PCS Unit 1 Questions Flashcards
What are osteoclasts?
They are large, multinucleated cells that make and secrete digestive enzymes that break up or dissolve bone tissue.
They collapse bone.
What are osteoblasts?
They make bone in response to growth factors and mechanical stress on the bone.
They build bone.
What is the periosteum?
Loose connective tissue sheath that surrounds the outer layer of bone.
What is the difference between periosteum and endosteum?
Periosteum forms the outer fibrous connective tissue layer of bone while endosteum forms the inner layer lining the cavity of the bone.
What are keratinocytes?
They are skin cells. The most common type of cell in the epidermis (outer layer of the skin)
What is the basal lamina? How is it different to lamina propria?
It forms part of the basement membrane which attaches to epithelial cells
Lamina propria is the layer below the basement membrane
What does Myosin Phosphatase do in Smooth Muscle?
It enables cross bridges to detach
What is the difference between collagen type 1 and type 3?
Collagen 1 has high tensile strength (can undergo a lot of force before breaking and provides lots of support) where as collagen 3 produces an elastic network that stores kinetic energy as an elastic rebound.
Type 1 is found in skin, bones, tendons and ligaments
Type 3 is found in muscles, arteries and organs
What is the name of cell-cell anchoring junctions found between epithelial cells of the small intestine?
Adherens Junctions
What is covalent modification?
This is where proteins are modified by the breaking or formation of covalent bonds to affect their function (e.g. Phosphorylation of enzymes where the phosphoric group is attached by a covalent bond)
What type of connective tissue is found in tendons and ligaments?
Dense regular connective tissue as it contains lots of fibres so is very strong. (It is regular as it is strong in one direction)
What type of transport is performed by ATP synthase?
Passive transport (H+ moves down an electrochemical gradient)
Why would you use a PET scan?
To detect cancer.
Patient takes positron emitting radioactive tracers such as FDG. As cancer cells often have higher metabolic activity, PET scans can highlight areas with higher metabolic activity which helps access metabolic activity and to determine if a cancer is malignant or benign.
