BIOLOGICAL SCIENCE~plant and animal tissuesPresentation Transcript
PLANT TISSUES Celeste Roderno-Desingaño
Two Major Categories of Plant Tissues 1. Meristematic Tissue A. Apical Meristems B. Lateral Meristems 2. Permanent Tissue A. Dermal (Surface Tissue) B. Fundamental Tissue (Ground Tissue) C. Vascular Tissue
MERISTEMATIC TISSUE Composed of immature cells and are regions of active cell division. Tend to be small, have thin walls and rich in cytoplasm. Found in the growing tips of the roots and stem. A. Apical Meristems
Responsible for increase in length of the plant body.
Found on root tips and apical buds
B. Lateral Meristems
Responsible for increase in girth or diameter
Ex: Cambium present in woody plants and produce the cork
PERMANENT TISSUE A. Dermal (Surface Tissue)
Forms the protective outer covering of the plant body
Produce cutin to protect plants against loss of water
Produce root hairs for absorption of water and minerals
Replaces the epidermis
Constitutes the corky outer bark of old trees.
PERMANENT TISSUE B. Fundamental (Ground Tissue)
Used in the production and storage of food and in the support of plant.
Parenchyma on leaves function for photosynthesis
Mechanical strength by maintaining turgidity and also store waste products.
Support of stems and adapt themselves to the rapid elongation of leaves.
Provides elasticity, flexibility, and rigidity to the plant body forming support.
PERMANENT TISSUE C. Vascular Tissue C.1. Xylem
Primarily functions for the transport of water and dissolved substances upward in the plant body.
Primary functions in the transport of organic materials such as carbohydrates and amino acids.
Animal Tissues Developed from the primary germ layers of the embryo: Ectoderm Mesoderm Endoderm There are 4 types of tissues: Epithelial tissue Connective tissue Muscular tissue Nervous tissue
I. EPITHELIAL TISSUE Made up of continuous sheets of densely packed cells, with little space or intercellular material between them. A basement membrane is usually present. Functions: 1. Forms the covering or lining of all free body surfaces, both internal and external to protect cells from mechanical injury and water loss. 2. Some has special functions of absorption, secretion, excretion, sensation and respiration.
Classification of Epithelial Tissuebased on Shape and Arrangement of Cells
Simple squamous –found in the lens of the eye and inner ear Stratified squamous – forms the external layer of the skin and lines the mouth and pharynx. Cuboidal – mostly found lining small ducts and tubules of the kidney and the glands Simple columnar – found in the trachea, bronchi, digestive tract and secrete fluids and absorb digestive food.
II. CONNECTIVE TISSUE Functions: Serves as binding substance Provides framework Has essential role in transport, protection and repair. Classification of Connective Tissue Connective Tissue Proper Cartilage Bone Blood (Vascular Tissue)
A. Connective Tissue Proper Very variable but intercellular matrix always contains numerous fibers. 2 Types of Connective Tissue Proper 1. Loose Connective Tissue Made up of highly elastic fibers with few scattered thin collagen fibers. This tissue fills the space between organs and serves as packing materials surrounding the elements of other tissues This binds muscle cells together and binds skin to underlying tissues Ex. Adipose tissue, areolar tissue
A. Connective Tissue Proper 2. Dense Connective Tissue Made up of thick collagen fibers and dark, compressed cells between the fiber bundles. Functions: (1) for flexibility and support, (2) shock absorption and (3) reduction of friction. Ex. Tendon, ligament, urinary tract and collagen
Elastic cartilage – yellow color, greater flexibility and elasticity and found in the external ear, Eustachian tube and epiglottis Fibro cartilage – resembles a tendon but not covered by perichondrium B. Cartilage Made up of cartilage cells known as chondrocytes found in cavities called lacunae Scattered irregularly in matrix that appears transparent and homogenous but composed of dense collagen fibers and elastic fibers embedded in a rubbery ground substance. Produced by chondroblast in the process called chondrification. Provides smooth surfaces and maintain the shape of the area. Types of Cartilage Hyaline cartilage –nose, larynx, trachea, bronchi, ends of ribs and surfaces of bones.
