How many cells are there in your body?

37.2 trillion cells* *According to some estimations. In the past, estimations have ranged between 5 billion to 200 million trillion cells

How big is a trillion?

1,000,000,000,000

How long is a trillion seconds?

31,546 years.

Made about 30,000 years ago.

How many different TYPES of cells are there in the human body?

~200

Remember that cells make tissues.

4 main tissue types: Epithelial Connective Muscle Nervous

Epithelial Tissue Functions: Characteristics: Protection, secretion, absorption, filtration Characteristics: Avascular (no blood supply), fast to heal or repair, always includes basement membrane, found on every free body surface

Connective Tissue Functions: Characteristics: Support, protection, mechanical integrity Characteristics: Few cells surrounded by lots of nonliving stuff, slow to heal or repair

Muscle Tissue Function: Characteristics: Movement cells contract or shorten

Nervous Tissue Functions: Characteristics: Sensing and transmitting information Characteristics: Cell body with lots of stuff sticking off of it

Naming Epithelial Cells Epithelial cells are named based on two things: How many layers Shapes of cells

Classification of Epithelia Number of cell layers Simple—one layer Stratified—more than one layer

Why are they called this?

Classification of Epithelia Shape of cells Squamous= flattened (pancakes) Cuboidal = cube Columnar =column

Types of Connective tissue! Connective tissue is the most common type of tissue in the body! Examples include: Bone Blood Fat Cartilage

The surface of your skin!

Colored scanning electron micrograph (SEM) of human skin Stratum Corneum Stratum Basale Dermis

Process of Keratinization Cells divide in Stratum Basale and push older cells up to surface. Cells starve and die as pushed away from dermis.

How is this child's skin different from yours?

Defect in keritinization causes over shedding of cells Netherton Syndrome Defect in keritinization causes over shedding of cells

Skin Structure

Melanin Absorbs UV radiation which protects the deeper tissues Tanning and dark skin color comes from melanocytes producing more melanin NOT due to more melanocytes

http://www.cnn.com/2015/11/15/health/face-transplant-firefighter/

Dermis

The dermis contains many different touch receptors The dermis contains many different touch receptors. Different types of touch have different receptors.

The dermis contains Proteins make skin strong yet elastic Blood vessels in dermis help skin control body temperature. Elastic Man https://www.youtube.com/watch?v=f46SpiboAew

Vessels in Dermis Provides blood supply/nutrients to all skin cells. Control temperature by getting larger or smaller.

Burns

Burns Tissue damage and cell death caused by heat, electricity, UV radiation, or chemicals Associated dangers Dehydration Electrolyte imbalance Circulatory shock

Burn classification based upon what layer(s) of tissue have been damaged 1st- Epidermis 2nd- Dermis 3rd- Hypodermis

Burn symptoms First-degree burns Second-degree burns Only epidermis is damaged Skin is red and swollen Second-degree burns Epidermis and upper dermis are damaged Skin is red with blisters Third-degree burns Destroys entire skin layer Burn is gray-white or black

Severity of Burns Figure 4.11b

WARNING! GRAPHIC CONTENT!

Caption: Tissue expanders Caption: Tissue expanders. Inflated tissue expanders in the back of a 12-year-old boy with extensive scarring after third degree burns. Tissue expanders are used to stretch the skin prior to skin grafting. The expanders are surgically implanted under the skin and gradually inflated over several months, forcing the skin to stretch over a wider area. The spare skin is then cut out and grafted over another part of the body, in this case to cover scars caused by third degree burns. Severe burns cause permanent scars that can never be completely hidden. In children the scar tissue stretches and tears as the child grows, making continual medical attention necessary.

Skin Homeostatic Imbalances

Athlete’s foot - fungal infection

Boils and carbuncles - bacterial infection

Cold Sores – Caused by virus

Contact dermatitis Exposures cause allergic reaction

Psoriasis – Cause unknown/ Autoimmune Psoriasis – Cause unknown/ Autoimmune? Triggered by trauma, infection, or stress

Acne is an active infection of the sebaceous glands.

Follicle becomes blocked which allows bacteria to proliferate Follicle becomes blocked which allows bacteria to proliferate. Body responds to infection. Rarely happens with sweat glands.

Skin Cancer Cancer—abnormal cell mass Classified two ways Benign Does not spread (encapsulated) Malignant Metastasized (moves) to other parts of the body Skin cancer is the most common type of cancer

Xeroderma Pigmentosum Inherited genetic disorder in which the mechanisms which repair DNA after UV damage are deficient or absent. Leads to EXTREME susceptibility to skin cancer.

Skin Cancer Caused by UV radiation causing direct or indirect damage to DNA of the cells.

Skin Cancer Types Basal cell carcinoma Least malignant Most common type Arises from stratum basale

Skin Cancer Types Figure 4.12a

Skin Cancer Basal Cell Carcinoma – least malignant (99% survival), arises from cells in the stratum basale, Malignant Melanoma- can be aggressive, arises from melanocytes

Skin Cancer Types Squamous cell carcinoma Metastasizes to lymph nodes if not removed Early removal allows a good chance of cure Believed to be sun-induced Arises from stratum spinosum

Skin Cancer Types

Skin Cancer Types Malignant melanoma Most deadly of skin cancers Cancer of melanocytes Metastasizes rapidly to lymph and blood vessels Detection uses ABCD rule

Skin Cancer Types Figure 4.12c

ABCD Rule A = Asymmetry B = Border irregularity C = Color D = Diameter Two sides of pigmented mole do not match B = Border irregularity Borders of mole are not smooth C = Color Different colors in pigmented area D = Diameter Spot is larger then 6 mm in diameter

ABCDE rule A- Asymmetry Halves don’t match

ABCDE rule B- Border irregularity Borders are not smooth

ABCDE rule C- Color Spot contains several colors

ABCDE rule D- Diameter Larger than a pencil eraser

WARNING! GRAPHIC CONTENT!

Making Tissues https://www.youtube.com/watch?v=4mHFKynA_gc https://www.youtube.com/watch?v=eZ6GQfXEmyM

How do we get from one cell to trillions? 1:15 – 4:30 http://www.bozemanscience.com/044-cellular-specialization

Tissue Types hand out Tissue types graphic organizer Tissue Art project

Tissue Gallery Pick a tissue type Pick an Art style Create a poster that has: A title A printed picture of your tissue type An artistic representation of that tissue type in the art style of your choice Description of the tissue Function of the tissue Locations of the tissue A description of what about the tissue inspired your piece. Mount artwork and photo with information on colored paper. Art will be displayed and judged in 3 categories: "Most Creative" "True To Tissue" "True To Impressionism" http://www.cpalms.org/Public/PreviewResourceLesson/Preview/46144

Epithelium Characteristics