cell.
• The tubules and vesicles are interconnected.
• ER covered by a limiting membrane which is formed by proteins and bilayered lipids.
• The lumen (diameter - 400 to 700 angstrom) of ER contains a fluid medium called endoplasmic matrix.
• Total surface area of ER (in some cells like liver cells) can be as much as 30-40 times the cell membrane area.
• ER forms the link between nucleus and cell membrane by connecting them.

Types of ER ....

1. Rough Endoplasmic Reticulum (RER) / Granular Endoplasmic Reticulum (GER)
2. Smooth Endoplasmic Reticulum (SER) / Agranular Endoplasmic Reticulum (AER) / Tubular Endoplasmic Reticulum (TER)

1. RER : Rough appearance of ER is due the attachment of ribosomes (granules) to it's outer surface. Hence, it is also celled GER.

Functions :

•  Synthesis of proteins (specially those proteins which are secreted from the cells like insulin from β - cells, and formation of glycosylated proteins or glycoproteins by adition of carbohydrate with proteins).
• Degradation of worn-out organelles like mitochondria by autophagosome.

2. SER : ER with smooth appearance. It is formed by many interconnected tubules.

Functions : 

• Synthesis of non-protein substances like cholesterol, steroid hormones, lipids, phospholipids, lipoprotein and sebum etc.
• Role in cellular metabolism by it's enzymes which are present outer surface of the ER.
• Storage and metabolism of calcium.
• Catabolism and detoxification of toxic substances some drugs and carcinogens (cancer producing substances) in liver.

Similar Posts ....

• Golgi apparatus
• Cytoskeleton
• Ribosomes
• Lysosomes
• Mitochondria

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Lysosomes

Name :- Lysosomes, garbage system of the cell, suicidal bag of the cell

Properties :

1. These are membrane bound vesicular structures founds throughout the cytoplasm.
2. These are formed by the process of packaging in the golgi apparatus.
3. Enzymes of lysosomes are synthesized in rough endoplasmic reticulum.
4. Among the organelles, the lysosomes have the thickest covering membrane that is formed by a bilayered lipid material.
5. Lysosomes have 50 different hydrolytic enzymes, known as acid hydroxylases.

Types of Lysosomes :

1. Primary lysosomes, this is an inactive of form of lysosomes.
2. Secondary lysosomes, this is an active form of lysosomes (lysosomes active during phagosome or endosome and at this time lysosomes pH become acidic and enzymes are activate).

Lysosomal Enzymes : 

1. Proteases :- which hydrolyze the proteins into amino acids.
2. Lipases :- which hydrolyze the lipids into fatty acids and glycerides.
3. Amylases :- which hydrolyze the polysaccharides into glucose.
4. Nucleases :- which hydrolyze the nucleic acids into mononucleotides.

Mechanism of action :

1. Heterophagy - Digestion of extracellular material engulfed by the cell by endocytosis.
2. Autophagy - Digestion of intracellular material such as worn-out cytoplasmic organelles.

Functions : 

1. Degradation of macro-molecules, by phagocytosis or phagosome or vacuoles, and by pinocytosis or receptor mediated endocytosis or endosomes. 
2. Degradation of worn-out organelles, by autophagosomes.
3. Removal of excess secretory product in the glandular cells.
4. Secretory function (conventional lysosomes are modified into secretory lysosomes by combining with secretory granules) like...
1. Lysosomes in the cytotoxic T lymphocytes and natural killer (NK) cells secrete perforin and granzymes, which destroy both viral-infected cells and tumour cells.
2. Melanocytes secrete melanin which have protective action for skin.
3. Mast cells secrete serotonin which act as a vasoconstrictor and inflammatory mediator.

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Similar Posts :-

• Mitochondria
• Rough Endoplasmic Reticulum
• Ribososmes
• Cytoskeleton
• Cell membrane

Mitochondria

Name : Mitochondrion ( plural - mitochondria), power house of the cell.

