Tissues
Tissues
Topics Covered
Introduction to Tissues
Epithelial Tissues
Connective Tissues
Muscle Tissues
Nervous Tissues
Introduction
Definitions
· Tissues - groups of cells that are similar in structure and perform a common function
· Histology - the study of tissues and how they are arranged into organs
4 Primary Tissues (linked to figure 4.2- Four types of Connective Tissue)
1. Connective Tissue
2. Epithelial Tissue
3. Muscle Tissue
4. Nervous Tissue
Epithelial Tissue
CLASSIFICATION:
· Cell Shape (Linked to figure 4.6- Cells of Epithelial Tissue)
o Squamous
o Cuboidal
o Columnar
· Cell Organization (Linked to figure 4.6- Cells of Epithelial Tissue)
o Squamous
o Simple
o Stratified
o Pseudostratified
o Transitional
Epithelial Tissue (Linked to figure 4.8- Summary of Epithelial Tissue Cells)
Simple Squamous
· Air sacs of lungs, lining blood vessels
o Smooth lining, reduces friction, allows simple diffusion
Simple Cuboidal
· Form many major glands and glandular organs, major cell type of kidney and pancreas
o Secretion of fluids or hormones (sweat, oil), re-absorption (kidneys)
Simple Columnar
· Inner portion of digestive tract, uterine tubes, often associate with Goblet cells
o Provides absorptive areas on inner portions of the digestive tract.
o Goblet cells secrete mucin.
Stratified Squamous
· Surface of skin, lining mouth, throat, esophagus, rectum, anus, and vagina.
· Provides physical protection against abrasions, pathogens and chemical attack.
Transitional
· Urinary bladder, renal pelvis, and ureters.
· Permits expansion and recoil after stretching.
Pseudostratified Columnar
· Lining of the respiratory tract and portions of the male reproductive tract.
· Protection and secretion.
· Have cilia.
Connective Tissue
CLASSIFICATION:
· Fibrous connective tissue (CT Proper) (Linked to figure 4.12- Connective Tissue Proper)
o Loose CT (reticular, areolar, adipose)
o Dense CT (dense regular, dense irregular, elastic) (Linked to figure 4.15- Dense Connective Tissues)
· Cartilage (supportive CT) (Linked to figure 4.16- Types of Cartilage)
o Hyaline cartilage
o Fibrocartilage
o Elastic cartilage
· Bone (supportive CT)
· Blood (Fluid CT)
Connective Tissue
Adipose (Linked to figure 4.13- Adipose Tissue)
· Deep in skin, padding around eyes and kidneys.
· Provides padding and cushions shock; insulates.
Blood
· Found throughout body in blood vessels.
· Transport; immune function.
Hyaline Cartilage
· Between tips of ribs and bones and trachea.
· Reduces friction between bony surfaces.
· Cells known as chondrocytes.
Bone
· Throughout body.
· Support; regulates calcium levels; immune function.
· Cells known as osteocytes.
Muscle Tissue
(Linked to figure 4.18- Muscle Tissue)
·
Skeletal
Muscle
o Cells referred to as muscle fibers
o Striated, multinucleated, voluntary
· Cardiac Muscle
o Cells referred to as myocytes
o Striated, branched, multinucleated, involuntary
o Intercalated disc
· Smooth Muscle
o Intestines (peristalsis), blood vessels, uterus, urinary tract, most organs.
o Nonstriated, involuntary
Nervous Tissue
(Linked to figure 4.20- Nervous Tissue)
Two cell types found in nervous tissue:
· Neuron (Linked to figure 4.19- The Neuron)
o Specialized cell that conducts electrochemical impulses.
o 3 main regions- dendrites, cell body (soma) and the axon.
· Glial cells or neuroglia
o Play supportive roles for neurons.