- keratin intermediate filaments that make up tonofibrils
- found in stratum spinosum
- found in the stratum spinosum.
- These cells act as macrophages and engulf and digest pathogens.
- found in the stratum granulosum. Contain glycolipids
- which make the epidermis water-proof.
- found in the stratum granulosum.
- contain the tough, insoluble protein, keratin, which makes the epidermis tough and abrasive-resistant.
the structural units of chromatin, packages chromatin
What is a nucleotide made up of?
- · A pentose sugar (deoxyribose or
· A nitrogen-containing base – A, G, C, T, or U
· A phosphate group
the other DNA strand not used in transcription.
- simple squamous epithelium
- lines blood vessels, circulatory system
- serous membrane
- Main purpose is to create a lubricating fluid that is released between layers.
- not found in humans, secretory product
- accumulates on the apical side of the cell’s cytoplasm.
- That part of the cytoplasm then pinches off, releasing the product into the lumen of the gland.
- cell secretes products via exocytosis
- eccrine sweat glands (regular sweat)
- apocrine sweat glands (yellowish, puberty)
- The cell accumulates secretory product within
- its cytoplasm.
- The cell then dies and its products are released into the lumen.
- A new layer of cells are ready to take its place.
- sebaceous oil glands
touch receptors found in the papillary layer
- increase friction and gripping power
- we leave behind fingerprints because a film of sweat is left behind by the ridges.
What tissue is the reticular layer made of?
What is housed here?
- dense irregular connective tissue
- touch receptors for deep pressure (Pacinian corpuscles)
- stretch marks
- found at the junction of the epidermis and dermis.
- acts as light touch receptors
What are functions of the skin?
- protection from infection
- protection from UV radiation (melanocytes)
- temperature regulation
- metabolism (synthesis of vitamin D)
- receives stimuli from the environment
- deep pressure receptors
- found in reticular layer
6 functions of epithelium
- sensory reception
finder hair of children and adult females
the coarser, longer hair of the eyebrows, armpits, and pubic region.
Sections of Hair
- In the middle is the medulla, which has large cells and air spaces. Only part of the hair that has soft keratin.
- Outside that is the cortex, which has several layers of flattened cells.
- The outermost cuticle is formed from a single layer of cells that overlap one another like shingles on a roof.
- Hair conditioners smooth out the rough surface of the cuticle.
- The cuticle tends to wear away at
- the tip of the hair shaft, allowing the fibrils in the cortex and medulla to frizz out, resulting in split ends.
First Degree Burn
- only the epidermis is affected
- heals in 2-3 days
Second Degree Burns
- injures the epidermis and the upper region of the dermis.
- will see blisters.
- will heal in 3-4 weeks if infection is prevented.
Third Degree Burn
- All layers of the skin are affected.
- The burned spot will not be painful.
- Skin grafting is necessary.
- Most dangerous because of the patient’s aversion to infection and fluid loss.
Basal Cell Carcinoma
- occurs in the stratum basale
- most common type of skin cancer and least dangerous
Squamous Cell Carcinoma
- involves keratinocytes in the stratum spinosum.
- grows rapidly, second most common type
- proliferation of the melanocytes
- most malignant, highly metastatic and resistant to chemotherapy
What is compact bone composed of?
- shaped like a sesame seed
- a short bone that is formed in a tendon
- ex: patella
- the shaft (middle) of the long bone.
- Made of a thick collar of compact bone that surrounds a medullary cavity.
- ends of the long bones
- have spongy bone inside
- covers the entire bone
- outer layer is the fibrous layer (dense irregular CT)
- inner layer is osteogenic layer, has osteoblasts, osteoclasts, and osteogenic cells.
- the inner membrane separating the compact bone from the spongy bone.
- Contains osteoblasts and osteoclasts.
- tiny canals that connect the lacunae to each other and to the central canal.
- Allows for transfer of substances from one osteocyte to the next (via gap junctions).
the concentric tubes in the osteon
forms the skull bones and the clavicles
- forms all the bones in the body except the clavicles and skull bones
- starts out as hyaline cartilage.
Parathyroid Hormone (PTH)
- released under hypocalcemic conditions
- calcium in blood is too low
- stimulates the osteoclasts to release calcium from the bones
Longitudinal Bone Growth
- 4 processes
- 1. Growth zone - chondroblasts create hyaline cartilage
- 2. Hypertrophic zone - old chondrocytes start to deteriorate
- 3. Calcification zone - calcium phosphate salts move towards the epiphyseal plate and chondrocytes will die
- 4. Ossification zone - osteoblasts move into the deteriorating hyaline cartilage stalactites. secrete new bone tissue on the diaphyseal face of the epiphyseal plate.
Function of bone remodeling
maintains levels of calcium homeostasis
- released under hypercalcemic conditions
- levels of calcium in blood are too high
- stimulates osteoblasts to produce bone tissue
slightly moveable joints
freely moveable joints
Fibrous Joints (3)
sutures, syndesmoses, gomphoses
- elongated bursae that wrap around tendons to reduce friction.
- Present in joints that are used very often.
- flattened fibrous bags of synovial fluid associated with synovial joint.
- Also reduces friction.
discs of fibrocartilage that improve the fit at a synovial joint. Reduces friction as the joint moves.
- movement along one or two planes
- intertarsal joints
- vertebrae between C1 and C2.
- lets you rotate on a plane
- allows us to motion yes.
- example is wrist joint.
only saddle joint in body is the metacarpal joint of thumb.
What are the characteristics of a synovial joint?
- A synovial joint has a two-layered articular capsule, which has a fibrous capsule on the outer membrane and the synovial membrane internally.
- Inside the articular capsule is the joint cavity, which contains synovial fluid.