Presentation on theme: "Tissues and Integumentary (Skin) System Nestor T. Hilvano, M.D., M.P.H. (Images Copyright Discover Biology, 5 th ed., Singh-Cundy and Cain, Textbook, 2012.)"— Presentation transcript:
Tissues and Integumentary (Skin) System Nestor T. Hilvano, M.D., M.P.H. (Images Copyright Discover Biology, 5 th ed., Singh-Cundy and Cain, Textbook, 2012.)
Learning Objectives 1.Describe the 4 main types of tissues, noting their structures, locations, functions and examples. 2.Describe the functions of the different organ systems. 3.Differentiate the types of epithelial tissues as to structure, function, and give an example for each. 4.Compare and contrast the 3 types of muscles. 5.Describe the nervous tissues. 6.Discuss the two main layers of the skin, including it’s functions and appendages. 7.Discuss homeostasis and distinguish between negative and positive feedback.
Overview of Structure and Function of Organism ___ What is the study of structures or parts of the body? ___ of function? ___ study of tissues? a) histology b) anatomy c) microbiology d) anatomy ___ is a group of similar cells with a common function. ___ is made up of several (different types) tissues. ___ is composed of many organs that work together to perform life functions. a) organ system b) organ c) tissues d) organism
Systems (Organ-System) –The digestive and respiratory systems Gather food and oxygen –The circulatory system, aided by the lymphatic system Transports the food and oxygen –The immune system Protects the body from infection and cancer –The excretory system Disposes of certain wastes –The endocrine and nervous systems Control body functions –The integumentary system Covers and protects the body –The skeletal and muscular systems Support and move the body –The reproductive system Perpetuates the species
4 Main (Fundamental) Types of Tissues 1.epithelial tissue 2.connective tissue 3.muscular tissue 4.nervous tissue
Epithelial Tissue Covers the body and lines its organs and body cavities Common features/characteristics of epithelium: a) closely packed cells b) lie on basement membrane c) avascular d) can be derived from 3 germ layers (ectoderm, mesoderm, endoderm) Functions = protection, secretion, absorption, filtration, sensory receptor, excretion, lubrication.
Pseudostratified columnar Types of Epithelial Tissues: __ 1 layer of cells. __ 2 or more layers of cells. __ false layers of cells (false stratification). a.Stratified epithelium b.Pseudostratified epithelium c.Simple epithelium d.Transitional epithelium
Simple Epithelium Simple squamous - function: exchange of materials, diffusion, or filtration - example: endothelium of blood vessels, alveoli of lungs Simple cuboidal - function: absorption or secretion - example: kidneys tubules (w/brush border= microvilli), ducts of glands, thyroid follicles Simple columnar - function: absorption or secretion - example: digestive (GIT) tracts (w/ goblet cells, striated border= microvilli) Exercises: What is the fingerlike projections of cell membrane that increases surface area for absorption? a. cilia b. microvilli c. flagella d. gap junction
Stratified Squamous Stratified squamous - several layers of cells, squamous (flat) superficial cells - function: protective barriers Stratified squamous non- keratinized- outermost squamous cells are alive, nucleated squamous cells; found in oral cavity, esophagus, vagina Stratifies squamous keratinized (cornified)- outermost cells are dead, non-nucleated cells, with keratins; found in epidermis of skin
Pseudostratified Columnar Pseudostratified Columnar- false layers of cells, with cilia on surface and goblet cells; protection, secretion, and absorption Found in respiratory passages like trachea, bronchi, bronchioles Exercises: __ What are the hair-like structures that move in a sweeping motion to remove (filter) inhaled particles along the respiratory tract? __ What is responsible for mucous secretion to lubricate and help trap dust and foreign particles in the respiratory passages? a. microvilli b. goblet cells c. cilia d. columnar cells
Connective Tissue Common features/characteristics of C.T.: a) Few cells in an extracellular matrix (solid, semi-solid) b) vascular c) matrix contains 3 C.T. fiber types –Collagen fibers provide strength and flexibility (strong fibers) –Elastic fibers stretch and snap back to their original length (recoil) –Reticular fibers join connective tissue to adjacent tissues Fibroblast cells- secrete the C.T. matrix Functions = mainly binds and supports other tissues
Nervous Tissue Communication network – senses stimuli and transmit nerve signals that help control body activities CNS (brain and spinal cord) and PNS (nerves and ganglia) Consists of neurons (nerve cells) and neuroglial (supporting) cells ___ What is the functional and structural unit of nervous system? a. nerve fiber b. neuroglia c. ganglia d. neuron
Integument (Skin) 2 main layers- Epidermis and dermis Epidermis- stratified squamous keratinized; melanocytes protect from UV radiation Dermis- C.T., consists of: a) papillary layer (loose C.T.), and b) reticular (dermis proper) layer (DICT), w/c contain appendages (hair follicles, sweat glands, sebaceous (oil) glands, & arrector pili muscle), blood vessels, and nerves Subcutaneous tissue (hypodermis) - supporting tissue w/c binds the skin to underlying structures (muscles). Figure 26.5
Homeostasis and Feedback Mechanism Homeostasis - Stable internal conditions regardless of external conditions= equilibrium Negative feedback - Body senses a change and activates mechanisms to reverse it (negates the change); important to maintain health (good + feedback). ex: thermoregulation of the body Positive feedback - Self-amplifying change (in the same direction). ex: fever (bad + feedback); increase blood clotting to stop bleeding (good + feedback)
Fig Sweat glands secrete sweat, which evaporates, cooling the body. Thermostat in hypothalamus activates cooling mechanisms. Blood vessels in skin dilate: capillaries fill; heat radiates from skin. Increased body temperature Decreased body temperature Thermostat in hypothalamus activates warming mechanisms. Blood vessels in skin constrict, reducing heat loss. Skeletal muscles contract; shivering generates heat. Body temperature increases; thermostat shuts off warming mechanisms. Homeostasis: Internal temperature of 36–38°C Body temperature decreases; thermostat shuts off cooling mechanisms.
Homework 1.Define terms: anatomy, physiology, histology; tissues; organs; systems; epithelial tissue, connective tissues; muscular tissues; melanocytes, nervous tissues; homeostasis; negative feedback, and positive feedback. 2.Describe characteristics of epithelial tissues as to structural organization. 3.Describe simple squamous, simple cuboidal, simple columnar, stratified squamous, and pseudostratified columnar epithelium as to cell layer/s and function/s and give an example where these are located. 4.Describe the common features of connective tissues, connective tissue fibers, and types (forms) of connective tissues. 5.Describe the 3 types of muscle tissues. 6.Describe nervous tissues. 7.Discuss the 2 main layers of skin. 8.What is the importance of hypodermis. 9.Describe the skin appendages. 10.Discuss the negative feedback mechanism of thermoregulation by an example.