Epidermis
What are the 5 layers of the epidermis from most superficial to deepest?
Stratum corneum, stratum lucidum, stratum granulosum, stratum spinosum, stratum basale
Which layer makes up approximately 80% of the dermis?
reticular layer
What is the difference between melanin and pheomelanin?
Melanin- brown/black pigment, Pheomelanin- red/yellow
The shaft of a long bone is called the...
Diaphysis
A joint that permits no movement
Synarthrosis
Explain why the epidermis is considered avascular and describe how cells of the stratum basale receive nutrients.
No blood supply; nutrients from Dermis.
Explain how dermal papillae contribute to fingerprint formation.
Dermal papillae push upward into the epidermis, forming epidermal ridges that create fingerprints.
Why do palms and soles appear more yellow in some individuals?
Abundance of carotene
Why is resistance exercise important for maintaining the epiphyseal line during growth?
Strengthens bone growth and development
When a muscle contracts, the:
A. Origin moves toward insertion
B. Insertion moves toward origin
C. Both attachments move equally
D. Joint capsule tightens
B. Insertions moves toward origin
Outline the progression of a keratinocyte as it moves from the stratum basale to the stratum corneum.
As keratinocytes become more superficial, they slowly die.
Arrange the following structures from superficial to deep: Cutaneous plexus, Papillary layer, Reticular layer, Epidermis, Hypodermis
Epidermis, Papillary layer, Reticular layer, Cutaneous plexus, Hypodermis
Compare vellus hair and terminal hair in terms of structure and distribution.
Vellus hair- pale, fine body hair in women and children
Terminal hair- coarse, long hair found in scalp and eyebrows
Place the following bone structures from outermost to innermost: Periosteum, Compact bone, Endosteum, Spongy bone
Periosteum → Compact bone → Spongy bone → Endosteum
Most freely moveable joint
ball-and-socket
Identify the layer: A histological slide shows a single row of cuboidal cells undergoing frequent mitosis adjacent to dermal blood vessels.
Stratum basale
A surgeon makes an incision parallel to cleavage lines. Predict how this affects wound healing and explain why.
Cleavage lines heal faster and scar less because they follow natural collagen fiber orientation.
Name the 3 types of skin barriers and their functions
Chemical barrier- provides chemical barriers against UV, low pH secretes bacteria.
Physical barrier- flat, dead keratinized cells, block water and toxic substances
Biological barrier- phagocytic cells engulf invaders and digest them (immune system)
Classify the following bones:Femur, Sternum, Vertebra, Carpals
Femur- long bone
Sternum- Flat bone
Vertebra- Irregular bone
Carpals- short bones
3 factors of joint stability, from least important role to most important role
1. Shape of articular surface
2. Ligament number and location
3. muscle tone
If desmosomes in the stratum spinosum were defective, what structural changes would you expect in the epidermis?
Cells would separate
A histological section shows loose connective tissue with small blood vessels and immune cells just beneath the epidermis.
Papillary layer
A histological sample shows a gland that secretes oily material by cell rupture. Identify the gland and type of secretion.
Sebaceous gland; holocrine secretion
Describe the roles of osteogenic cells, osteoblasts, osteocytes, and osteoclasts.
Osteogenic cells- Stem cells; give rise to osteoblasts
Osteoblasts- lining for bone, actively mitotic
Osteocytes- old osteoblasts, help with reabsorption and deposition
Osteoclasts- macrophages that break down bone
Why are shoulder joints less stable but more mobile than hip joints?
More shallow joint cavity, however more surrounding muscles and ligaments