PLANT TISSUESCeleste Roderno-

Desingaño

Two Major Categories of Plant Tissues1. Meristematic Tissue

A. Apical MeristemsB. Lateral Meristems

2. Permanent TissueA. 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 TISSUEA. Dermal (Surface Tissue)

Forms the protective outer covering of the plant body

A.1. Epidermis Produce cutin to

protect plants against loss of water

Produce root hairs for absorption of water and minerals

A.2. Periderm 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.

B.1. Parenchyma Parenchyma on

leaves function for photosynthesis

Mechanical strength by maintaining turgidity and also store waste products.

B.2. Collenchyma Support of stems

and adapt themselves to the rapid elongation of leaves.

B.3. Sclerenchyma Provides elasticity,

flexibility, and rigidity to the plant body forming support.

PERMANENT TISSUE

C. Vascular TissueC.1. Xylem

Primarily functions for the transport of water and dissolved substances upward in the plant body.

C.2. Phloem Primary functions

in the transport of organic materials such as carbohydrates and amino acids.

ANIMAL TISSUES

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 TISSUEFunctions:

Serves as binding substance Provides framework Has essential role in transport, protection and repair.

Classification of Connective Tissue

A. Connective Tissue Proper

B. Cartilage

C. Bone

D. 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 Proper2. 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

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

1. Hyaline cartilage –nose, larynx, trachea, bronchi, ends of ribs and surfaces of bones.

2. Elastic cartilage – yellow color, greater flexibility and elasticity and found in the external ear, Eustachian tube and epiglottis

3. Fibro cartilage – resembles a tendon but not covered by perichondrium

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

1. Long Bone Composed of middle

portion, the diaphysis or shaft, within which is a cavity, and the epiphysis or ends of the bone.

2. Flat Bone Lacks a bone marrow

cavity.

3. 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.

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. Blood (Vascular Tissue)

D. VASCULAR TISSUE2. 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 TISSUE3. 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

contractionb. 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 Tissuea. Nervous Tissue Proper Has specialized conducting

cell called neuron, linked together to form pathways.

b. Interstitial Tissue (Neuroglia) Supports the 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.

2. Dendrites

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

NEURON

Types of Neurons1. 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

3. Interneurons/Association

Convey nerve impulses between various parts of the CNS