Eukaryotic Cells and Organelles

Eukaryotic Cell

• Eukaryotic cells are complex cells found in higher plants and animals.
• They form multicellular bodies and are also characteristic of protozoa like amoeba and malaria parasites.
• Eukaryotic cells consist of a nucleus and cytoplasm, surrounded by a plasma membrane.
• The nucleus is enclosed by a nuclear envelope and contains chromosomes and the nucleolus.
• The cytoplasm contains membrane-bound and non-membrane-bound organelles, and cytoplasmic inclusions.

Cell Organelles (from diagram)

• Cell membrane
• Smooth endoplasmic reticulum
• Nuclear pore
• Nucleoplasm
• Nuclear envelope
• Rough endoplasmic reticulum
• Mitochondrion
• Golgi apparatus
• Secretory vesicles
• Cytoplasm
• Centrosome
• Peroxisome

Human Body and Cells

• To understand human body morphology, knowledge of cells, tissues, organs, and systems is necessary.
• Studying the microscopic (histological) structure of cells is essential.
• The macroscopic appearance (gross) of organs and systems, their location, and relations, must also be understood.

Cell Biology (Cytology)

• Cytology is the study of individual cells.
• It involves recognizing different cell types and understanding their organization and structure in relation to their functions.

Histology

• Histology studies the morphological features of cells and their arrangements in tissues and organs.
• In histology, the tissue or organ part to be studied is referred to as a specimen.
• Specimens used in histology often come from animals with similarities to human tissue.

The Cell: General Overview

• The cell is the smallest living unit of the human body.
• Cells combine to form tissues, tissues to form organs, and organs to form systems.
• The cell is made up of three main compartments: nucleus, cytoplasm, and plasma membrane.

Cell Variations

• Mammalian cells vary in size, shape, and function.
• Different cells have various shapes and sizes within the body.
• Studying cells is essential to understand their functional differences in tissues and organs.

Types of Cells

• There are two main types of cells: prokaryotic and eukaryotic.
• Prokaryotic cells are primitive, unicellular, generally small, and lack a nucleus. Their hereditary material is free in the cytoplasm.

Prokaryotic Cells (additional details)

• They have few or no organelles.
• Membrane-bound organelles are absent.
• They replicate quickly by binary fission.

Types of Cells - examples

• Neurons: Initiate and conduct nerve impulses.
• Muscle cells: Responsible for contraction and peristalsis, enabling movement.
• Glandular cells: Secrete hormones, enzymes, and growth factors.
• White blood cells: Recognize and eliminate pathogens.
• Oligodendrocytes and Schwann cells: Myelinate nerve axons.
• Osteoblasts: Form bone tissue.
• Osteoclasts: Destroy bone tissue.
• Adipocytes: Store fat.
• Fibroblasts: Facilitate wound healing and tissue repair.
• Monocyte, Lymphocyte, Neutrophil, Eosinophil, Basophil, Macrophage, Erythrocyte, Platelets: Different types of blood cells with specific functions.

Specialized Cells and Functions

• Different cells have specialized functions.
• These lead to morphological differences.
• Cells need external sources of nutrients and oxygen for survival.
• Nutrients provide energy and build new molecules.

Types of Muscle Cells (diagram)

• Cardiac muscle cells
• Skeletal muscle cells
• Smooth muscle cells