THE MUSCULAR TISSUE & THE LYMPHOID TISSUE PRE-LAB.6. BY PROF. DR. ANSARI Friday, June 17, 2022
Jan 29, 2016
THE MUSCULAR TISSUE &
THE LYMPHOID TISSUEPRE-LAB.6.
BYPROF. DR. ANSARI
Saturday, April 22, 2023
The objectives
• To know the histological structure of muscular tissue.
• To differentiate between the smooth muscle, skeletal muscle & cardiac muscle microscopically.
• To learn the histology of various lymphoid organs.
• To distinguish one from the other lymphoid organs histological.
Saturday, April 22, 2023
SKELETAL- SMOOTH – CARDIAC MUSCLES
Saturday, April 22, 2023
Features of muscular tissue• Cells are called as myocytes, occur as sheets or
fibers.• The tissue possess the contractile elements, actin
and myosin proteins.• They show regular and irregular arrangements of
actin and myosin filaments.• Skeletal and cardiac muscles show birefringence,
or striated in nature.• There is no mitosis in skeletal and cardiac
muscles hence no regeneration.
Saturday, April 22, 2023
Skeletal muscle
• It is striated muscle fibers.• Multinucleated & nuclei are peripherally
situated.• It is voluntary muscle, also called as skeletal
muscle.• It show striations in their cytoplasm, these are
due to alignment of actin and myosin filaments in register.
Saturday, April 22, 2023
Observe the alternate dark and light bands & peripherally situated multiple nuclei
Saturday, April 22, 2023
This is a longitudinal Section of skeletal muscle fibers
The connective tissue over the muscular tissue
• Perimysium is a layer of connective tissue around the muscle .
Saturday, April 22, 2023
Endomysium
• loose connective tissue called "endomysium" surrounds each muscle fiber.
Saturday, April 22, 2023
Epimysium
• It is a layer of connective tissue enwrapping the whole muscle.
Saturday, April 22, 2023
Saturday, April 22, 2023
In a T.S. of skeletal musclethe nuclei are peripherally situated
Saturday, April 22, 2023
Smooth muscle1. Smooth muscles are found in the walls of blood vessels, stomach, intestines, uterus and urinary bladder .2.The muscle fibers are spindle shaped.3. A large oval shaped nucleus is situated centrally in the spindle shaped smooth muscle fiber.4. No striations are seen in these muscle fibers.
Saturday, April 22, 2023
Cardiac muscle
• It is striated muscle.• It is involuntary muscle.• It is seen in heart.• It shows intercellular cell junctions, called as intercalated disks.• The cardiac muscles show branching fibers.• The nucleus is situated centrally.
Saturday, April 22, 2023
Saturday, April 22, 2023
Saturday, April 22, 2023
In T.S. ofCardiac muscleNuclei are centrally situated
In T.S. ofCardiac muscleNuclei are centrally situated
Purkinje fibersAre specializedCardiomyocytesWith pale cytoplasm& central nucleus
Purkinje fibersAre specializedCardiomyocytesWith pale cytoplasm& central nucleus
Lymphoid organs
• Palatine tonsil are situated in the oral cavity• Thymus is situated in the neck and superior
mediastinum.• Lymph nodes are situated in the neck, axilla,
groin, & abdomen• Spleen is located in the left hypochondrium.• These organs protect us from foreign invaders,• They form second line of defense.
Saturday, April 22, 2023
Saturday, April 22, 2023
Microscopically palatine tonsil
• The epithelial lining is nonkeratinizedStratified squamous.A crept is an identifying feature of tonsil.A lymphoid nodule is Also a lymphoid feature.
Saturday, April 22, 2023
Lymph node
• A lymph node has a hilum, where blood vessels enter and leave.
• It has a capsule covering.• It has a cortex and medulla zones.• It shows a sub cortical sinus.• It has Lymphoid follicles in cortex.• The Para cortex is deep cortex having “T”
lymphocytes.• The germinal centers have “B” lymphocytes.
Saturday, April 22, 2023
Saturday, April 22, 2023
Medulla
• The following sinuses are seen in lymph node:-
• Sub capsular sinus• Trabeculae sinuses• Medullary sinuses.
Saturday, April 22, 2023
1. Dense connective tissue capsule2. Dense connective tissue trabeculae 3. Cortex3a. Cortical nodules with germinal centers 3b. Para cortex 4. Medulla 4a. Medullary cords4b. Medullary sinus5. Sub capsular sinus
1. Dense connective tissue capsule2. Dense connective tissue trabeculae 3. Cortex3a. Cortical nodules with germinal centers 3b. Para cortex 4. Medulla 4a. Medullary cords4b. Medullary sinus5. Sub capsular sinus
Thymus• Microscopically thymus section shows the characteristic thymic corpuscles, Hassel’s corpuscles.• It is the source for “T” lymphocytes.Cortex is darkly stainedMedulla is pale in appearance.
Saturday, April 22, 2023
Saturday, April 22, 2023
Spleen• It is the largest lymphoid
organ.• Microscopically it shows
“white pulp & Red pulp”.• Red pulp is due to blood
vessels.• White pulp is due to
lymphoid tissue.• Eccentrically situated
efferent arteriole is a special feature of spleen corpuscles.
Saturday, April 22, 2023
Applied anatomy• Myasthenia gravis is a disease of weakness of
muscle.• Duchene's muscular dystrophy is a degenerating
congenital disorder of muscular system.• Tonsillitis is an inflammation and infection of
palatine tonsils.• Lymph nodes are involved in spread of cancer.• HIV virus will damage “T” lymphocytes. • In myocardial infarction there is damage to
cardiac muscles.
Saturday, April 22, 2023