Anatomy & Physiology: Cells and Tissues PDF

Anatomy & Physiology Cells and Tissues Prof. Janice M. Erlano, RN The Cell 3 PRINCIPLES Theory All organisms are made of cells is a scientific theory first formulated in the mid- nineteenth century, that All existing cells are organis...

Anatomy & Physiology Cells and Tissues Prof. Janice M. Erlano, RN The Cell 3 PRINCIPLES Theory All organisms are made of cells is a scientific theory first formulated in the mid- nineteenth century, that All existing cells are organisms are made up of produced by other living cells cells, that they are the basic structural/ organizational unit of all The cell is the most basic organisms, and that all cells unit of life come from pre-existing cells. BODY ORGANIZATION The body is organized at different levels starting with cells. Cells are organized into tissues, and tissues forms into organs. Organs are organized into organ systems  What is Cell? “A cell is defined as the smallest, basic unit of life that is responsible for all of life's processes.” Cells are the structural, functional, and biological units of all living beings. Root : cyt -from New Latin -cyta, from Greek kytos container, body, hollow vessel. cyt/o = cell; -logy = study of. 1665: Robert Hooke discovered cells in cork, then in living plant tissue using an early compound microscope. He coined the term cell (from Latin cellula, meaning "small room") in his book Micrographia (1665). The cell is the basic unit of living organisms. They carry out metabolism, the sum of all the body's physical and chemical activities The main categories of organic compounds contained in cells are: 1.Proteins- which includes enzymes,some hormones and structural materials 3. Lipids-which includes fats. Some hormones are derived from lipids and adipose (fat)tissue is designed to store lipids The Cell Structures  STRUCTURAL AND FUNCTIONAL ORGANIZATION OF THE HUMAN BODY Chemical level - organization involves how atoms, such as hydrogen and carbon, interact and combine into molecules *Molecule’s structure determines its function  STRUCTURAL AND FUNCTIONAL ORGANIZATION OF THE HUMAN BODY Cell level - cell are the basic structural and functional units of organisms, such as plants and animals. Molecules can combine to form organelles, which are the small structures that make up some cells  STRUCTURAL AND FUNCTIONAL ORGANIZATION OF THE HUMAN BODY Tissue level - is a group of similar cells and the materials surrounding the. The characteristics of the cells and surrounding materials determine the functions of the tissue  STRUCTURAL AND FUNCTIONAL ORGANIZATION OF THE HUMAN BODY Organ level - is composed of two or more tissue types that together perform one or more common functions.  STRUCTURAL AND FUNCTIONAL ORGANIZATION OF THE HUMAN BODY Organ system level - group of organs classified as a unit because of a common function or set of functions. The Cell Structures  Adenosine triphosphate The Cell Structures The Cell Structures Characteristics of Life Organization: Functional interrelationships between parts Metabolism: Sum of all chemical and physical changes sustaining an organism Ability to acquire and use energy in support of these changes Responsiveness: Ability to sense and respond to environmental changes Includes both internal and external environments Anatomy and Physiology Lab Characteristics of Life Growth: can increase in size size of cells, groups of cells, extracellular materials Development: changes in form and size changes in cell structure and function from generalized to specialized- differentiation Anatomy and Physiology Lab Characteristics of Life Reproduction: formation of new cells or new organisms generation of new individuals tissue repair Anatomy and Physiology Lab Characteristics of Life Homeostasis: is the existence and maintenance of a relatively constant environment within the body despite fluctuations in either the external environment or the internal environment All homeostatic control mechanisms have at least three interdependent components for the variable being regulated: a receptor, a control center, and an effector. The receptor is the sensing component that monitors and responds to changes in the environment, either external or internal. Anatomy and Physiology Lab Characteristics of Life Homeostasis: is the existence and maintenance of a relatively constant environment within the body despite fluctuations in either the external environment or the internal environment All homeostatic control mechanisms have at least three interdependent components for the variable being regulated: a receptor, a control center, and an effector. The receptor is the sensing component that monitors and responds to changes in the environment, either external or internal. Anatomy and Physiology Lab Characteristics of Life Homeostasis: Variables: measures of body properties that may change in value Examples of variables: body temperature pH heart rate respiratory rate blood pressure blood glucose levels blood cell counts toxins Anatomy and Physiology Lab  Most negative -feedback mechanisms, such as the one that maintains normal body temperature, have : 3 COMPONENTS 1. Receptor- monitors the value of a variable, such as body temperature, by detecting stimuli 2. Control center- such as part of the brain, determines the set point for the variable and receives input from the receptor about the variable 3. Effector- such as sweat glands, can change the value of the variable when directed by the control center. Stimulus- changed variable that initiates a homeostatic mechanism. occurs when the initial stimulus further stimulates the response. deviation from the set point becomes even greater. In this case, the word “positive” indicates an increase. At times, this type of response is required to re- achieve homeostasis. Some positive feedback occurs under normal condition (ex: childbirth) Generally associated with injury, disease ex: