Lecture Exam 2 Quiz Questions Flashcards
Name the three major pigments that contribute to skin color
Melanin, Hemoglobin, and Carotene
State 3 ways that skin can contribute to thermoregulation
1) liberating sweat
2) Raising and lower hairs
3) dialating/constricting the capillaries to regulate blood flow to the surface of the body
Sebaceous glands release the whole secretory cell with the secretory product. What is the term for this method of secretion?
Holocrine
Where do you find the most sebaceous glands?
At the base of hair follicles
What protein cross-links elastin molecules together to give elastic fibers their ability to stretch and relax?
Fibrillin
What is the difference between a proteoglycan and a glycosaminoglycan?
A glycosaminoglycan is a repeating dissacharide. A proteoglycan has a core protein w/ glycosaminoglycans attached to it.
What are the main resident cells of connective tissue?
Fibroblasts
You are looking at a histological section of muscle that has striations and peripheral nuclei. What type of muscle are you viewing?
Skeletal Muscle
What type of connective tissue molecule is dermatin sulfate?
A glycosaminoglycan
What type of molecule is keratin?
a cytoskeletal protein – intermediate filament (present in skin)
What does the term hypertrophy mean?
To increase in size (hyperplasia = to increase in number)
Where owuld you find Langerhan’d cells and what do they do?
In the skin - resident dendritic cells that serve an immune function
What vitamin is activated by UV light in the skin?
Vitamin D
What does the term serous mean?
Serous membranes line one body cavities that do not open directly to the exterior – watery secretions rather than mucousy
Cutaneous membrane is another term for what organ?
Skin
What is osteoid?
unmineralized bone matrix made of calcium phosphate and matrix molecules. Mineralized matrix = calcium hydroxyapitite
Where do you find osteogenic cells?
In the periosteum and endosteum
What is it that cartilage does not repair?
Avascular, chondrogenic (cartilage producing cells) cannot be brought in after damage)
What do you call the immature cells in cartilage
Chondroblasts
How would you classify articular cartilage
Hyaline cartilage
What feature of cartilage matrix allows it to resist compressive forces?
Presence of GAGs w/ sulfated side chains that draw in water due to their negative charge (and collagen makes it strong)
What do you call the mature cells in bone?
Osteocytes
What are cannaliculi?
Channels where processes from osteocytes can meet up and form gap junctions
What do you call the concentric rings of bones that are laid down in osteons?
Lamellae
What do you call the spaces where adult bone and cartilage cells reside?
Lacunae
What do you call the “hole” in the middle of an osteon?
Central, osteonal, or haversian canal
What is present in the central canal?
Blood vessels and lymphatic vessels
Why does compact bone need to be arranged into osteons?
to allow for osteocytes to recieve nutrients and oxygen. Hard for these to diffuse through mineralized matrix. Allows for bone regeneration.
What is the generalized term for reduced bone density?
Osteopenia
Name an autoimmune disease that causes degeneration in joints? What does autoimmune mean?
Rheumatoid arthritis. Autoimmune = immune system attacking body
Name the 5 layers in the epidermis from most superficial to deepest?
Stratum corneum Stratum lucidum Stratum grandosum Stratum Spinosum Stratum Basale
Are sweat glands exocrine or endocrine? Why?
Exocrine – secrete via ducts
Do you find blood vessels in the dermis?
Yes
Do you find blood vessels in the epidermis?
No
What are the 2 layers of the dermis, form the most superficial to the deepest?
Papillary
Reticular
What cells produce pigment and where are they?
Melanocytes. Basal Layer of epidermis.
What are the most abundant cells in the epidermis?
Keratinocytes
What do we not grow taller after puberty?
our growth plates close
Why can broken bones heal?
Our bones remodel constantly
When a bone breaks, what type of tissue fills the space first?
Fibrocartilage (fibrous callus – connective tissue)
What do fractures heal faster in children?
Cells more active, more osteogenic cells, everything faster
What dietary recommendations would you give to help prevent osteoporosis?
Vitamin D and calcium taken togehter. Weight bearing exercise.
Name the cells responsible for breaking down bones
Osteoclasts
What is the developmental lineage of osteoclasts?
bone marrow =>monocyte => osteoclasts
What do osteoclasts look like?
Pacman ghosts. Multinucleate.
What is the most important horomone in maintaining calcium homeostasis?
Parathyroid horomone
What is the most important vitamin in maintaining Calcium homeostasis?
Vitamin D
State 4 organ systems important in maintaining calcium homestasis:
skeletal, endocrine, gastrointestinal, integumentary, urinary
Name some important functions of calcium in the body:
- neurotransmitter release
- membrane permeability
- muscle contraction
- enzyme activation
- intracellular second messenger
- hormone release
- blood coagulation
- bone formation
- cell motility
- cell secretion
- cellular differentiation
From what cells do osteocytes develop?
Mesenchymal stem cells => osteogenic cell => osteoblast => osteocyte
Why is compact bone organized into osteons?
to allow osteocytes to recieve adequate nutrition
Give 2 examples of bone modeling
- Shape longbones during development
- shape changes during development, e.g. tooth fracture repair
Where do you find an epiphyseal plate?
developing long bones
How do the bones fo the cranium develop?
Intramembranous ossification
Define the Method of Secretion: Merocrine Glands
or (eccrine glands) - cells excrete their substances by exocytosis; for example, pancreatic acinar cells.
Define the Method of Secretion: Apocrine Glands
a portion of the plasma membrane buds off the cell, containing the excretion.
Define the Method of Secretion: Holocrine Glands
the entire cell disintegrates to excrete its substance; for example, sebaceous glands of the skin and nose.
Define term: trabeculae
Thin columns of bone that make up spongy bone
Sudiferous (sweat) glands use what method of secretion?
Merocrine, secrete via exocytosis
What is alkaline phosphatase?
Secreted by osteoblasts, and enzyme that initiates mineralization of the osteid