C. Bone (Osseous tissue) Has hard, relatively rigid matrix which contains numerous collagen fibers and a surprising amount of water, impregnated with mineral salts such as calcium carbonate and calcium phosphate. Bone is a living tissue with cells called osteocyte and masked collagenous fibers embedded in a matrix containing ostein. Covered with fibrous membrane –periosteum Lines the bone marrow cavity- endosteum Functions: (1) support; (2) protection; (3) assisting for movement and (4) storage of minerals
Classification of Bone According to Shape Long Bone Composed of middle portion, the diaphysis or shaft, within which is a cavity, and the epiphysis or ends of the bone. Flat Bone Lacks a bone marrow cavity. Irregular Bone Neither long nor flat and also lacks marrow cavity Example: Humerus and Femur bone Example: Cranial Bone and Scapula bone Example: Metacarpal and Metatarsal bone
Osteon or Haversian System-basic unit of bone Lamellae Series of concentric rings or circles of matrix around a large central Haversian canal Lacunae Small spaces in between the lamellae which contain the osteocytes Osteocyte Bone cell Canaliculi Minute channels that linked lacunae together which provide routes by which nutrients can reach the osteocytes and the removed waste materials Haversian Canals Central tubes which contain blood vessels and nerves.
C. Bone Contains bone marrow (Yellow and red marrow) Yellow marrow consists of fat cells, blood vessels, and a minimal framework of reticular cells and fibres. Red marrow consists of numerous blood cells of all kinds, as well as the substances from which these cells are formed The functions of red marrow are (1) the formation of red blood cells (erythrocytes), blood platelets, granulocytes, and to a lesser extent monocytes and lymphocytes, and (2) the destruction of old (c.120 days), worn-out erythrocytes.
D. Blood (Vascular Tissue) Consists of cells, matrix and fibers 3 Components of Blood 1. Erythrocyte (RBC) small, concave, disc-shaped cells that lack nuclei during maturation in mammals Formed in the bone marrow They arise from normally nucleated, rapidly dividing connective tissue cells of the bone marrow Contains hemoglobin
D. VASCULAR TISSUE 2. Leukocyte (WBC) Bigger than erythrocyte and have large, often irregularly shaped nuclei Defenses against disease and infection Act as phagocytes, engulfing and destroying bacteria and remnants of damaged tissue cells Produce powerful enzyme Lymphocytes –specialized cells that play a central role in immune reactions by producing antibodies.
D. VASCULAR TISSUE 3. Platelets (Thrombocyte) Small, non-nucleated, colorless, round or oval biconcave corpuscle produced by a giant cell called megakaryocyte found in the bone marrow. Functions for blood clotting 4. Plasma Liquid component of blood. 5. Hemoglobin The protein constituent of blood
III. MUSCLE TISSUE Function: responsible for movement in higher animals, heat production and maintenance of posture. Types of Muscle Tissue a. Striated or Voluntary Muscle (Skeletal Muscle) Has cross-striations (A-I bands) and can be controlled at will Consists of myofibrils which contains actomyosin. Sarcomere-the functional/structural unit of muscle contraction b. Smooth or Involuntary Muscle (Visceral Muscle) Spindle-shaped cells which are thickened at the middle but tapered towards ends. Without striation and responsible for involuntary movements of internal organs c. Cardiac Muscle Striated and branched muscle fibers Found exclusively in the heart (myocardium) and is involuntary in movement.
IV. NERVOUS TISSUE Highly specialized for the conduction of nerve impulses. Division of Nervous Tissue a. Nervous Tissue Proper Has specialized conducting cell called neuron, linked together to form pathways. b. Interstitial Tissue (Neuroglia) Supports the neuron
NEURON 1. Cell body (soma/cyton)
Enclosed by a membrane, with nucleus, cytoplasm and cellular organelles.
Produces proteins and energy required for the function of the neuron.
Numerous extensions that is short and branched
receive signals from sensory receptors
Connect with other neurons to collect stimuli and pass these on to the cell body
NEURON 3. Axon
Projections from the cell body that is long and thin
conducts nerve impulses
Any long axon is also called a nerve fiber
Covered by myelin sheath
4. Terminal Branches/ Synaptic Terminals
Attached to receptors of the body
Types of Neurons 1. Motor Neurons/Efferent
Accept nerve impulses from the CNS
Transmit them to muscles or glands
2. Sensory Neurons/Afferent
Accept impulses from sensory receptors
Transmit them to the CNS
Convey nerve impulses between various parts of the CNS