A&P lab (week 2)

Histology

the study of tissue (two or more types of cells sharing a common function)

Tissues have what two basic parts?

living and nonliving parts

cells (living)

the matrix (nonliving)

What is the matrix composed of?

ground substance and fibers

What are the four main tissue types?

epithelial

connective

muscular

nervous

What are the characteristics of epithelial tissue?

• tightly packed with little matrix

• avascular (not own blood supply)

• covers and lines (makes up glands)

• anchored to a basement membrane

• basal and apical surface (down and up, respectively)

• classified by number of cell layers

  • simple, stratified

• classified by cell shape

  • squamous, cuboidal, columnar

Can epithelial tissue function without a blood supply?

no, it has a connective tissue layer beneath to provide nutrients

How can you distinguish between epithelial and connective tissue?

epithelial tissue has both a basement membrane and an open space while connective does not

Pseudostratified tissue

appears stratified but is actual simple (every cell touches basement membrane)

Simple Squamous Epithelium

*location

Lines alveoli (air sacs) of lungs, blood vessels, and inside of heart

Simple Cuboidal Epithelium

*location

Lines glands and ducts; lines tubules of kidneys

Simple Columnar Epithelium

*location

lines digestive tract

Pseudostratified Ciliated Columnar Epithelium

*location

Lines respiratory passages

What are the two types of stratified squamous epithelium?

*location

non-keratinized (lines mouth, esophagus, vagina, and anal canal)

keratinized (epidermis)

What are the characteristics of Connective tissue?

• Loosely packed cells with abundant matrix

• Ground substance is fluid, gel, or solid

• Contains fibers (collagen, elastic, reticular)

• Vascular (own blood supply)

• Most abundant tissue

• Most varied in structure and functions

What are the connective tissue cell types?

fibroblasts (produce something)

mast cells (cause inflammation)

macrophages (carry out phagocytosis)

Dense Fibrous Connective tissue

two types

dense regular and dense irregular connective tissue

Dense Regular connective tissue

collagen fibers smooshed together, moving in same direction

ex. makes up tendons and ligaments

Dense irregular connective tissue

collagen fibers smooshed together, moving in opposite directions

ex. found in dermis of skin

Areolar Connective tissue

Composed of all three types of cells and fiber types

ex. found in dermis of skin

Adipose Connective tissue

Cells are adipocytes (only visible cell type)

Has all fibers (not visible)

ex. found in hypodermis (under skin) and around eyes, heart, kidneys

function: insulation and protection

Cartilage

three types

hyaline, fibrocartilage, elastic cartilage

What are the cells of cartilage?

chondrocytes

ex. found in lacunae (spaces)

Hyaline Cartilage

glass like cartilage

Has collagen but cannot see

Chondrocytes in lacunae are randomly scattered

Trachea, fetal skeleton, articular and costal cartilage

Function: does not stretch easily

Fibrocartilage

• contains thick visible collagen fibers

• neat rows (fibers line up)

ex. located in pubic symphysis, intervertebral discs, menisci of knee

function: resists compression and absorbs shock

Elastic cartilage

• contains elastic fibers (no collagen)

• chondrocytes are randomly scattered

• wispy appearance

• located in external ear + epiglottis

ex. surrounded by perichondrium

function: flexible

What are elastic and most hyaline cartilages surrounded by?

perichondrium

What are the two types of bone?

1. spongy bones

2. compact bone

ex. both types contain collagen fibers

What are the cells and basic units of bone?

unit: osteon

cells: osteocytes

Osteon

located in bone

contain central canals (holes within middle) with osteocytes scattered around (not round)

What are the different components of blood?

1. RBCs

2. WBCs

3. Platelets (clott blood)

4. Plasma (liquid portion)