Lesson 1 - Cell The Foundation Of Life PDF

 DIAGNOSTIC TEST What makes plant cell different from animal cell? Correct Answer: A A. Plant cell have cell wall B. Plant cell have cell membrane C. Plant cell undergo the process of cell division D. Plant cel...

 DIAGNOSTIC TEST What makes plant cell different from animal cell? Correct Answer: A A. Plant cell have cell wall B. Plant cell have cell membrane C. Plant cell undergo the process of cell division D. Plant cell contains different organelles responsible for cellular activities  DIAGNOSTIC TEST Looking at unknown specimen, you observed that it has a cell wall, surrounding different cellular organelles inside. What can you conclude on the characteristics of the cell based on your observation? Correct Answer: D A. It is an animal cell B. It belongs to a bacterial cell C. The characteristics belongs to a plant cell D. It’s hard to tell, unless other cell parts are also mentioned  DIAGNOSTIC TEST The following is true about the nucleus except for one. Which is the exception? Correct Answer: B A. It contains the genetic material B. It is the control center of the cytoplasm C. It controls all metabolic and cellular activities D. It is a dense body inside the cell that holds the DNA for inheritance  DIAGNOSTIC TEST Whichof the following organelles is unique within an autotrophic, eukaryotic cell? Correct Answer: C A. Chromatin B. Cytoplasm C. Chloroplast D. Cell membrane  DIAGNOSTIC TEST Based on the tenets of the cell theory, which of the following does not belong to the group? Correct Answer: D A. Animals B. Bacteria C. Plants D. Viruses 1. Explain the postulates of the cell theory 2. Describe the structure and function of major and subcellular organelles 1. Trace the historical development of the cell leading to cell theory 2. Determine the structure and function of the cell 3. Perform an experiment involving plant and animal cell  It comes from two Greek words such as: Bio meaning “life” Logos meaning “study of” It is the branch of natural science dealing with the study of life. Botany Anatomy & Phycology Physiology Mycology Microbiology Bacteriology Histology Entomology Herpetology Zoology Parasitology Ichthyology Cytology Mammalogy Morphology Embryology Ecology Ornithology Genetics  The basic functional unit Types of cell Living things of all organisms, carrying the DNA that Prokaryotic cell contains the instruction Eukaryotic cell CELLS for all cell activity Unicellular Multicellular Single-celled Organism with organism many cells DID YOU KNOW? Not everything that seems to be alive or living are actually alive. Viruses do not meet the essential criteria for life as defined by self- maintenance and independent replication. They exist in a gray area, being crucial to biological processes and evolution but lacking the autonomous functions that characterize living organisms. Thus, under current scientific understanding, viruses are not classified as a living organism. CHARACTERISTICS OF LIFE 1. Organization or Order 2. Reproduction 3. Response to Stimuli or Sensitivity 4. Homeostasis or Balance 5. Growth and Development 6. Adaptation 7. Metabolism CHARACTERISTICS OF LIFE ORGANIZATION In order be considered living, all individuals in the biosphere must follow the biological levels of organization, where the concept of life emerges or starts only from the CELL. CHARACTERISTICS OF LIFE REPRODUCTION A living individual should be able to produce or make a copy of itself whether through sexual or asexual processes. A cell during reproduction - mitosis CHARACTERISTICS OF LIFE RESPONSE TO STIMULI Living individual should have the ability to develop sensitivity to their environment, leading to an appropriate response to a given situation. Responding to a certain situation CHARACTERISTICS OF LIFE HOMEOSTASIS Living individual should have the ability to maintain an internal equilibrium when dealing with external changes. Sweating balances the temperature inside and outside the body, leading to homeostasis CHARACTERISTICS OF LIFE GROWTH & DEVELOPMENT Living individual should have the ability to change, gain an increase in their body structures, and develop during the span of their life. Plants growing and developing during their entire life span CHARACTERISTICS OF LIFE ADAPTATION Livingindividual should evolve to adapt or be fit in the continuously changing environment. Different species of eagle have evolved because of the influence of different environmental pressures CHARACTERISTICS OF LIFE METABOLISM Livingindividual should have the ability to build- up and break down complex molecule inside their body. Food materials are broken down into simple molecules in the digestive system If viruses are not classified as living organism, how come they were able to replicate hundreds to millions of copies of themselves?  