Properties : 

• It is membrane bounded cytoplasmic organelle.
• It's shape rod or oval, and diameter 0.5 - 1.0 micrometer.
• It covered bilayered membrane 
• Outer membrane : is smooth and encloses the contents of mitochondrion as well various enzymes such as acetyl-CoA synthetase, glycerophosphate, acetyltranferase.
• Inner membrane : is folded in the form of shelf-like inward projection called cristae (crista). Cristae contain many enzymes and other protein molecules which helps in functioning. (Functions + enzymes + protein molecules in cristae = respiratory chain or electron transport chain). Enzymes of respiratory chains are 4-8 in list below.  

• It's DNA contain 37 gene.
• It responsible for maternal child relation.
• It contains many enzymes and protein.
• Increase no of mitochondria by the exercise.
• It is the site of aerobic respiration

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Enzymes and protein : 

1. Acetyl CoA synthesase.
2. Glycerol phosphate.
3. Acetyl transferase.
4. Succinic dehydrogenase .
5. Dihydronicotinamide adenine dinucleotide dehydrogenase .
6. Cytochrome oxidase.
7. Cytochrome -C
8. ATP synthase.

Functions : 

1. Self replication .
2. Production of cellular energy and synthesis of ATP (that's by known as "power house" of the cell).
3. Apoptosis 
4. Storage of calcium
5. Detoxification of ammonia in liver

Similar Posts :-

• Mitochondria
• Lysosomes
• Rough Endoplasmic Reticulum
• Cytoskeleton
• Cell membrane
• Golgi apparatus

Hemophilia

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Hemophilia 

Definition - it is a congenital disease and disorder of secondary haemolytic disease.

Cause :- congenital defect of factor VIII (anti hemophlic factor).

Clinical features :- 

1. Disease is uncommon in indians.
2. After injury bleeding stops.
3. Bleeding reappears after few minutes.
4. Continuous prolonged bleeding.

Treatment :-

1. Transfusion of blood.
2. Transfusion of plasma.
3. Transfusion of anti hemophilic factor.

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Mast cells

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Mast cells 

Mast cell present in lungs . It is a large cell and looks like basophills. They are hypersensitive to allergy and in some other conditions.

Mast cell secrets :-

1. Heparin (anti coagulant).

2. Histamine ( anti allergic).

3. Serotonin.

4. Hydrolytic enzyme.


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Clotting factors

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Clotting or coagulation factor :

1. Fibrinogen. (I)
2. Prothrombin. (II)
3. Thromboplastin or tissue factor. (III)
4. Calcium. (IV)
5. Labile factor. (V)
6. Absent... (VI)
7. Stable factor. (VII)
8. Antiheamophlic factor. (VIII)
9. Christmas factor (IX)
10. Stuart factor. (X)
11. Plasma thromboplastin anticedent. (XI)
12. Hageman factor. (XII)
13. Fibrin stablizing factor. (XIII)

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Functions of Platelets

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Functions of Platelets :

1. Help in blood clotting.

2. Haemostasis of blood.

3. Prevent clot retraction.

4. Release various substances.
5. Repairing of capillary endothelium.


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Functions of W.B.Cs

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Functions of W.B.C.

Functions of W.B.Cs

1. Phagocytosis : when bacteria and forign particles invade body, then leukocyte comes out from blood and their psedopodia process engulf and destroy them with the help of hydrolytic enzyme.

2. Antibody formation : lymphocyte are manufacture Beta and Gamma globulin. Which is a part of antibody.

3. Formation of fibroblast: leukocytes converts into fobroblast at the area of inflammation and helps in repair.

4. Manufacture of trephones : they prepare some substance from plasma proteins which have great influence on nutrition, growth and repair. These substance are known as trephones.

5. Secretion of heparin : Basophil secrets heparin which prevents from intravascular clotting.

6. Antihistamine  function : eosinophil have antihistamine or anti allergic function.


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Gastric juice

Gastric juice

1. Types of Gastric gland

2. Properties.

3. Composition.

4. Secretion.

5. Factor responsible.

6. Functions.

1. Types of gastric glands : Glands depends upon the situation -

A. Fundic/ main/proper/oxyntic gland : it secrets

1. HCL

2. Mucin

3. Pepsinogen

4. Intrinsic factor

B. Cardic gland : it secrets

1. Mucin

2. Pepsinogen

C. Pylorus gland : it secrets a solution which is rich in mucus and don't contain HCL. It also secret gastrin.

Types of cell of gastric glands : 

