Tissues and Cell Types Overview

Tissues Formation

• Tissues are formed when cells group together to perform a common function.
• The type of cells determines the tissue's nature and function.
• Tissues form organs, and organs work together to form organ systems.

Epithelial Cells

• Found in the skin, the largest organ in the body.
• Protect the body from the external environment and cover internal organs.

Muscle Cells (Myocytes)

• Responsible for movement.
• Classified based on texture, attachments, and responsiveness.

Striated Muscle Cells (Skeletal Muscle Cells)

• Perform locomotory functions like exercise.
• Connected to bones, enabling movement through muscle contraction.

Smooth Muscle Cells

• Found in the muscles of internal organs.

Cardiac Muscle Cells

• The most powerful muscle cells.
• Responsible for pumping blood throughout the body.

Bone Cells (Osteocytes)

• The most resilient body cells.
• Bound together by calcium and phosphate.
• Provide strength, support, and framework to the body by enclosing organs.
• Form bones and work with striated muscle cells to enable locomotion.

Cartilage Cells (Chondrocytes)

• Similar function to bone cells but softer and more flexible due to chondroitin sulfate.
• Surrounded by spaces called lacunae, allowing for bending.
• Found in ears and cover the ends of long bones to reduce friction at joints.

Nerve Cells (Neurons)

• The most versatile cells, operating constantly throughout life.
• Found throughout the body.
• Enable thinking, feeling, and responding to the environment.
• Long with branches at both ends, some can grow up to several meters long.
• Consist of dendrites (receive signals) and axons (convey messages).
• Make up the brain and spinal cord.
• Do not multiply after birth.

Secretory Cells

• Found in glands, which secrete substances.
• Secretions can include sweat, oil, and other substances that play important roles in the body.

Adipose Cells (Fat Cells)

• Ring-like in form, function to store fat.
• Contain a droplet of lipid surrounded by cytoplasm.
• Found in the abdomen and buttocks.
• Reduce friction and cushion the body.

Blood Cells

• Red blood cells (erythrocytes): Transport oxygen to the body.
• White blood cells (lymphocytes, monocytes, neutrophils, eosinophils, basophils): Protect against infection.
• Thrombocytes (platelets): Help with blood clotting to prevent blood loss.

Reproductive Cells (Gametes)

• Have a single set of chromosomes.
• Become active at puberty.
• The nucleus of the spermatocyte (male gamete) unites with the nucleus of the oocyte (female gamete) during fertilization to form a new organism.