ROBERT HOOKE In 1665, Robert Hooke discovered and coined the term cell as observed from a bark of an oak tree. He used the word cell to describe the tiny compartments seen on the specimen. He presented this idea in his best- selling book the “Micrographia”.  ANTON VAN LEEUWENHOEK In 1674, Leeuwenhoek was the first to use the microscope and observe a living cells, specifically protozoa and bacterial cell.  ROBERT BROWN In 1831, Robert Brown observed and described a small, dense, round body within a plant cell, which he called the "nucleus” that is later identified as the control center of the cell, holding the genetic material of an organism. An illustration and actual photo of the cell’s nucleus as observed under electron microscope Reference: Keller, S., & Marieb, E. (2018). “Essentials of Human Anatomy & Physiology 12th Edition. Pearson Education Inc., 330 Hudson St., New York, New York City, USA, 10013  FELIX DUJARDIN In 1835, Felix Dujardin discovered the fluid content of the cell and called it “sarcode” which was later identified as protoplasm by J.E Purkinje in 1839, containing the cytoplasm, nucleus, and the organelles.  MATTHIAS SCHLEIDEN In 1838, Matthias Schleiden concluded that all plant tissues are composed of cells. He emphasized that the cell is the fundamental unit of structure and function in plants. An illustration and actual photo of the plant cell under the microscope Reference: Clark, M., Choi, J., Douglas, M. (2020). Biology 2E. Rice University, 6100 Main Street MS-375, Houston, Texas 77005  THEODOR SCHWANN Theodor Schwann, extended Schleiden's findings to animals in 1839. He concluded that all animal tissues are also composed of cells, establishing that cells are the basic unit of life in both plants and animals. Reference: Keller, S., & Marieb, E. (2018). “Essentials of Human Anatomy & Physiology 12th Edition. Pearson Education Inc., 330 Hudson St., New York, New York City, USA, 10013  CARL HEINRICH BRAUN In 1845, Carl Heinrich Braun emphasized that cells are not just the basic unit of structure and function but also the fundamental unit of life of an organism. This idea helped solidify the understanding that life processes starts at cellular level.  RUDOLF VIRCHOW In 1855, Rudolf Virchow observed that a cell can only occur from another cell through cell division, debunking Aristotle’s widely accepted notion of spontaneous generation. Animal cell making a copy of itself through the process of cell cycle and reproduction TENETS OF THE CELL THEORY 1. All living things are made up of one or more cells and its metabolic reactions takes place in the cell. 2. Cells arise from pre-existing cells. 3. Cells is the basic, functional, and fundamental unit of life. GROUP ACTIVITY Labeling the Organelles of the Cell  12 11 1 Animal Cell 10 Smooth Endoplasmic Reticulum 9 Rough Endoplasmic Reticulum Cell membrane 8 Mitochondria Cytoskeleton Golgi Body Cytoplasm 2 Nucleolus Lysosome 7 3 Centriole Vesicle 4 Nucleus 6 5  12 11 Plant Cell 1 10 Smooth Endoplasmic Reticulum Rough Endoplasmic Reticulum 9 2 Cell membrane Mitochondria Chloroplast 8 3 Golgi Body Cell wall Nucleolus 4 Lysosome Vacuole 5 7 Vesicle Nucleus 6  10 9 Bacterial Cell 8 Cell membrane 7 Plasmid DNA Food granule 6 1 Ribosomes Cytoplasm Flagellum 2 Nucleoid Capsule 3 Cell wall 5 4 Pili PRINCIPAL COMPONENT OF THE CELL The cell’s structure is primarily divided into three distinct principal parts through which different cellular organelles are located. 1. Cell or Plasma membrane 2. Cytoplasm 3. Nucleus  PLASMA MEMBRANE The semi-permeable lipid bilayer structure of the cell that regulates the entry and exit of materials inside and outside the cell, and maintain the cell’s integrity. Figure: Structure of the Plasma membrane  NUCLEUS Nucleus is a dense body within a cell that control all of its cellular activity. It contains the DNA that stores information and directs genetic transfer. It is known as the control center of the cell. PARTS OF THE NUCLEUS Nucleolus is a dark region inside the nucleus containing ribosomal RNA and protein. It is responsible for the synthesis of ribosome. Nuclear pores are small opening in the nuclear envelope that regulates the movement of substances in and out of the nucleus. PARTS OF THE NUCLEUS Nuclear envelope is the boundary of the nucleus, composed of the inner and outer nuclear membrane. Nucleoplasm is a fluid-like component of the nucleus in which the nucleolus and chromatin fibers are suspended. PARTS OF THE NUCLEUS Chromatin are the thread- like structure inside the nucleus that condenses during