Chapter 4 Tissues

Anatomy and Physiology

• Epithelial-covers body surfaces

• Connective-protects, supports, immunity

• Muscular-movement

• Nervous-detects change, homeostasis

Types of Tissues

*TWO TYPES*COVERING AND LINING*GLANDULAR

Epithelial Tissue

General Features• Closely packed cells with little in between

them

• Apical (superficial), lateral and basal layers (deep)

• Avascular- lack blood vessels

• Have a nerve supply

• High renewal and cell division

Shapes of Epithelium

• Squamous-flat like tiles, thin

• Cuboidal-tall and wide, sometimes contain microvilli, function in secretion and absorption

Shapes• Columnar- very tall, protect underlying

tissues, may have microvilli or cilia, secretion and absorption.

• Transitional- change their shape as the organs stretch

Simple Epithelium

• This is a single layer of cells found in areas where diffusion, osmosis, filtration, secretion, and absorption occur.

• Simple squamous

• Simple Cuboidal

• Simple Columnar

Stratified Epithelium

• Contains two or more layers of cells used for protection of underlying tissues.

• Stratified squamous

• Stratified cuboidal

• Stratified columnar

• Transitional-variable in appearance

Pseudostratified Epithelium

• All cells are connected to basement membrane but some do not reach the surface therefore from the side, it gives the impression of layers.

Glandular Epithelium

• Main function is to secrete materials.

• A gland can consist of one cell or group of cells .

• Endocrine-release into the body

• Exocrine-release outside the body

Vocabulary Cards

Basement membrane

Avascular

Squamous

Cuboidal

Columnar

Transistional

Simple

Stratified

pseudostratified

6 TYPES*LOOSE*DENSE*CARTILAGE*BONE*BLOOD*LYMPH

Connective Tissue

General Features• The matrix is the material between the

widely spaced cells.

• All connective tissue except cartilage has a nerve supply.

• It is highly vascular except for cartilage.

Connective Tissue Cells• Fibroblasts-large, flat and branching, most

numerous, secrete fibers

• Macrophages- irregular shape, and engulf bacteria and debris by phagocytosis, may be free or fixed

Connective Tissue Cells

• Mast cells- produce histamine in response to injury

• Adipocytes- fat cells that store fats below the skin and around organs.

Connective Tissue Matrix

• Ground substance- between cells, binds them together, supports cells, contain hyaluronic acid to lubricate and bind the cells.

• Fibers- 3 types- collagen, elastic and reticular

Fibers*Collagen- most abundant protein in the body, strong but flexible

*Elastic- contain elastin and fibrillin,

strong but very flexible

*Reticular- thinner and form the basement membrane and support the soft organs like the spleen and lymph nodes.

Loose Connective Tissue• Areolar-widely distributed, contains all

three types of fibers, strength, elasticity and support

• Adipose- contain adipocytes, store fat under the skin and around organs

• Reticular-forms soft organs and smooth muscle cells

Dense Connective Tissue• Regular- collagen arranged in a regular

pattern of bundles for strength

• Irregular- collagen fibers are irregular arranged and often pulled in many directions

• Elastic- strong and can recoil to original shape, lung and heart

Cartilage• Cells are called chondrocytes.

• Contain collagen and chondroitin sulfate for strength and elasticity.

• Hyaline-most abundant, reduces friction and absorbs shock, joints

• Fibrocartilage- very strong and rigid, discs between vertebrae.

• Elastic- very flexible, ear and nose

Bone Tissue• Cells are called osteocytes.

• Haversion canal contains blood supply.

• Two types: compact and spongy

• Bone supports soft tissues, protects delicate structures, allows for movement with muscles and produces bone marrow for immunity.

Blood Tissue• Has a liquid matrix called blood

plasma.

• Red blood and white blood cells are present.

• Platelets participate in blood clotting.

• Lymph-fluid that flows in lymphatic vessels, clear

MUSCULAR TISSUE3 TYPES*SKELETAL*CARDIAC*SMOOTH

Skeletal Muscle

• Attached to bones of the skeleton

• Striated-contains bands of muscle

• voluntary

Cardiac Muscle• Striated and very strong

• Involuntary

• Found only in the heart

• Fibers are more branched

Smooth Muscle

• Located in walls of organs, blood vessels and airways

• Involuntary

• Non-striated (smooth)

Vocabulary Cards

Fibroblasts

Macrophages

Mast cells

Adipocytes

Ground substance

Loose connective tissue

Dense connective tissue

Cartilage

striated

The Skin is AWESOME!

• The skin or cutaneous membrane covers the external surface of the body.

• It’s the largest organ!

• 16% of total body weight!

Structure of the skin

• Two main parts

• Epidermis-superficial

• Dermis-deep

• Deep to the dermis but not part of the actual skin is the subcutaneous layer, serves as an anchor

Epidermis

• Keratinized stratified squamous epithelium

• Contains 4 types of cells

• Keratinocytes-produce keratin

• Melanocytes-color of skin

• Langerhans cells-immune response

• Merkel cells-touch sensations

Epidermal Layers

• Stratum basale-deepest, cell division

• Stratum spinosum

• Stratum granum-water repellent, sealant

• Stratum lucidum-dead cells on fingertips, palms and soles

• Stratum corneum-protection

Skin Color• Melanin, carotene and hemoglobin are

three pigments that impart a wide variety of colors to the skin.

