Animal Tissues PDF

1  Introduction  Any distinct type of material animal cells are made of, which consists specialized cells and cellular products, which show inflammation reaction to any infection or injury are known as tissues. In animal organs are made up of four basic ty...

1  Introduction  Any distinct type of material animal cells are made of, which consists specialized cells and cellular products, which show inflammation reaction to any infection or injury are known as tissues. In animal organs are made up of four basic types of tissues epithelial tissue, connective tissue, muscle tissue and nerve tissue. These tissues have distinctive features and specific functions which combine to form functioning organs.  A tissue is composed of cells that function together in a specialized activity. 2  There are four types of tissues found in an animal. 1. Epithelial tissue 2. Connective tissue 3. Muscle tissue 4. Nervous tissue 3 1. Epithelial tissue Forming tight covering and protecting layers below 2. Connective tissue Holding other tissues together and are surrounded by lots of nonliving material. 4 3. Muscle tissue Shortening and lengthening to move other tissues. Nucleus of 4. Nervous tissue Dendrites schwann cell Layer of myelin Allowing rapid flow of ions Nucleus in and out to conduct Cell body Axon signals Axon Myelin sheath Node of ranvier 5 Terminal knob  1.Epithelial tissues  Two types of epithelial tissues 1. Covering and lining epithelium ( outer layer of the skin and some organs) 2. Glandular epithelium ( constitute the secreting portion of glands) 6  Epithelial tissues  There are three types of cells in epithelial tissues 1. Squamous – thin flat cells Form the lining of cavities such as the mouth, blood vessels, heart and lungs and make up the outer layers of the skin 7 2. Cuboidal – cells are roughly square Each cell has a spherical nucleus in the center Found in glands and in the lining of the kidney tubules 3.Columnar - elongated cells. Nuclei are elongated and are usually located near the base of the cells Columnar epithelium forms the lining of the stomach and intestines Some columnar cells are specialized for sensory reception such as in the nose, ears and the taste buds of the tongue 8  Epithelial tissues  Three types of cell layers exist in epithelium tissues Epithelium tissue Simple Stratified Pseudo epithelium epithelium epithelium 9  CELL LAYERS  Simple epithelium  Stratified epithelium made up of only one has more than a cell layer single layer of cells  Pseudostratified epithelium made up of cells that reach the basement m embrane and appear to be stratified because their nuclei are at different levels. 10  Glandular epithelium  Glands are made up of single or a mass of epithelial cells.  Two types of glands 1. Exocrine - Secrete their products in to ducts Eg. Salivary glands and mammary glands 2. Endocrine - Secrete their products into blood stream Eg. Pancreas 11 Functions of epithelial tissues 1. Provides physical protection 2. Controls permeability 3. Detects sensations (sight, smell , taste, equilibrium) 4. Secretion of hormones into the blood vascular system, and/or the secretion of sweat, mucus, enzymes, and other products that are delivered by ducts 12 2. Connective tissue  Most abundant and most widely distributed tissue in the body.  These tissues provide support for organs and the body as a whole, protect and insulate internal organs and compartmentalize structures such as skeletal muscles, nerves. 13  Connective tissue  Connective tissue is made up of cells, ground substances and fibers. Ground substances together with fibers make matrix. 14  Connective tissue  There are 3 main types of connective tissue Loose Connective Tissue Fibrous Connective Tissue Specialized Connective Tissues Adipose Tissue (Fat) Cartilage Bone Blood 15 Loose Connective Tissue (LCT)  Fibroblasts are separated by a collagen fiber-containing matrix  Collagen provides elasticity and flexibility  Occurs beneath epithelium in skin and many internal organs  Forms a protective layer over muscle, nerves and blood vessels 16 Fibrous Connective Tissue (FCT)  Consists of many collagen fibers closely packed together  Occurs in tendons, connecting muscle to bone  Makeup ligaments, connecting bone-to- bone at a joint 17 Adipose  Another name for fat  Insulates the body and provides padding  Cellssometimes referred to as “ghost cells” 18 Cartilage  Soft  Structural proteins deposited in the matrix between cells  Forms embryonic skeletons  Occurs in mature human adults in ears, joints and tip of nose 19 Blood tissue – Blood transports nutrients and oxygen to cells and removes carbon dioxide and other wastes Blood cells are separated by plasma Types – red blood cells, white blood cells, platelets 20 Bone tissue Cells are called osteocytes Hard Calcium salts deposited in matrix Proteins provide elasticity while minerals provide strength Dense bone has osteocytes located in lacunae (Haversian canals) Spongy bone occurs at the end of bones and absorb stress (two types; compact and spongy) compact – with osteons spongy - no osteons 21 Muscle Tissue  Facilitatesmovement by contraction of individual muscle cells referred to as muscle fibers  Found only in members of the animal kingdom  Three types:  Skeletal (Striated)  Smooth  Cardiac 22  These cells have main properties 1. Excitability ( ability to respond to stimuli) 2. Contractibility (ability to contract) 3. Extensibility (ability to be stretched without tearing) 4. Elasticity (ability to return to its normal shape) 23  Muscular Tissue  Muscle tissue is classified into three types (Cardiac, Skeletal and Smooth) 24 Skeletal Muscle  Function in conjunction with the skeletal system in voluntary muscle movement  Striated with alternating bands at right angles to the long axis of the cell  The bands are areas of actin and myosin deposition  Striated, voluntary, and multinucleated 25 Smooth Muscle  Lack banding  Spindle shaped cells that form masses  Function in involuntary movements and/or autonomic responses like breathing, secretion, etc.  Make up structures in the digestive system, reproductive tract and blood vessels  non-striated, involuntary, and single nucleus 26 Cardiac Muscle  Striated  Limited to the heart  Cells are forked, with nucleus near the center  Cells are connected together by disks  Intercalated disks  striated, involuntary, and single nucleus 27 Nervous Tissue  Importantin the integration of stimulus and control of the response to that stimulus  Made of nerve cells called neurons and glial cells (helper cells)  Neurons transmit nerve messages  Glial cells are in direct contact with neurons and often surround them 28  The neuron is the functional unit of the nervous system  Variable in size and shape  Humans have about 100,000,000,000 (100 billion) neurons in their brain! Wow! 29  Nervous Tissue  Cells of nervous tissue have three principal parts 1. Dendrites Nucleus of schwann cell 2. Cell body Dendrites Layer of myelin 3. Axon Nucleus Axon Cell body Axon Myelin sheath Node of ranvier 30 Terminal knob  Nervous Tissue  Neuroglial cells that do not transmit impulses but instead support the activities of the neurons.  Schwann cells, a type in the peripheral nervous system only in mammals. 31  Tendon Squamous Areolar Striated Ligament Cuboidal Smooth Adipose Columnar Cardiac Bone Cilliated Skeletal Cartilage Glandular Fluid Blood Lymph 32