1. Chief or peptic cell - it produce Renin, pepsin.

2. Oxyntic or parietal cells - it produce HCL.

3. Neck mucus cells - It produce Mucus, Pepsinogen.

4. Surface epithelial cells - it produce Mucus.

5. Stem cells - it produce G- cell or Daughter cell.

6. G- cells - it produce Gastrin

Naerve supply - Vagus nerve

2. Properties : 

Volume                   - 1200 - 1500ml/day

Reaction                 - highly acidic

pH                           - 0.9 - 1.2

Specific gravity    - 1.002 - 1.004

3. Composition : 

1. Water - 99.5%

2. Solid - 0.5%...

A. Organic substances :

a. Enzymes - 
1. Pepsin.
2. Renin.
3. Gastric lipase.
4. Gastric amylase.
5. Gelatinase.
6. Urease.

b. Other organic substances -
1. Mucus.
2. Intrinsic factor.

B. Inorganic substances :
1. HCL.
2. Na.
3. Ca.
4. K.
5. Cl.
6. Bicarbonate.
7. Phosphate.
8. Sulfate.

4. Secretion : 

Phases of gastric secretion -

1. Cephalic phase :
- it contributes 33% of total gastric juice.
- it control by the nervous system (vagus nerve).
- it work in both condition ( conditional and unconditional)...
a. Conditional : sight, smell, thought and hearing about food.
b. Unconditional : presence of food in mouth.

2. Gastric phase :
- it contributes 60% of total gastric juice.
- it control nervous (vagus, local nerve) and hormonal (gastrin).
- it work when bolus come in stomach.

3. Intestinal phase : 
- it contributes 7% of total gastric juice.
- it control mainly hormonal.
- it stimulate by Gastrin.
- it inhibit by Secretin, Cholecystokinin pancreozymin, Somatostanin, Gastric inhitory peptide, Vaso active intestinal peptide.

4. Interdigestive phase : 
- it work in between two meals.
- it work only hormonal like gastrin.
Influencing factor : alcohal and caffein.

Mechanism of secretion of pepsinogen : pepsinogen is synthesized from amino acids in the ribosomes, ribosomes is attach with the endoplasmic reticulum in chief cells. Then pepsinogen granules are packed into zymogen granules by golgi apparatus. When zymogen granules secret in the stomach from chief cells then granules are desolved and pepsinogen is released. Then HCL act on this and convert into pepsin.

Mechanism of seretion of HCL : CO2 present in ECF and H2O already present in parietal cell. CO2 enter into the parietal cell and combined with H2O and form H2CO3 (carbonic acid) which are the unstable compound so early break into H + HCO3.
        Nacl present in ECF and break down into Na + Cl. Then Cl enter into the canaliculus where are already present H+, then combined H+Cl and form HCL. And HCO3 move out from the cell and combined with Na and form NaHCO3 ( sodium bicarbonate).


5. Factor responsible for gastric juice : 

1. Stimulator - Gastrin, Histamine, Vagal stimulation.

2. Inhibitor - Secretin, Gastric inhibitory polypeptide.

6. Functions of gastric juice :

1. Digestive function -

a. Pepsin : it is secret as a pepsinogen which is inactive form of this enzyme, then HCL act on this and convert into pepsin this is active form of this enzyme. Pepsin work on protein and convert into pepteose, peptone and polypeptide.

b. Gastric lipase : it is a lipolytic enzyme and convert triglycerides into monoglyceride and fatty acids.

c. Gelatinase : it convert gelatin into peptide.

d. Gastric amylase : it is a very week enzyme and work on starch.

e. Renin : it curdless milk.

2. Haemopoietic function - intrinsic factor secret from stomach and help in the absorption of vitamin B12 . This vitamin responsible for the formation and maturation of R.B.Cs.

3. Protective function - Gastric juice contain thick mucus which help to prevent
a. Irritation or mechanical injuty.
b. Action of pepsin.
c. Acidity of HCL.

4. Function of HCL - 
a. It convert Pepsinogen into Pepsin.
b. It kills the bacteria.
c. It stimulate the GIT for secretion of  hormones.


