genbio

• According to Britannica (2023), animal, any of a group of multicellular eukaryotic organisms.
• They are thought to have evolved independently from the unicellular eukaryotes.
• Animals differ from members of the two other kingdoms of multicellular eukaryotes, the plants and the fungi, in fundamental variations in morphology and physiology.
• This is largely because animals have developed muscles and hence mobility, a characteristic that has stimulated the further development of tissues and organ systems.
• SKIN CELLS

  Consists of keratinocytes and melanocytes.

  Keratinocytes make up 90% of all skin cells. They produce a protein called keratin. Melanocytes produce melanin which gives color to skin.
• muscle cells

  Myocytes or muscle cells are long tubular cells that help organisms move their limbs and organs.

  Muscle Cells
• Blood Cells

  Blood cells can be either red blood cells or white blood cells. Red blood cells make up 99% of all blood cells and delivers oxygen to different parts of the body. White blood cells find and destroy pathogens and other harmful substances in the body.
• Fat Cells

  Adipocytes or lipocytes are storage cells for fats and lipids which are reserves of energy.
• Nerve Cells

  Neurons or nerve cells are the main cells of the nervous system. They carry messages and deliver signals to different parts of the body using their dendrites and axons.
• Bone cells

  Osteocytes are majority of cells embedded within the substance of fully formed lobe.
• Epithelial

  • Covers body surfaces and lines body cavities, some epithelial cells secrete glands.
• Connective

  • Binds and supports body parts.
• Muscular

  • Long cylindrical fibers arranged in parallel arrays which allows the parts of the body to move.
• Nervous

  • Receives, processes, and transmits information from one part of the body to another.
• Squamous Epithelium

  • Flat and thin cells with no intercellular spaces between cells.

  • Found in the outer layer of the skin, in the lining of cavities, blood vessels, and in the chambers of the heart.

  epithelial tissue
• Columnar Epithelium

  • Cylindrical in shape, it facilitates the movement of nutrients across epithelial barrier.

  • Found in the lining of stomach and intestines.

  Epithelial Tissue
• Glandular Epithelium

  • It forms from a columnar epithelial cell, it secretes substances.

  • Found in the sweat glands of the skin and tear glands of the eye.

  Epithelial Tissue
• Ciliated epithelium

  • A columnar cell with hair-like projections called cilia.

  • Cilia push the mucus forward into the nasal tract to clear it.

  • Found in the lining of the respiratory tract.

  Epithelial Tissue
• Cuboidal epithelium

  • Cube-like in shape, it provides mechanical support to organs.

  • Found in the lining of kidney tubules, salivary glands, and thyroid glands.

  Epithelial Tissue
• Stratified Epithelium

  • Forms layers of epithelial cells, composed of one or different types of epithelial cells.

  • Found in the epidermis of the skin, lining of the mouth cavity, and esophagus.

  Epithelial Tissue
• Blood

  • A fluid connective tissue composed of plasma, red blood cells, white blood cells, and platelets.

  • It flows through blood vessels carrying oxygen, nutrients, hormones, and antibodies to different parts of the body.

  • Found in blood vessels.

  Connective Tissue
• Bone

  • Bone cells are embedded in a matrix composed of calcium and phosphorous compounds.

  • They are hard and porous.

  • They anchor muscle tissues, protect internal organs, and give mechanical support to the entire body.

  Connective Tissue
• Fibrous Connective Tissues

  • Ligaments connect two bones, on the other hand, tendons connect bones to the muscles.

  • They add strength to muscles.

  • Found in ligaments and tendons.

  Connective Tissue
• Cartilage

  • Widely spaced cells suspended in a matrix of protein and sugars.

  • Adds mechanical support and flexibility.

  • Found in nose, ears, trachea, and at the end of long bones for flexibility.

  Connective Tissue
• Areolar Connective Tissue

  • Cells that fill the space inside organs and give them mechanical support.

  • Found between the skin and muscles, around blood vessels and nerves.

  Connective Tissue
• Adipose Connective Tissues

  • Filled with fat globules, they act as an insulator.

  • Found in below the skin, around internal organs.

  Connective Tissue
• Striated Muscle (Skeletal)

  • Cylindrical in shape and contains many nucleus. Each muscle fiber has alternating dark and light-colored bands called striations.

  • Help animals move limbs and lift objects. It is a voluntary muscle.

  • Found in limbs, hands main body trunk, face, and neck.

  Muscular Tissue
• Unstriated Muscle (Smooth)

  • Has the shape of a spindle, and has one nucleus, has no striations.

  • It moves food down the esophagus, stomach, and through the intestines.

  • It is an involuntary muscle.

  • Found in alimentary canal, eye, urinary bladder, and bronchi of the lungs.

  Muscular Tissue
• Cardiac muscle

  • Branched muscle, cylindrical in shape with a single nucleus.

  • Its contraction and relaxation produce heartbeats which force blood to circulate.

  • It is an involuntary muscle. • Found in heart

  Muscular Tissue
• Neuron

  • A nerve cell which is the building block of the nervous system.

  • It specializes in receiving, processing, and transmitting information throughout the body.

  Nervous Tissue
• • Glial Cell (Neuroglia)

  • Surrounds neurons and holds them in place, supplies nutrients and oxygen to neurons, insulates one neuron from another, destroys pathogens and dead neurons.

  Nervous Tissue
• Neurons receive, process, and send out information to other parts of the body.

  • The branchlike structures of dendrites and axons facilitate the conduction of these impulses.

  Some Specialized Cells in the Human Body
• Muscle cells make physical movement of organs and body parts possible.

  • Their banded muscle fibers give the cell strength.

  • They are flexible and elastic which allow the contraction and relaxation of muscles.

  Some Specialized Cells in the Human Body
• Sperm Cells

  • They are specialized for human reproduction.

  • The prominent parts of a sperm cell are the nucleus and tail.

  • The tail allows the sperm cell to be mobile and vigorous in swimming through the vaginal canal.

  • Its prominent head allows it to penetrate the female egg cell.

  Some Specialized Cells

  in the Human Body
• Ovum Cells

  • They are the female reproductive cells.

  • The prominent part of an egg cell is its main body which is significantly larger than sperm cells.

  • An egg cell is covered by corona radiata which are layers of follicle cells that supply vital proteins to the egg cell.

  Some Specialized Cells in the Human Body
• Red Blood Cells

  • Red blood cells, transport oxygen to body tissues and carry carbon dioxide back to the lungs.

  • A red blood cell has a bi-concave shape which gives it a larger surface area for gas exchange.

  • This shape also adds to its flexibility, enabling the blood to pass through narrow capillary vessels.

  Some Specialized Cells in the Human Body
• White Blood Cells

  • WBCs identify and destroy pathogens.

  • They have granules which engulf and digest bacteria.

  • They have a long and narrow shape to allow them to pass through narrow gaps.

  Some Specialized Cells in the Human Body
• Microvilli

  • Microvilli are finger-like projections in the intestinal wall which increase the intestines surface area, and thus increase the intestines’ absorptive capacity.

  Some Specialized Cells in the Human Body
• Ciliated Epithelial Cells

  • Ciliated epithelial cells have hair-like projections that allow the cell to push mucus forward into the nasal tract to clear the passageway of the respiratory tract.

  Some Specialized Cells in the Human Body