cell division and forms chromosomes. The coiled structure seen in a chromosomes are actually the genetic material called the “DNA” that carries information for inheritance. CYTOPLASM Separating the cell membrane and the nucleus is the cytoplasm, where most cellular activity takes place Composed of fluid-like structure called the cytosol, filling most of the cell, through which membrane- bound organelles are suspended. This is where most cellular activity takes place. MITOCHONDRIA A membrane-bound organelle in the cytoplasm responsible in converting food and oxygen into ATP, the energy currency of the cell. Commonly known as the “Powerhouses of the Cell.” RIBOSOME Ribosomes are tiny, dark bodies made of protein and ribosomal RNA whose function is to produce protein for different cellular activities. Ribosome is the actual site of protein synthesis, located in the nucleolus or attached to Rough Endoplasmic Reticulum. ENDOPLASMIC RETICULUM Itis the biosynthetic factory and shipper of cell products. This is where protein and other molecules are being transported from one part of the cell into another. There are two types of ER. One is smooth and the other is rough endoplasmic reticulum. Rough ER: Organelle where most ribosomes are attached to it, rendering a granular appearance. Smooth ER: Functions in lipid metabolism (cholesterol and fat synthesis and breakdown) and detoxification of drugs and pesticides. GOLGI APPARATUS It is the packaging counter of the cell. Its major function is to modify, package, and ship proteins (sent to it by the rough ER via transport vesicles) in specific ways, depending on their final destination. GOLGI APPARATUS Figure: The illustration shows how the Golgi apparatus perform its function inside the cell LYSOSOMES It is the suicide bag of the cell. It contains powerful hydrolytic enzymes that breaks down waste product and old worn- out cell parts. It is abundant in the phagocytes, disposing foreign substances that enters the body. CYTOSKELETON It is the framework of the cell. It serves as the bone and muscle of the cell that is crucial in moving cellular components and give cell its shape. Three Classifications of Cytoskeleton 1. Microfilament - Involved in muscle contraction and other types of intracellular movement 2. Intermediate filament – resist mechanical forces acting on the cell 3. Microtubules - Support the cell and give it shape. Involved in intracellular and cellular movements. Figure: The illustration shows the different framework inside the cell comprising the cytoskeleton CENTROSOMES & CENTRIOLES It is a microtubule organizing center, consisting of a granular matrix and centrioles - a pair of barrel-shaped microtubular organelles that lie at right angles to each other. Centrioles aid in cell division by producing spindle fiber, pulling sister chromatids towards different poles. CENTRIOLES SPINDLE FIBERS CILIA AND FLAGELLA Cilia and flagella are cellular extensions responsible for the locomotion of cells. Protist like paramecium moves through cilia A sperm swim through their flagellum There are several organelles that only exists in plants and bacteria. Such organelles are: ORGANELLE PLANTS BACTERIA Cell wall Present Present Chloroplast Present Present in some Central vacuole Present Absent Plastids Present Absent Plasmodesmata Present Absent Nucleoid Absent Present Plasmid DNA and Capsule Absent Present CELL WALL Outer covering of plant and bacterial cells, enabling additional The cell wall in protection. plants are primarily made from cellulose that covers plant structure. While in bacteria, it is composed of peptidoglycan.  It contains the green pigment that traps CHLOROPLAST light from the sun and converts it into chemical energy in the form of food. Double-layered plastids found mainly in plants serving as the “site of photosynthesis” CENTRAL VACUOLE Storage tank of the cell Membrane-bound organelle that stores food, enzymes, and other materials needed by the cell. Usually large in plants Small but numerous in animals PLASMODESMATA Plasmodesmata are small tubes that connect plant cells to each other, providing living bridges between cells. PLASMODESMATA  NUCLEOID The nucleoid stores the bacterial chromosome, regulates gene expression, facilitates DNA replication, and contains genes essential for various cellular functions. PLASMID DNA Plasmid DNA in bacterial cells are circular in shape, providing genetic advantages, enables horizontal gene transfer, plays a crucial role in biotechnology, and can carry virulence factors.  CAPSULE It provides a physical barrier that helps protect bacteria from being recognized and phagocytosed by immune cells such as macrophages and neutrophils. It enhances the ability of bacteria to adhere to various surfaces, including host tissues, medical devices, and other bacteria.  