Survey
* Your assessment is very important for improving the work of artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the work of artificial intelligence, which forms the content of this project
Tissues of the Body Histology: – the study of tissues. From Cells to Organ Systems • Cells combine to form tissues, and tissues combine to form organs Four Basic Kinds of Tissues • Epithelial Tissue • Connective Tissue • Muscle Tissue • Nervous Tissue Diversity in structure and function… anatomy & physiology! Epithelial Tissue • Epithelial Tissue Locations: – Covers the body – Lines the cavities, tubes, ducts and blood vessels inside the body –Covers the organs inside body cavities Epithelial Tissue • Epithelial Tissue Functions: – Protection from physical & chemical injury – Protection against microbial invasion – Contains receptors which respond to stimuli – Filters, secretes & reabsorbs materials – Secretes serous fluids to lubricate structures Epithelium • Two FUNCTIONAL types: – membranous epithelia • form the coverings or linings of organs – glandular epithelia • form exocrine and endocrine glands Epithelium STRUCTURAL types: Simple SHAPE Squamous Cuboidal Stratified LAYERS Columnar Epithelium-Human Stomach Glandular Epithelia • Figure 4.4 Connective Tissue • Connective Tissue: – Most abundant & widely distributed tissue • Connective Tissue Functions: – Connects, binds and supports structures, • Tendons, ligaments, etc. – Protects & cushions organs and tissues, – Insulates (fat) and – Transports substances (blood). Connective Tissue • Binds the cells and organs of the body together – All connective tissues consist of two basic components: cells and extracellular fibers • Two types of connective tissue are: – Connective tissue proper – Specialized connective tissue Section 4-1 Connective Tissue Connective Tissue • An important structural component of organs – Consists of two types: • Loose connective tissue • Dense connective tissue Specialized Connective Tissues • Perform specific functions essential to homeostasis • The body contains three types of specialized connective tissue: BLOOD Contains blood cells, platelets, plasma Consists of bone cells (osteocytes) BONE and a calcified cartilage matrix Two types: • spongy • compact Consists of specialized cells CARTILAGE embedded in a matrix of extracellular fibers and other extracellular material Muscle Tissue • Muscle Tissue: – Associated with the muscle of the skeleton, the heart and in the walls of the hollow organs of the body. • Muscle Tissue Functions: – Movement – – – – – – - Locomotion Maintains posture Produces heat Facial expressions Pumps blood Peristalsis = movement of substances through body (i.e. swallowing, intestinal, ovulation) Muscle Tissue • Consists of specialized cells that contract when stimulated • The body has three types of muscle tissue: • Skeletal (voluntary) • Cardiac (involuntary) • Smooth muscle (involuntary) Nervous Tissue • Nervous Tissue: – Main component of the nervous system, ie., brain, spinal cord & nerves. • Nervous Tissue Functions: – Regulates & controls body functions – Generates & transmits nerve impulses – Supports, insulates and protects impulse generating neurons. Nervous Tissue • Contains specialized cells that conduct impulses • Conducting cells, called neurons, transmit impulses from one region of the body to another. • Nonconducting cells, neuroglia, are a type of nervous system connective tissue. Nerve Tissue TISSUE LAB You will view 6 of the following: EPITHELIAL (2) – Stratified squamous – Simple columnar – Pseudostratified columnar CONNECTIVE – – – – (2) Adipose Blood Bone Hyaline Cartilage MUSCLE (1) – Smooth – Skeletal – Cardiac NERVOUS (1) – Motor neuron Tissue Repair (Wound Healing) • Regeneration – Replacement of destroyed tissue by the same kind of cells – No clotting; no scar • Fibrosis – Repair by dense (fibrous) connective tissue – Scar tissue results • Determination of method – Type of tissue damaged – Severity of the injury Events in Tissue Repair 1. Capillaries become very permeable – Introduce clotting proteins – A clot walls off the injured area 2. Formation of granulation tissue – Growth of new capillaries – Rebuild collagen fibers 3. Regeneration of surface epithelium – Scab detaches Tissues that regenerate very well – Epithelial tissue (skin and mucous membranes) – Fibrous connective tissues (areolar, dense) – Bone – Blood forming • Tissues that cannot regenerate at all –Cardiac muscle –Nervous tissue within the brain and spinal cord • Moderate regeneration - Smooth - Dense regular • Weak regeneration • Skeletal muscle • Cartilage Scar Tissue Build up of scar tissue obstructs or limits movements of smooth muscle. Example: 1. Stomach – churning and twisting of foodstuffs 2. Blood vessels – constricting to move blood through