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Transport across the cell membrane

Transport across the cell membrane

The fluid which is present inside the cell membrane  known as intracellular fluid (ICF), and the fluid which is present out side the cell is known as extracellular fluid (ECF).

                  The cell membrane is present between ICF and ECF. This cell membrane is semipermeable and it allows selective molecules through it.

Transport across cell membrane 

Process : the movement of substances across cell membrane by following two process...
1. Passive transport
2. Active transport

Passive transport : use own energy , no ATP use.

Types : 

1. Diffusion :
Definition - a process in which solute move from higher concentration area to lower concentration area known as diffusion.

Diffusion are two types...

A. Simple diffusion : in which

a. Lipid layer of cell membrane which is known as simple lipid diffusion. This layer is permeable to lipid soluble substances like oxygen and carbon dioxide.

b. Protein layer of cell membrane which is known as protein diffusion. This layer is permeable to water soluble substances like electrolytes.

Diffusion  through channels : cell membrane have small pores which are selective permeable in nature called channels . When the cell is resting condition than channel remain closed, when the cell is functioning than channels are opened.

a. Voltage gated channel : when channel are open   by electrical impulses called voltage gated channel.

b. Ligand gated channel : when channel opens by the chemical stimulus are known as ligand gated channel.

B. Facilitated / carrier mediated diffusion : in this process transport occur with the help of carrier protein.

2. Osmosis : when water move from low solute concentration to high solute concentration.

Active transport : movement of substances from lower concentration to higher concentration .and required energy in the form of ATP.

Types:

1. Primary active transport : in this process the energy is directly obtained from the ATP.
Like - a. Na+ - K+ (Na - K pump)
           b. Ca+ (Ca pump)
           c. K+ - H+ (K - H pump)

2. Secondary active transport : this process in which energy use indirectly (created by primary active transport). It is mainly two types...

A. Co transport  : when two molecules move in same direction is known as co transport.

Requirements for the co transport - 
a. Primary active transport for indirect energy.
b. Carrier protein.
c. Sympoters - (Na + Glucose, Na + Amino acids ).

Main side:  a. Intestinal epithelium.
                      b. Renal tubules of the kidney.


B. Counter transport  : when two molecule move in different direction.

Requirements for the counter transport  -
a. Anti porters - two molecule attach with same carrier protein in different direction. like Na - H, Na - Ca.
b. Carrier protein.
c. Primary active transport  for indirect energy.

Main side:  a. Proximal convoluted tubule (PCT) - for Na - H, Na - Ca.


3. Vesicular active transport : it is following two types...

a. Endocytosis.
b. Exocytosis.

Endocytosis and exocytosis

A. Endocytosis : Macro molecule are very large in shape so they can't enter the cell, then they enters the cell by the process  of endocytosis.

Types:  these are three types...

a. Pinocytosis / cell drinking : it is the process by which macro molecule like bacteria, antigens enters into the cell.

Mechanism -
                      -Macro molecule attach to the surface of cell.
                      -Now cell membrane evaginate around the macro molecule.
                      -Now cell membrane engulf it.
                      -Macro molecule convert into vesicle (known as endosome) .
                      -Now hydrolytic enzyme destroy them.



b. Phagocytosis / cell eating : in this process through which particles enter the cell. The cell which perform the function of phagocytosis are known as phagocytes

Types of phagocytes -

1. Polymorphonuclear ( Neutrophil or Microphages)
2. Macrophages or monocytes

Stages : 

a. Attachment or opsonisation : generally phagocytes and micro organism have negatively charged. Due to this negative charge repel each other.
        Now phagocytes will become positively charged and will convert into opsonin than attach to micro organism.

b. Engulfment : Now it will formed pseudopod, by this ( pseudopod) easily engulf micro organism or other materials.

c. Secretion : Now W.B.C. will secret hydrolytic enzyme, which act on foreign particles.

d. Degradation or killing : Now micro organism will be destroyed by hydrolytic enzyme.

c. Receptor mediated endocytosis : it is transport of macro molecule with the help of receptor protein

Structure:  the surface of cell membrane contain a pit. This pit have receptor protein known as clathrin. Pit and clathrin together known as receptor coated pit  which help in endocytosis.