ACTIVITY 1 A. List down the differences between plant and animal cells. B. Determine the function of the following cells in plants: Meristematic cells (apical, lateral, intercalary) Dermal cell (epidermis, stomata and cuticle) Vascular cell (xylem and phloem) Ground cell (parenchyma, collenchyma, sclerenchyma.  ACTIVITY 1 C. Determine the function of the following cells in animals. Epithelial cells (simple and stratified epithelium) Simple squamous, simple columnar, simple cuboidal, and pseudo-stratified epithelium Stratified squamous, stratified columnar, stratified cuboidal and transitional epithelium Connective cells (dense and loose connective cells/tissue) Muscle cells (smooth, skeletal, and cardiac muscle cells) Nerve cells (neurons and glial cells) 1. Distinguish prokaryotic and eukaryotic cells according to their distinguishing features. 2. Classify different cell types of plant & animal tissues and specify the functions of each. 1. Compare prokaryotic to eukaryotic cell 2. Distinguish plants to animal cells and determine their function 3. Recognize the importance of the cell in living organisms  PROKARYOTIC CELL Prokaryotic cell is the simplest type of cell among all forms of life on Earth. It is structurally and functionally distinct from eukaryotic cell. 1. It has NO true nucleus. Its genetic material is found in the nucleoid. 2. It has NO membrane bound organelle such as mitochondria and chloroplast that are common in eukaryotic cells. 3. It is way smaller in size and surface area compared to eukaryotic cells. 4. The cell wall of prokaryotes are made of peptidoglycan component. 5. Prokaryotic cell have a special type of DNA called Plasmid DNA, a circular DNA that is essential in biotechnology. 6. Prokaryotic cell reproduce through asexual means. 7. Commonly found in bacteria and archaea.  EUKARYOTIC CELL Eukaryotic cells, like in plants and animals, are much complex compared to prokaryotic cell. 1. It has a true nucleus. Its genetic material is arranged as chromosomes. 2. It has membrane bound organelle such as Golgi apparatus, lysosomes, mitochondria and chloroplast. 3. It is way larger in size and surface area compared to prokaryotic cells. 4. The plant cell wall is made of cellulose and chitin for fungi. 5. Eukaryotic cell have complex cytoskeleton for structural support. 6. Eukaryotic cell reproduce through asexual and sexual means. 7. Commonly found in protist, fungi, plants, and animals.  Characteristics Prokaryotic Eukaryotic Presence of nucleus No true nucleus Nucleus is present Arrangement of genetic Single structure (Nucleoid) Chromosomes material Membrane-bound No membrane-bound Contain membrane-bound organelle organelle organelle Size Very small Varies from small to large Cell wall component Peptidoglycan Cellulose and Chitin Mode of reproduction Asexual Sexual and Asexual Example Archaea and bacteria Protist, fungi, plant, and animal  When cells performing a particular function are group together, they can form a tissue that can now perform several functions including protection, growth, and development, simultaneously. In plant structure, cells-forming tissue are classified as: 1. Meristematic tissue Apical meristem Lateral meristem Intercalary meristem 2. Permanent tissue Dermal cells such as epidermis, cuticle, mesophyll and stomata Vascular cells such as xylem and phloem Ground cells such as parenchyma, collenchyma, sclerenchyma MERISTEMATIC TISSUE These are types of cells in plants responsible for growth and elongation. It produces new cells, through mitosis, leading to growth in length and girth (diameter). There are two types of meristematic cells in plants: Apical meristem Lateral meristem  Apical meristem is located both in shoot and root tips of a dicot plant; and in root tips only among monocot plants. This type of meristematic cell is responsible for the primary growth in plants and causes it to elongate (increase in length).  Lateral meristem causes the stem and roots of a dicot plants to grow larger in diameter. This type of growth in dicot plants are called secondary where different layers in stem and roots can be observe.  