Lecture Outline
Adapted from Martini Human Anatomy 7th ed. / Session:
Section:
Days / Time: Instructor: / FALL
52999
MW 5:00 PM – 9:20 PM
RIDDELL
Chapter 3
Foundations: Tissues and Early Embryology
Introduction
Atoms make up molecules
Molecules make up cells
Cells make up tissues
Tissues make up organs
Organs make up organ systems
Organ systems make up organisms
Introduction
This chapter concentrates on cells and tissues
There are over 75 trillion cells in the body
All cells can be placed into one of the four tissue categories
Epithelial tissue
Connective tissue
Muscular tissue
Neural tissue
Epithelial Tissue
Epithelial Tissue Characteristics
Cellularity
Cells are bound close together
No intercellular space
Polarity
Have an exposed apical surface
Have an attached basal surface
Epithelial Tissue
Epithelial Tissue Characteristics (continued)
Attachment
Basal layer is attached to the basal lamina
Avascularity
Do not consist of blood vessels
Epithelial Tissue
Epithelial Tissue Characteristics (continued)
Arranged in sheets
Composed of one or more layers of cells
Regeneration
Cells are continuously replaced via cell reproduction
Epithelial Tissue
Functions of Epithelial Tissue
Provides physical protection
Controls permeability
Provides sensation
Produces secretions
Epithelial Tissue
Specialization of Epithelial Cells
Microvilli
For absorption and secretion
Stereocilia
Long microvilli, commonly found in the inner ear
Ciliated epithelium
Moves substances over the apical surfaces of the cells
Epithelial Tissue
Maintaining the Integrity of the Epithelium
Three factors involved in maintenance
Intercellular connections
Attachment to the basal lamina
Epithelial maintenance and renewal is self-perpetuated
Epithelial Tissue
Classification of Epithelia
Simple
Epithelium has only one layer of cells
Stratified
Epithelium has two or more layers of cells
Epithelial Tissue
Epithelial Tissue Cells
Squamous cells
Thin, flat cells / “squished” nuclei
Cuboidal cells
Cube-shaped cells / centered, round nucleus
Columnar cells
Longer than they are wide / nucleus near the base
Transitional cells
Mixture of cells / nuclei appear to be scattered
Epithelial Tissue
Simple Squamous Epithelium
Consists of very delicate cells
Location
Lining body cavities, the heart, the blood vessels
Function
Reduces friction
Absorbs and secretes material
Epithelial Tissue
Stratified Squamous Epithelium
Location
Surface of skin
Lines: mouth, esophagus, anus, vagina
Function
Protection
Epithelial Tissue
Simple Cuboidal Epithelium
Location
Thyroid gland, ducts, kidney tubules
Function
Secretion, absorption
Epithelial Tissue
Stratified Cuboidal Epithelium
Location
Ducts of sweat glands
Function
Secretion, absorption
Epithelial Tissue
Simple Columnar Epithelium
Location
Lining: stomach, intestines, uterine tubes
Function
Secretion, absorption, protection
Epithelial Tissue
Stratified Columnar Epithelium
Location
Pharynx, epiglottis, mammary glands, salivary glands
Function
Protection
Epithelial Tissue
Pseudostratified Ciliated Columnar Epithelium
Nucleus situated at different levels
Location
Nasal cavity, trachea, bronchi
Function
Protection, secretion
Epithelial Tissue
Transitional Epithelium
Consists of many layers
Consists of a combination of cuboidal and “odd” shaped cells
Location
Urinary bladder
Function
Ability to stretch extensively
Epithelial Tissue
Glandular Epithelia
Many epithelia are mixed with gland cells
Types of glands
Serous glands: secrete watery fluids rich in enzymes
Mucous glands: secrete glycoproteins (mucins) that absorb water to produce mucus
Mixed exocrine glands: contain both serous and mucous secretions
Epithelial Tissue
Glandular Epithelia (continued)
Endocrine glands
Secretions enter into the blood or lymph
Exocrine glands
Secretions travel through ducts to the epithelial surface
Epithelial Tissue
Glandular Epithelia Classification
Simple glands
Do not have branching ducts
Compound glands
Have various branching ducts
Epithelial Tissue
Glandular Epithelia
Modes of Secretion
Merocrine secretion
Apocrine secretion
Holocrine secretion
Epithelial Tissue
Modes of Secretion
Merocrine Secretion
Secretions released through exocytosis
Examples:
Goblet cells of the trachea
Cells in the axilla region regarding sweat production
Epithelial Tissue
Modes of Secretion
Apocrine Secretion
Secretions released via the loss of cytoplasm
Example:
Cells of the mammary glands for milk secretion
Epithelial Tissue
Modes of Secretion
Holocrine Secretion
Secretions released upon bursting of the glandular cells
Example:
Cells of the sebaceous glands
Connective Tissues
All connective tissues have three main components:
Specialized cells
Extracellular protein fibers
Matrix
The matrix is the collective term for the extracellular component of any connective tissue that is made of protein fibers and the ground substance
Connective Tissues
Functions of Connective Tissue
Establishing the structural framework of the body
Transporting fluid and dissolved materials
Protecting organs
Supporting, surrounding, and connecting other tissues
Storing energy
Defending the body from microorganisms
Connective Tissues
Classification of Connective Tissue
Connective tissue proper
Has a matrix of fibers (loose fibers and dense fibers)
Fluid connective tissue
Has a matrix of liquid (blood and lymph)
