What is homeostasis?
The body’s ability to maintain a stable internal environment.
Give examples of directional terms.
Superior/inferior, anterior/posterior, medial/lateral, proximal/distal, superficial/deep.
What are the 6 main elements that make up most of the human body?
Oxygen (O), Carbon (C), Hydrogen (H), Nitrogen (N), Calcium (Ca), Phosphorus (P).
Function of Oxygen?
Needed for cellular respiration and energy (ATP) production.
Function of Carbon?
Forms the backbone of all organic molecules.
Function of Hydrogen?
Found in water and organic molecules; affects pH balance.
Function of Nitrogen?
Component of proteins and nucleic acids (DNA/RNA).
Function of Calcium?
Strengthens bones/teeth, helps with muscle contraction, nerve signaling, and clotting.
Function of Phosphorus?
Part of bones, ATP (energy), and nucleic acids.
What are the 3 main subatomic particles and their charges?
Protons (+), Neutrons (0), Electrons (–).
Where are protons, neutrons, and electrons located?
Protons/neutrons in nucleus; electrons orbit around nucleus.
How do you find the number of protons?
Equal to the atomic number.
How do you find the number of electrons in a neutral atom?
Same as number of protons.
How do you find the number of neutrons?
Atomic mass – atomic number.
What determines chemical reactivity?
The number of electrons in the outer shell.
What are the 4 primary tissue types?
Epithelial, connective, muscle, and nervous tissue.
Function of epithelial tissue?
Protection, absorption, secretion, filtration.
Examples of epithelial tissue?
Simple squamous (lungs), stratified squamous (skin), simple columnar (digestive tract), transitional (bladder).
What kind of tissue makes up epithelium?
Stratified squamous.
Function of connective tissue?
Support, binding, protection, transport.
Examples of connective tissue?
Bone, blood, cartilage, adipose, areolar.
What is found in the hypodermis?
Loose connective tissue with adipose (fat) cells.
Do adipocytes (fat cells) divide in adults?
No, they grow/shrink but do not undergo mitosis.
Function of muscle tissue?
Movement and contraction.
Function of nervous tissue?
Communication via electrical impulses.
What should you be able to do with tissue microscope images?
Identify tissue types and structures (simple columnar, stratified squamous, adipose, etc.).
What are the 3 main layers of the skin?
Epidermis, Dermis, Hypodermis.
What is found in the dermis?
Hair follicles, sweat glands, sebaceous glands, and blood vessels.
What is primarily found in the hypodermis?
Adipose (fat) and loose connective tissue.
What are the functions of the integumentary system?
Protection, temperature regulation, sensation, vitamin D production, excretion.
What does sunlight help produce in the skin?
Vitamin D, which helps the body absorb calcium.
How many layers does thin skin have?
4 layers.
How many layers does thick skin have?
5 layers (includes stratum lucidum).
List the layers of the epidermis (superficial → deep).
Stratum Corneum, Stratum Lucidum, Stratum Granulosum, Stratum Spinosum, Stratum Basale. (“Come Let’s Get Sun Burned”)
Which layer is only found in thick skin?
Stratum Lucidum.
Which layer is the thickest overall?
Dermis (Corium).
Function of sebaceous glands?
Produce sebum (oil) to moisturize and protect skin/hair.
Function of eccrine sweat glands?
Found all over body; secrete watery sweat for cooling; odorless.
Function of apocrine sweat glands?
Found in armpits/groin; active at puberty; produce smelly, thicker sweat.
What is sebum?
The oily secretion from sebaceous glands.
1st-degree
Epidermis (red, painful, sunburn)
2nd-degree
Epidermis + Dermis (blisters, painful)
3rd-degree
All 3 layers (severe damage, may be numb)
4th-degree
Deeper tissues (muscle/bone, life-threatening)
How do you identify a burn’s severity?
Based on how many skin layers are affected.
What causes ringworm?
Fungal infection (same type as athlete’s foot).
What causes impetigo?
Bacterial infection; yellow crusty sores, very contagious.
What is HSV-1?
Herpes Simplex Virus Type 1 – cold sores; ~70% of people carry it.
What is HSV-2?
Herpes Simplex Virus Type 2 – genital herpes; related to shingles.
What is HPV?
Human Papillomavirus; causes warts (genital or plantar).
What is eczema?
Inflammatory skin condition; itchy, red, scaly patches.
What is psoriasis?
Autoimmune skin disorder; scaly plaques due to fast cell turnover.
What is dermatitis?
General term for inflamed skin (can be allergic, irritant, etc.).
What is basal cell carcinoma?
Common, easily treated skin cancer; red pimple-like lesion; 99% cure rate.
What is melanoma?
Most dangerous skin cancer; dark irregular mole; spreads rapidly.
What is cyanosis?
Bluish skin due to low oxygen (deoxygenated blood).
What does “Come Let’s Get Sun Burned” stand for?
The order of epidermal layers: Corneum, Lucidum, Granulosum, Spinosum, Basale.
What happens when oxygenated blood can’t reach tissue?
Skin turns bluish (cyanosis).
What’s the relationship between the integumentary and other systems?
Works with circulatory (temperature), nervous (sensation), skeletal (vitamin D for calcium).
How can you tell if a blister contains fluid or not?
If fluid-filled = burn; if not = wart (HPV).