Mechanism - material bind with the receptor and formed a complex known as receptor material complex .

B. Exocytosis : it is the process by which a substance comes out of a cell.
It is the opposite phenomenon of endocytosis.

Mechanism : -Macro molecule convert into vesicle (known as exosome).
-Macro molecule attach to the surface of the cell.
-Now cell membrane evaginate the macro molecule.
-Now macro molecule comes out of the cell.


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Functions of gall bladder

Functions of gall bladder

a. The bile secreted from liver and stored in gall bladder. 

b. Gall bladder is not essential for life. 

c. The removal of gall bladder called cholecystectomy. 

d. After cholecystectomy ,patients does not suffer from any major disadvantage. 

e. In some species gall bladder is absent.

Functions: -

1. Storage of bile.

2. Alteration of pH of bile.

3. Secretion of mucin.

4. Maintenance of pressure in biliary system.

Gallbladder 

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Cell

Cell

Cell means small room or a chamber. Cell word was given by Robert Hook in 1663 and cell discovered also in 1663 by Robert Hook.

Definition : cell are the structural and functional unit of a living body. These are the smallest unit which contains all the features of life.

General features of cell : 

1. Cell required Oxygen, nutrition for their survival.

2. Cell can produce own energy itself, which is important for their Growth, Repair, Activities.

3. Cell produce carbon dioxide and other metabolic waste products during his activities.

4. Cell shows immediate response against bacteria, viruses or toxic substances entering in the body.

5. Cell reproduced through cell division except neurons and cardiac muscle fibers.

Structure of a cell : a cell contains...

• Body
• Cell membrane

1. BODY 

• Nucleus
• Cytoplasm

    A. Nucleus : it is covered by a double layer membrane known as nuclear membrane.
Nucleoplasm : it is a gel like substance which is stored in nucleus.

Nucleus contain : 
a. D.N.A. : gene 30000 (23 pairs of chromosomes).
b. R.N.A. :

Types of R.N.A. :
1. mR.N.A. ( messenger R.N.A.)
2. tR.N.A. (transfer R.N.A.)
3. rR.N.A. (ribosomal R.N.A.)

Nucleoli : it is present in nucleus which contains R.N.A. and some proteins.

Functions of nucleus : 
1. It is the centre of all activities of cell.
2. Genes are present here which controls the cell division.
3. Genes transfer the hereditary information's of a species from one generation to another.

    B. Cytoplasm : it is the fluid which is present inside the cell. It contains...

1. Clear fluid.

2. Particles :
                   a. carbohydrate
                   b. protein
                   c. fats

3. cell organelles...

Types of cell organelles : 

1. Membrane bounded :

a. Endoplasmic reticulum.

b. Golgi apparatus : delivers proteins molecules to different part of the cell.

c. Lysosomes : contains enzymes formed by endoplasmic reticulum.

d. Peroxisome : help in glucogenesis, intoxication of peroxide.

e. Vesicles : release secretary substances.

f. Mitochondria : power house of the cell which stores energy.

2. Not bounded by membrane :
a. Chromosome.

b. Ribosome : synthesis of protein.

c. Microfilaments : transport system of the cell.

d. Microtubules : Give strength to the cell.

Parts of cytoplasm : 

a. Ectoplasm: Peripheral part of cytoplasm, situated just beneath the cell membrane.

b. Endoplasm: Inner part of cytoplasm, interposed between the ectoplasm and the nucleus.


2. CELL MEMBRANE : it is the protective covering of the cell body. It separate ICF from ECF. It is a semipermeable membrane which help to exchange certain substances between ICF and ECF.

Thickness  - 75 -111°A

Composition of cell membrane : 

1. Protein - 55%

2. Lipid - 40%

3. Carbohydrate - 5%

Classification of cell membrane on the basis of presence of above substances...

