Physiology Ch 5 Lecture Notes

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