GENZOOLAB ACT3A Forms of Cells

Summary

The lecture explores the diverse shapes of cells and their associated functions in the human body. Dr. Nicor Spine, the instructor, discusses 12 cell types, including spherical, oval, cuboidal, squamous, and columnar, each specialized for specific tasks like transport, absorption, and movement. Examples include red blood cells, sperm cells, and neurons. The lecture also covers specialized cells like ciliated columnar cells, muscle cells, and nerve cells, emphasizing how a cell's shape supports its role, such as transmitting signals or aiding in movement. The session ends by highlighting the importance of cell structure in function.

Takeaways

• 🧬 Cells come in various shapes, each tailored to their specific function within the body.
• 🔴 Spherical cells, like red blood cells and human egg cells, are designed for transport of materials, nutrients, and gases.
• 🐸 Oval-shaped cells include human sperm cells and frog erythrocytes, aiding in movement through reproductive or circulatory systems.
• 🟦 Cuboidal cells, commonly found in kidney tubules and salivary glands, are specialized for storage.
• 📏 Squamous cells, flat and square-like, are present in the outer layer of skin, aiding in protection.
• 🔬 Columnar cells, which are taller than they are wide, are found in the intestines, enhancing absorption due to their structure.
• 🌬️ Ciliated columnar cells, found in the respiratory tract, help with air filtration and transport using tiny hair-like structures (cilia).
• ⚖️ Polygonal cells, like adipocytes (fat cells), form tissues found in structures like mammary glands, storing fat.
• 💪 Cylindrical cells, such as those in skeletal and cardiac muscles, are specialized for contraction, with striations in skeletal muscles and branching fibers in cardiac muscles.
• 🌟 Stellate (star-shaped) cells, like neurons, are designed to transmit signals via axons and dendrites.

Q & A

What is the main purpose of different cell shapes in the body?

The shape of a cell is directly related to its function in the body. Different shapes allow cells to perform specific tasks, such as transportation, absorption, or contraction.

Why are red blood cells and human egg cells spherical in shape?

Red blood cells and human egg cells are spherical in shape to facilitate transport. Red blood cells transport nutrients and gases, while human egg cells move through the reproductive tract for fertilization.

What is the function of cuboidal cells, and where are they commonly found?

Cuboidal cells are primarily involved in storage and secretion. They are commonly found in kidney tubules and salivary glands.

How do columnar cells in the intestines enhance absorption?

Columnar cells in the intestines increase the surface area for absorption through structures called microvilli, which help the body absorb nutrients more efficiently.

What is the difference between regular columnar cells and ciliated columnar cells?

Regular columnar cells are longer than they are wide and are found in areas like the intestines. Ciliated columnar cells have hair-like extensions (cilia) and are found in the respiratory tract, helping filter and transport air.

What are adipocytes, and what is their shape?

Adipocytes are fat cells, and they have a polygonal shape. They form adipose tissue and can be found in various parts of the body, including the mammary glands.

What cell shape is found in skeletal and cardiac muscles, and what is its purpose?

Skeletal and cardiac muscle cells have a cylindrical shape. They are designed for contraction, with skeletal muscle attached to bones and cardiac muscle found in the heart.

What is the unique feature of cardiac muscle cells compared to skeletal muscle cells?

Cardiac muscle cells have branching fibers and a structure called intercalated discs, which allow for rhythmic, coordinated contraction in the heart.

What is the function of stellate (star-shaped) cells, and where are they found?

Stellate cells, or neurons, are responsible for transmitting electrical impulses throughout the nervous system. They have extensions called dendrites and axons for sending and receiving signals.

What is the role of pseudopodia in amorphous cells, and what process do they assist with?

Pseudopodia, or 'false feet,' are extensions that allow amorphous cells, like lymphocytes, to move and engulf bacteria during phagocytosis. This helps in immune defense by digesting harmful invaders.