1. Unit membrane.

2. Double layer membrane.

3. Triple layer membrane.

Functions of cell membrane :

1. Protection.

2. Semi permeability.

3. Absorption.

4. Excretion.

5. Exchange of gases.

6. Maintain the shape of cell.

7. Maintain the size of cell.

Cell

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Similar Posts :-

• Mitochondria
• Lysosomes
• Rough Endoplasmic Reticulum
• Cytoskeleton
• Cell membrane
• Golgi apparatus

Anterior abdominal wall

Anterior abdominal wall

Anterior abdominal wall is made up by the skin, ( outer to inner) superficial fascia, muscles, nerves, lymph, vessels. It starts from 9 T.V. to pubic symphysis.

Blood supply : 

Epigastric artery, Deudenal artery and superficial circumflex.

Download  book:  Anatomy vol-2 BD chourasia (Lower limb, Abdomen and pelvis).

Muscles of anterior abdominal wall -

1. External oblique abdominis -

Origin : external surface & inferior border of the ribs with eight slips.

Insertion : xiphoid process, linea Alba, pubic symphysis, pubic crest, pectineal line of the pubis, iliac crest.

Action : forward bending, rotation, abduction.

Nerve supply : T7 - T12

2. Internal oblique muscle -

Origin : inguinal ligament 2/3, iliac crest 2/3, thoracolumbar fascia.

Insertion : 10-12 ribs

Action : bilateral contraction, compress the abdomin, unilateral contraction, ipsilaterally rotates the torso.

Nerve supply : T7 - T12, branches of lumbar plexus.

3. Transverse abdominis -

Origin : inguinal ligament 1/3, costal cartilage 7-12, iliac crest 1/3, thoracolumbar fascia 1/3.

Insertion : pubic crest, conjoint tendon, xiphoid process, linea Alba.

Action : compression of abdominal contents.

Nerve supply : T7 - T12, branches of lumbar plexus.

4. Rectus abdominis (long, paired) -

Origin : pubic crest.

Insertion : xiphoid process, costal cartilage of 5-7th ribs.

Action : assisting to flat muscles in compressing the abdominal viscera. Rectus abdominis also stabilise the pelvis during walking and depresses the ribs.

Nerve supply : T7 -T11

5. Pyramedialis (small, triangular) -

Origin : pubic crest, pubic symphysis.

Insertion : linea alba.

Action : it tense the linea alba.

Nerve supply : T12

6. Cremaster muscle - 

Origin : inguinal ligament.

Insertion : tunica vaginalis.

Action : raise and lower the scrotum.

Nerve supply : genital branch of genitofemoral nerve.

Related books...

Download  book:  Anatomy  vol-1 BD chourasia (Upper limb and  Thorax).

Download  book:  Anatomy  vol-3 BD chourasia ( Head , Neck and Brain).

Self assessment and review of Anatomy  by Rakesh k kaushal

Abdominal regions

Abdominal region

The abdomen is a large area so for the study purpose it split into nine region by two horizontal plane and two vertical plane.

Horizontal plane - 

1. Transpyloric plane : a horizontal line, halfway between xiphoid process and the umblicus, passing through the pylorus of the stomach.

2. Inter tubercular plane : a horizontal line which joined to iliac crest each other.

Vertical plane -

This plane run form the mid clavicle to the mid inguinal point these plane are mid clavicular line. That is two in no right and left.

Download  book: Anatomy  vol-2 BD chourasia ( Lower limb, Abdomen and pelvis ).

 Regions -

1. Right hypogastric region - Viscera : Liver, gallbladder.

   

Abdominal regions

2. Epigastric region - Viscera : stomach, duodenum, pancreas, liver.

3. Left hypochondric region - Viscera : stomach, spleen, left colic flexure, Liver.

4. Right lumbar region - Viscera : Right kidney, ureter, ascending colon.

5. Umblical region - Viscera : aorta, stomach, coil of small intestine, inferior vena cava.

6. Left lumbar region - Viscera : left kidney, ureter, descending colon.

7. Right iliac fossa - Viscera : caecum, vermiform appendix.

8. Hypogastric region - Viscera : urinary bladder, coil of small intestine, uterus.

9. Left iliac fossa - Viscera : sigmoid colon.


Related books...

Download  book: Anatomy vol-1 BD chourasia ( Upper limb and Thorax ).

Download  book: Anatomy  vol-3 BD chourasia ( Head, Neck and Brain) .


Self assessment and review of Anatomy  by Rakesh k kaushal