Supporting connective tissue
Has a matrix consisting of a gel or a solid (cartilage and bone)
Connective Tissue Proper
Connective Tissue Proper
Loose fibers
Areolar tissue
Adipose tissue
Reticular tissue
Dense fibers
Dense regular
Dense irregular
Elastic
Connective Tissue Proper
Areolar Tissue (details)
Location
Deep dermis
Between muscles
Function
Connects skin to muscle
Matrix
Fibers
Connective Tissue Proper
Adipose Tissue (details)
Location
Hypodermis
Buttocks, surrounds organs
Function
Cushion
Insulation
Matrix
Fibers
Connective Tissue Proper
Reticular Tissue (details)
Location
Liver, spleen, kidney, lymph nodes, tonsils, appendix, bone marrow
Function
Supporting framework
Matrix
Fibers
Connective Tissue Proper
Dense Regular Connective Tissue (details)
Location
Tendons, aponeuroses, ligaments
Elastic tissue
Function
Tendons: connect muscle to bone
Aponeuroses: connect muscle to muscle or covers entire muscle
Ligaments: connect bone to bone
Elastic: stabilizes the vertebrae
Matrix
Fibers
Connective Tissue Proper
Dense Irregular Connective Tissue (details)
Location
Nerve and muscle sheaths
Function
Provides strength
Matrix
Fibers
Fluid Connective Tissue
Fluid Connective Tissue
Blood
Erythrocytes
Leukocytes
Platelets
Plasma
Fluid Connective Tissue
Blood (details)
Location: circulatory system
Erythrocytes
Transport oxygen and carbon dioxide
Leukocytes
Fight infections
Platelets
Blood clotting
Matrix
Liquid (plasma)
Fluid Connective Tissue
Lymph (details)
Location
Lymphoid system
Lymphocytes
Develop into T cells and B cells (for example)
Function
Involved with the immune system
Supporting Connective Tissue
Supporting Connective Tissue
Cartilage and Bone
Provide a strong framework that supports rest of body
Supporting Connective Tissue
Cartilage
Types of Cartilage:
Hyaline cartilage
Elastic cartilage
Fibrous cartilage
Supporting Connective Tissue
Hyaline Cartilage Tissue (details)
Location
Between bones at the joints
Tracheal cartilage rings
Function
Flexible support
Reduces friction
Matrix
Gel
Supporting Connective Tissue
Elastic Cartilage Tissue (details)
Location
Auricle of the ear
Function
Flexible support
Matrix
Gel
Supporting Connective Tissue
Fibrous Cartilage Tissue (details)
Location
Pads within the knee joints
Pubic symphysis
Function
Resists compression
Matrix
Gel
Supporting Connective Tissue
Bone
Location
Skeletal system
Function
Support and strength
Matrix
Solid (lamellae)
Supporting Connective Tissue
Bone (details)
Made of osteons
Osteons consist of:
Central canal
Osteocytes
Lacunae
Canaliculi
Matrix of lamellae
Membranes
Membranes
Epithelia and connective tissue combine to form membranes
Each membrane consists of:
Sheet of epithelial cells
An underlying connective tissue
Membranes
Four Types of Membranes
Mucous membrane: lines digestive and respiratory tract
Coated with mucus secretions
Has connection to the exterior of the body
Serous membrane: lines pleural, pericardial, and peritoneal cavities
Produces transudate to reduce friction
Membranes
Four Types of Membranes (continued)
Cutaneous membrane: makes up the skin
Thick and waterproof
Synovial membrane: lines the joint cavities
Produces synovial fluid that reduces friction within the joints
The Connective Tissue Framework of the Body
Connective tissue creates the internal framework of the body
Layers of connective tissue connect organs with the rest of the body
Layers of connective tissue are called fascia
Superficial fascia
Deep fascia
Subserous fascia
Muscle Tissue
Three types of muscle tissue
Skeletal muscle
Has striations
Smooth muscle
Ends of the cells are pointy
Cardiac muscle
Has intercalated discs
Muscle Tissue
Skeletal muscle
Muscles that move the skeleton
Voluntary control
Smooth muscle
Muscles that line the digestive tract, respiratory tract, and blood vessels
Involuntary control
Cardiac muscle
Found in the myometrium of the heart
Muscles cells that contract rhythmically
Neural Tissue
Neural Tissue
Specialized to conduct electrical signals through the body
Two types of neural cells
Neurons are the cells that actually transmit the impulse
Neuroglia are the supporting cells of the neural tissue; these cells protect the neurons
Tissues, Nutrition, and Aging
Repair and maintenance become less efficient as one ages
Hormonal changes and lifestyle changes also affect the functioning of tissues
Epithelia become thinner and connective tissues become fragile
Cardiac muscle cells and neural tissue cannot regenerate; therefore, relatively minor damage adds up over time, sometimes causing severe health issues
Embryology Summary
A zygote multiplies to form a ball of cells
The ball of cells develops into a hollow ball (day 6)
Blastocyst
The blastocyst forms two layers of cells
Trophoblast
The two layers of cells develop the four tissues of the body
Embryology Summary
Epithelial tissue develops to form:
Functional epithelial linings
Exocrine cells
Endocrine cells
Embryology Summary
Origins of Connective Tissues
Endoderm forms mesenchyme
Mesenchyme differentiates to form the various connective tissue categories
Embryology Summary
Development of Organ Systems
An ectoderm layer and endoderm layer form
Cells migrate between those two layers forming a mesoderm
Organs begin to develop around day 28
© 2012 Pearson Education, Inc. Page 1 of 10 BIO 218 F 2012 CH 03 Martini Lecture Outline