CHAPTER 5:
TISSUES
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Tissue - cells with the same structure andfunction
4 Major Types
1. epithelial
2. connective
3. muscle4. nerve
cytoplasm
Epithelial Tissue
- covers all body surfaces, inside & out- always connected to a non-living materialcalled the basement membrane
- easily reproduced- heal rapidly
1. Simple Squamous Epithelium
- single layer of thin flat cells
- easily allows for diffusion
- found in air sacs in the lungs, walls ofblood capillaries, & inside wall of blood vessels
2. Simple Cuboidal Epithelium
- single layer of cubed-shaped cells
- covers ovaries, lines kidney tubes & glands
- involved in secretion & absorption in the kidney and glands
3. Simple Columnar Epithelium- single layer of elongated cells
- lining of the uterus & organs of the digestive tract
- have microvilli to increase the absorptionof nutrients
- contain goblet cells - secretes mucus
4. Pseudostratified Columnar Epithelium
- single layer of cells that looks like manylayers
- nuclei are not lined up in a row- usually has cilia and goblet cells- lines tubes of respiratory system andreproductive system
- moves mucus or egg cells
5. Stratified Squamous Epithelium
- many layers of thin, flat cells
- cell reproduction occursin deep layers & pushesup older cells
- found in the skin
- as skin cells age, they produce keratin
- found in the mouth, throat, & anal canal
6. Stratified cuboidal epithelium- consists of 2 or 3 layers of cubed-shaped cells
- lines the larger ducts of the mammaryglands, sweat glands, and salivaryglands
7. Stratified columnar
- consists of several layers of columnarcells
- located in male urethra, vas deferens,and pharynx
8. Transitional Epithelium
- has many layers that can change in thick-ness in response to tension
- found in the lining of the bladder andurinary system
- prevents diffusion of urine
9. Glandular Epithelium
- produces and secretes substances
- exocrine glands - releases substances intosmall tubes called ducts
- endocrine glands - releases substances intothe bloodstream
Connective Tissue
- most common type
- cells are farther apart and have anabundance of extracellular matrix
- this matrix can be protein fibers, fluids, orother molecules
Connective Tissue Fibers
- produced by fibroblasts
a) collagenous fibers
- made of collagen- holds structures together - strong- ex. tendons- referred to as the white fibers
b) elastic fibers
- made of elastin- ex. vocal cords- referred to as the yellow fibers
1. Loose Connective Tissue
- connective fibers are far apart
- forms a thin membrane between organs- found beneath the skin and between muscles
2. Fibrous Connective Tissue
- densely packed connective fibers
- ligaments connects bone to bone- tendons connects muscle to bone
3. Adipose Tissue
- fat tissue
- fat stored in adipocytes
- 18% in men- 28% in women
Functions- act as an insulator- reserve energy supply
4. Cartilage
- functions for support- chondrocyte - cartilage cells- the perichondrium surrounds the cells
3 Types
a) hyaline cartilage
- found at the ends of bones at joints
- nose
- supporting rings of trachea- development of bones
b) elastic cartilage
- contains elasticfibers in matrix
- found in the earsand parts of thelarynx
c) fibrocartilage
- acts as a shockabsorber
- found in the knee,disks of the backbone, & pelvic girdle
5. Bone
- most rigid tissue
- provides internal support
- the bone cells, osteocytes, are arranged incircles called osteons
6. Blood
- a liquid tissue
- made up of red blood cells (RBC), white blood cells (WBC), and platelets
Types of Membranes- there are 3 epithelial membranes and 1connective membrane
1. Serous Membrane
- lines body cavities that lack outside openinings
- covers organs within cavities- produces a fluid called serous fluid
2. Mucous membranes
- lines body cavities with an opening tothe outside
- nasal, urinary, and reproductive tracts- goblet cells produce a fluid called mucus
3. Cutaneous membranes
- the skin- produces a fluid called sebum
4. Synovial membrane
- usually found at joints- produces synovial fluid
- made up of contracting muscle fibers
Muscle Tissue
1. Skeletal Muscle Tissue
- also called striated or voluntary muscle- contains many nuclei- are attached to bone
2. Smooth Muscle Tissue
- lacks striations- also called involuntary- only one nucleus per cell
- found in the walls of hollow internal organssuch as the stomach, intestines, bladder, and blood vessels
3. Cardiac Muscle Tissue
- found only in the heart
- only 1 nucleus per cell- some striations- contain intercalated disks which connects2 cardiac cells
Nerve Tissue
- consists of the brain, spinal cord, andnerves
2 Types of Cells
a) Neuroglial cells
- bind & support nerve tissue- carry on phagocytosis- connect neurons to blood vessels
b) Nerve cells called neurons
- coordinate and regulate body functions