Intercalary meristem is a special type of meristematic cells found among monocot plants. It is located where the leaf bases connect to the stem of the plant and promotes the lengthening of the stem and increase the height Intercalary meristem of the plant. PERMANENT TISSUE Permanent cells are produced from meristematic cells that quickly differentiates and take on specific function in plant structure. However, unlike meristematic cells, permanent cells are fully grown and no longer actively dividing. DERMAL CELLS Dermal tissue and its specific types of cells covers the plant and can be found on the outer layer of roots, stems and leaves. Dermal tissue covers and protects the plant and functions in transpiration, gas exchange and defense in plant structure. Dermal tissue in plant leave DERMAL CELLS Dermal tissue in plant leave  DERMAL CELLS Cuticle is a waxy substance that covers the leaf and prevents water loss. Epidermis covers all the parts of a plant; shoots, stems, leaves, and roots Stomata are openings in plant Mesophyll represents the leaves that allow a site of photosynthesis in a them to take up plant where light energy carbon dioxide and from the sun is converted release oxygen and into chemical energy and water vapor. stored as foods. Dermal tissue in plant leave VASCULAR CELLS Vascular tissue and its specific cells are the plumbing system of the plant. It allows water, minerals, and dissolved sugars from photosynthesis to pass through roots, stems, leaves, and other parts of the plant. It is primary composed of two types of conducting tissue: xylem and phloem. VASCULAR CELLS Phloem tissue transports organic compounds such as sugars from the site of photosynthesis to rest of the plant. It moves back and forth within the sieve tube element, passing through a small opening called the sieve plate. VASCULAR CELLS Xylem tissue transports water and minerals from the roots to different parts of the plant. The conducting cells of the xylem are called tracheary elements. In xylem tissue, water moves in a one way path only. It moves from roots up to higher structures of plants. GROUND CELLS Plant cells that are not included in dermal or vascular tissues are part of the supportive cells called as the ground cells. 3 types of ground cells Parenchyma Collenchyma Sclerenchyma GROUND CELLS Parenchyma are the most abundant and versatile cell type in plants. The basic functions of parenchyma are photosynthesis and storage. GROUND CELLS Collenchyma is living supportive tissue that has elongated cells and an unevenly thickened primary cell wall. Its main function is the mechanical support of young stems and leaves via turgor.  GROUND CELLS Sclerenchyma is a dead supportive tissue that consists of long sclerenchyma fibers. Its main function is a support of older plant organs, and also hardening different parts of plants. Reference 1: https://herba.msu.ru/shipunov/school/biol_154/textbook/intro_botany.pdf Reference 2: https://organismalbio.biosci.gatech.edu/growth-and-reproduction/plant-development-i-tissue-differentiation-and-function/  Just like plants, animals are made up of tissue. And within those tissue, a group of cells can perform a specific function such as protection, contraction, communication, etc. In animal structure, the four major cells-forming tissue are as follows: 1. Epithelial tissue – covers and line organs 2. Connective tissue – support, adhesion, and insulation 3. Muscle tissue – contraction and locomotion 4. Nervous tissue – rapid communication  Animal Tissue EPITHELIAL CONNECTIVE MUSCULAR NERVOUS TISSUE TISSUE TISSUE TISSUE EPITHELIAL CONNECTIVE MUSCULAR NERVE CELLS CELLS CELLS CELLS  EPITHELIAL CELLS are the type of cells EPITHELIAL TISSUE specialized in giving protection to the body, absorption of nutrients, and secretion of chemicals. There are two classifications of Epithelia based on the number of cells – the simple and stratified epithelium. EPITHELIAL CELLS EPITHELIAL TISSUE Simple epithelium These are protective tissue consist of one layer of cells that are in contact with basement membrane. According to shape and location of the nucleus, there are four types of simple epithelium such as: Simple squamous Simple cuboidal Simple columnar Pseudo-stratified  Simple Epithelium Simple squamous epithelium Simple squamous are flat with smooth edges, forming a tile-like shape. It functions for filtration of substances by rapid diffusion. It is found in the air sacs of the lungs (alveoli) where oxygen and carbon dioxide are exchanged.  Simple Epithelium Simple cuboidal epithelium Simple cuboidal are square in shape and are commonly found in glands. It functions for secretion or absorption of materials. It lines the kidney tubules and follicles of the thyroid gland.  Simple Epithelium Simple columnar epithelium Simple columnar is made- up of single layer of tall cells that fit closely to one another. It lines the entire digestive tract from the stomach to the anus.  