during blood loss, a chemical responsible for clot formation stimulates production of itself. Anatomy and Physiology Lab Levels of Organization for the Human Body Tissues 1. Epithelial - tissue covers and Cells are organized into protect body structures and lines four basic types of organs, vessels and cavities. tissues that perform specific functions: From the Greek roots ἐπί (epi), "on" or "upon", and θηλή (thēlē), "nipple". Epithelium is so called because the name was originally used to describe the translucent covering of small "nipples" of tissue on the lip. Epithelial Tissue Tissues 1. Epithelial - tissue covers and Cells are organized into protect body structures and lines four basic types of organs, vessels and cavities. tissues that perform specific functions: Classification according to shape: 1. Squamous- flat and thin 2. Cuboidal- shaped like a cube (box) 3. Columnar- taller than it is wide(rectangular) Epithelial Tissue Tissues 1. Epithelial - tissue covers and protect body structures and lines organs, vessels Cells are organized into and cavities. four basic types of tissues that perform Classification according to number of layers: a. Simple epithelium-cells in single layer. It absorb specific functions: substances from one system b. Stratified epithelium- cells in multiple layers,protects deeper tissues c. Pseudostratified-single layer of irregularly shaped cells that give the appearane of more than 1 layer Epithelial Tissue Simple Squamous epithelium  Simple cuboidal epithelium - found in glandular Tissues tissue and in the kidney tubules Simple columnar epithelium lines the stomach and intestines Pseudostratified columnar epithelium lines portions of the respiratory tract and some tubes of the male reproductive tract. Transitional epithelium can be distended or stretched. Glandular epithelium is specialized to produce and secrete substances Epithelial Tissue Simple Cuboidal epithelium Nonciliated simple columnar epithelium Ciliated simple columnar epithelium Ciliated pseudo stratified columnar epithelium Stratified squamous epithelium Stratified cuboidal epithelium Stratified columnar epithelium Transitional epithelium (urothelium) Transitional epithelium (urothelium) Glandular epithelium Glandular epithelium Tissues 2. Connective tissue- supports and binds body structures. It contains fibers and other non- living material between the cells. These are blood, adipose(fat)tissue, cartilage and bone Connective Tissue Tissues Connective tissue cells are characterized by an abundance of intercellular matrix with relatively few cells. They are able to reproduce but not as rapidly as epithelial cells Connective Tissue  Classification: Tissues I. Embryonic connective tissue- present in the embryo or a fetus Connective Tissue a. Mesenchyme- present in the embryo from -consists of cells fertilization through the first two mos of pregnancy, surrounded by a and in the fetus, the developing human form the third compartment of fluid month of pregnancy B. Mucous (mucoid) connective tissue-support and called the extracellular cushion the blood vessels within the umbilical cord. matrix (ECM) Connective Tissue Connective Tissue Connective Tissue  Classification: Tissues II. Mature connective tissue A. Connective tissue proper Connective Tissue 1. Loose connective tissue -consists of cells a. Areolar connective tissue- for strength, elasticity and support surrounded by a b. Adipose tissue- reduces heat loss through skin, energy compartment of fluid reserve, supports and protects organs called the extracellular c. Reticular connective tissue -binds smooth muscle matrix tissue cells, removes worn- out blood cells in spleen and (ECM) microbes in lymph nodes Connective Tissue  Classification: Tissues II. Mature connective tissue A. Connective tissue proper Connective Tissue -consists of cells 2. Dense connective tissue- contains more fibers a. Dense regular connective tissue-forms tendons, surrounded by a ligaments and aponeuroses compartment of fluid b. Dense irregular connective tissue- provides tensile called the extracellular (pulling) strenghth in many directions (ex: fascia) matrix c. Elastic connective tissue-allows stretching various (ECM) organs, strong and can recoil to its original shape after being stretched Connective Tissue  Classification: Tissues II. Mature connective tissue B. Supporting connective tissue Connective Tissue 1. Cartilage -consists of cells a. Hyaline cartilage b. Fibrocartilage surrounded by a c. Elastic cartilage compartment of fluid 2. Bone tissue called the extracellular a. Compact bone matrix b. Spongy bone (ECM) C. Liquid Connective tissue 1. Blood 2. Lymph Connective Tissue Tissues Connective Tissue D a. adipose tissue b. cartilage c. bone D. Blood Connective Tissue Tissues 3. Muscle tissue (root: my/o) contracts to produce movement. 3 types of muscle tissues: a. Skeletal muscle - moves skeleton b. Cardiac muscle forms the heart. It functions without conscious control and is described as involuntary c. Smooth or visceral muscle forms the walls of the abdominal organs; It is also involuntary. The walls of ducts and blood vessels are also composed mainly of smooth muscle. Muscle Tissue  Muscle tissue is highly cellular and is Tissues well supplied with blood vessels. The cells are long and slender so they are sometimes called muscle fibers. and these are usually arranged in bundles or layers that are surrounded by connective tissue. Actin and myosin are contractile proteins in muscle tissue. Muscle Tissue Tissues MuscleTissue a. skeletal muscle b. cardiac muscle c. smooth muscle Muscle Tissue Tissues 4. Nervous tissue (root: neur/o) makes up the brain, spinal cord and nerves. It coordinates and controls body responses by the transmission of electrical impulses. The basic cell in nervous tissues is the neuron, or the nerve cell Nervous Tissue Tissues Nervous Tissue a. neuron b. nerves c. nervous tissue Nervous Tissue