• Melanocytes create melanin and most people have around the same number of these.

• Exposure to UV light stimulate melanin production

• Repeated exposure can cause skin cancer.

Hair (pili)

• Each hair is a thread of fused, dead keratinized cells that consist of a shaft and a root.

• Surrounding the root is the hair follicle.

• Arrector pili are smooth muscles in the hair follicle and cause goosebumps to occur.

Glands• Sebaceous glands-oil glands

(sebum), open to hair follicles, not found in palms and soles, excessive sebum accumulation can result in acne.

Glands• Sudoriferous glands-sweat glands,

two types, eccrine (normal sweat glands) and apocrine(thicker sweat normally found in armpits and genital areas (cold sweat)

• Ceruminous-ear canal, wax

Nails• Nails are tightly packed, hard,

keratinized cells of the epidermis.

• The white area that looks like a moon is the lunula.

• The cuticle is the tiny flap of skin that protects the nail root.

Vocabulary Cards

Epidermis

Dermis

Melanocytes

Keratinocytes

Arrector pili

Lunula

Sebaceous glands

Sudiferous glands

Ceruminous glands

Chapter 17 The Immune System

Anatomy and Physiology

Lymphatic System• Drain excess fluid.

• Transport dietary lipids.

• Carry out immune response.

• Consist of veins and capillaries similiar to blood vessels.

• Contain lymph nodes to filter interstitial fluid.

Lymphatic organs and tissues• Thymus- two-lobed organ, located medial

to the lungs and superior to the heart, contains T cells and macrophages, clear dead and dying cells

• Lymph nodes- 600 bean shaped nodes, B cells, T cells, macrophages, filter lymph and circulate lymph through valves and vessels

Lymphatic Organs and Tissues

• Spleen- between stomach and diaphragm, lymphocytes and macrophages, macrophages destroy pathogens, storage of platelets, production of fetal blood cells, B and T cells carry out immune responses

Lymphatic Organs and Tissues

• Lymphatic nodules are egg shaped, tonsils

• 5 tonsils

• Pharyngeal, adenoid, two palatine tonsils (obvious ones) 2 lingual tonsils at the base of the tongue.

Barrier Defenses-non-specific

• External barriers prevent pathogens from entering the body:

• Skin• Mucous membranes• Saliva• Tears

• Cilia• Hair• Sweat• oil

Internal Defenses

• Interferon- protein that interferes with virus replication

• Complement system- proteins that enhance other immune responses, normally inactive

• Natural killer cells- kills microbes and tumors

• Phagocytes- ingest microbes

• Macrophages- developed from monocytes, eat microbes

Inflammation and Fever Responses• Helps prevent the spread of microbes.

• Allows more blood to flow to the injury site.

• Helps remove toxins.

• Carries immune cells to the site faster

• Fever is caused by interleukins.

• Elevated body temperature increases the effects of interferon, and speeds up bodily reactions and repair.

Vocabulary Cards

Inflammation

Interferon

Macrophage

Natural killer cells

phagocyte

Lymphocytes-Specific response

• B and T cells.

• Contain antigen receptors.

• Cell-mediated response- directly attack invaders

• Antibody mediated response- release antibodies against the microbe.

Antigens and Antibodies• An antigen causes the body to produce

antibodies.

• Specific T cells will react to certain proteins and toxins.

• MHC molecules (major histocompatibility complex)-unique proteins that identify you to help T cells recognize foreign invaders.

• Major roadblock to organ transplantation.

Antigens and Antibodies• Antigens induce plasma cells to secrete

proteins called antibodies against them.

• The antibody fits against the antigen on the surface of the microbe.

• Antibodies belong to a group of proteins called immunoglobulins.

• Each has a distinct function and chemical structure.

T Cells• The presence of antigens inform

the T cells to begin attack but it only becomes active once the foreign antigen binds with it.

• APC or antigen presenting cell must ingest a foreign antigen, process it and present it to a T cell for recognition. Dendritic cells, helper T cells and macrophages can do this.

T Cells• T cells also need a second stimulator

to prevent false alarms. Interleukin does this.

• Once activated, the T cell clones itself into an army.

• Causes swollen lymph nodes.

3 types of T Cells

• Helper T cells release interleukins and also offer antigens.

• Cytotoxic T cells kill cells that are infected with precision using enzymes.

• Memory T cells remain in the body to prevent reinfection.

B cells• Usually stay in the lymph nodes.

• Secrete antibodies once activated by T cells and interleukins.

• Can receive unprocessed antigens but respond faster to processed ones

• Can become memory cells to respond to the same antigen in the future

Immunity• Naturally Acquired Active- get sick,

memory cells remember and prevent future attacks

• Naturally Acquired Passive- Antibody transfer from mother to fetus across placenta, or breastfeeding

Immunity• Artificially Acquired Active- vaccinations

cause an immune response without causing sickness, usually involves injecting antigens or weakened viruses

• Artificially Acquired Passive- injection of immunoglobulins (antibodies)

Vocabulary Cards

B cell

T cell

Antigen

Antibody

Memory cell

Vaccine

MHC

APC (antigen processing cell)

40 total cards