Simple Epithelium Pseudo-stratified epithelium It is a type of simple epithelium in which not all cells have the same height and exposed to the surface. Some cells are shorter than the other and their nuclei appear at different heights. Found in trachea and functions for absorption and secretion. EPITHELIAL TISSUE Stratified epithelium These are protective tissue consist of two or more layers of cells. Similar to simple epithelium, stratified epithelium can be classified according to shape such as: Stratified squamous Stratified cuboidal Stratified columnar Transitional  Stratified Epithelium Stratified Squamous Multi-layered squamous cells located on areas that receive good deal of abuse or friction, such as skin, mouth, and esophagus. It serves to protect deeper tissues of the body  Stratified Epithelium Stratified Cuboidal These are two-layered cells Stratified Cuboidal cells that are cube in shape whose function is for absorption and secretion of waste. It is located on the duct of sweat glands and ovarian Basal membrane follicles.  Stratified Epithelium Stratified Columnar The apical layer of stratified Stratified Columnar cells columnar are columnar epithelial cell. But the basal cells vary in shape. It also function for the secretion of waste and can Basal be found in the duct of large membrane glands.  Stratified Epithelium Transitional Epithelium These are highly modified stratified epithelium that forms the lining of urinary bladder, ureter, and urethra. It can stretch and change shape allowing the accumulation of urine in greater volume.  CONNECTIVE EPITHELIAL TISSUE TISSUE, as its name CONNECTIVE TISSUE suggests, connects body parts. It is found everywhere in the body. It perform many functions, but they are primarily involved in protecting, supporting, and binding together other body tissues. EPITHELIAL MUSCULAR CONNECTIVE CELLS CELLS CELLS  CONNECTIVE EPITHELIAL TISSUE TISSUE can be classified CONNECTIVE TISSUE as: Bone Cartilage Blood Dense connective tissue Loose connective tissue Areolar EPITHELIAL MUSCULAR CONNECTIVE Adipose CELLS CELLS CELLS Reticular  Connective tissue: Bone Bones are rock-hard structure that has an exceptional ability to support and protect body organs. It is made-up of osteocyte cells, sitting in cavities called lacunae Bones contain calcium and collagen fiber that makes them a sturdy structure of the body.  Connective tissue: Cartilage Cartilage is less hard and more flexible than bone. Its major cell type is chondrocytes (cartilage cells). It forms the trachea, or windpipe, attaches the ribs to the breastbone, and covers bone ends at joints.  Connective tissue: Blood Blood is the transport vehicle for the cardiovascular system, carrying nutrients, wastes, respiratory gases, white blood cells, and many other substances throughout the body. It is composed of three types of cell: Red blood, White blood, and Platelets.  Connective tissue: Dense Dense Connective tissue supports, protects, and holds bones, muscles, and other tissues and organs in place. It is composed of tightly packed collagen fiber bundles with tightly squeezed fibroblast It forms strong, ropelike structures such as tendons and ligaments.  Connective tissue: Loose Loose Connective tissue, relatively speaking, are softer and have more cells and fewer fibers than any other connective tissue type except blood. There are three main types of loose connective tissue: Areolar Adipose Reticular  Connective tissue: Loose Areolar Connective tissue, is a soft, pliable tissue that cushions and protect the body organs it wraps. It serves as universal packaging tissue, holding internal organs together in their position.  Connective tissue: Loose Adipose Connective tissue, commonly called fat, forms the subcutaneous tissue beneath the skin, where it insulates the body and protects it from bumps and extremes of both heat and cold.  Connective tissue: Loose Reticular Connective tissue, forms the stroma or internal framework of an organ. It supports lymphocytes in lymph nodes, spleen, and bone marrow. MUSCULAR MUSCULAR TISSUE, are highly TISSUE specialized to contract, or shorten, which generates the force required to produce movement. There are three types of muscle tissue: Skeletal – muscles attached to the bones Cardiac – muscles of the heart MUSCULAR CELLS Smooth – muscles lining the organs MUSCULAR CELLS  NERVOUS TISSUE, is specialized for NERVOUS communication. The tissue consists of TISSUE two major cell types: neurons and glial cells. Neurons communicate with each other via electrical and chemical signals. They have nucleated cell bodies and two types of elongated cellular NERVE processes: the axons and dendrites. CELLS Anatomy of Neuron (Nerve cell) Cell body: The metabolic center of the neuron Dendrites: Receive signals towards the cell body. Axon: Generate nerve impulses and conduct them away from the cell body.