Cellular Signaling and Extracellular Matrix Quiz

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Questions and Answers

Which type of signaling involves a cell releasing a substance that affects its own activity?

Endocrine signaling
Paracrine signaling
Autocrine signaling (correct)
Synaptic signaling

Which type of collagen is primarily found in the basement membrane?

Collagen type II
Collagen type I
Collagen type IV (correct)
Collagen type III

What is the main function of proteoglycans and hyaluronan in the extracellular matrix?

Providing tensile strength and recoil
Connecting matrix elements to each other and to cells
Providing hydration and swelling pressure (correct)
Acting as signaling molecules

Which of the following statements about growth factors is TRUE?

They can promote cell migration and differentiation. (B) Signup and view all the answers

How do growth factors promote entry into the cell cycle?

By promoting the synthesis of cellular proteins. (B) Signup and view all the answers

Which of these is NOT true about the extracellular matrix (ECM)?

The ECM is primarily composed of water and lipids. (B) Signup and view all the answers

Which type of signaling is involved when hormones travel through the bloodstream to reach their target cells?

Endocrine signaling (A) Signup and view all the answers

Which of the following is NOT a role of the ECM during wound healing?

Directly killing bacteria (B) Signup and view all the answers

Which of the following growth factors is NOT released during the hemostasis phase of wound healing?

Vascular endothelial growth factor (VEGF) (B) Signup and view all the answers

What is the primary function of polymorphonuclear leukocytes (PMNs) during the inflammation phase of wound healing?

Release of pro-inflammatory cytokines (A) Signup and view all the answers

Which of the following cells are responsible for the removal of dead PMNs from the wound site via apoptosis?

Macrophages (C) Signup and view all the answers

Which of the following is a defining characteristic of the proliferation phase of wound healing?

Synthesis of new extracellular matrix components (C) Signup and view all the answers

What is the primary function of fibroblasts during the proliferation phase of wound healing?

Synthesis of collagen and other ECM components (B) Signup and view all the answers

Which of the following events is NOT characteristic of the remodeling and maturation phase of wound healing?

Increased vascularization (A) Signup and view all the answers

Which of the following factors can potentially lead to delayed wound healing?

Presence of chronic infection (D) Signup and view all the answers

Which of the following is NOT directly involved in re-epithelialization?

Collagen deposition (B) Signup and view all the answers

What is the primary function of angiogenesis in wound healing?

To provide nutrients and oxygen to the growing tissue (D) Signup and view all the answers

Which of the following factors is NOT primarily responsible for initiating endothelial cell migration during angiogenesis?

Collagen synthesis (C) Signup and view all the answers

What is the significance of the leakiness of newly formed blood vessels in wound healing?

It contributes to the edematous appearance of the healing tissue (B) Signup and view all the answers

Which of the following is NOT a characteristic of granulation tissue?

Dense collagen fibers (A) Signup and view all the answers

What is the primary role of fibroblasts in wound healing?

To synthesize collagen and other extracellular matrix components (A) Signup and view all the answers

After wound healing is complete, what happens to the many nonfunctional blood vessels that were formed during angiogenesis?

They are degraded, leaving few vessels in the mature scar (D) Signup and view all the answers

Which of the following best describes the relationship between the wound healing processes of re-epithelialization and angiogenesis?

Angiogenesis occurs before re-epithelialization (C) Signup and view all the answers

What is the primary function of fibroblasts in the wound healing process?

Fibroblasts are responsible for the synthesis and deposition of the extracellular matrix, including collagen and elastin. (D) Signup and view all the answers

Why is the extracellular matrix (ECM) important for the maintenance of blood vessels?

The ECM provides structural support for blood vessels and aids in the regulation of growth factors essential for their integrity. (C) Signup and view all the answers

Which of the following is NOT a key cytokine involved in the remodeling phase of wound healing?

Fibroblast Growth Factor (FGF) (C) Signup and view all the answers

How does oxygen contribute to the formation of mature collagen in wound healing?

Oxygen is essential for the hydroxylation of proline and lysine residues in collagen, which is critical for proper bonding and structure. (C) Signup and view all the answers

What is the main reason for the reduction in cellularity at the wound site during the remodeling phase?

The cells are undergoing apoptosis, a programmed cell death process, as they are no longer needed. (C) Signup and view all the answers

What distinguishes healing by first intention from healing by second intention?

Healing by first intention is characterized by a clean wound with minimal tissue loss, while second intention involves a larger, more complex wound with significant tissue loss. (D) Signup and view all the answers

What is the primary role of contractile fibroblasts (myofibroblasts) during wound healing?

Myofibroblasts contribute to the contraction of the wound, drawing the edges closer together. (C) Signup and view all the answers

What are hypertrophic scars and keloids primarily a result of?

An excessive production of collagen fibers during the remodeling phase. (C) Signup and view all the answers

Which of these cell types can regenerate after injury, but only to a limited extent?

Stable cells (B) Signup and view all the answers

Which of the following is NOT a defining characteristic of labile cells?

They are limited in their ability to regenerate in response to injury. (B) Signup and view all the answers

Permanent cells, unlike labile and stable cells, are characterized by their inability to:

Proliferate (B) Signup and view all the answers

Which of the following is an example of a tissue that primarily relies on repair rather than regeneration after injury?

Cardiac muscle (C) Signup and view all the answers

Which of the following BEST describes the process by which damaged tissue is restored to its original state?

Regeneration, involving the proliferation of uninjured cells. (C) Signup and view all the answers

What is the main reason why labile cells can regenerate more easily than stable cells?

Labile cells contain a pool of stem cells. (D) Signup and view all the answers

Which of the following statements is TRUE about the healing process?

Healing always involves both regeneration and repair. (D) Signup and view all the answers

Which of the following is a defining characteristic of the repair process?

Formation of scar tissue as a result of connective tissue deposition. (C) Signup and view all the answers

Which of the following conditions is NOT a systemic factor that can impede wound healing?

Excessive UV light exposure (D) Signup and view all the answers

Which of the following best describes the difference between a hypertrophic scar and a keloid?

Hypertrophic scars remain within the wound boundaries, while keloids extend beyond the original wound. (C) Signup and view all the answers

What is the underlying cause of dehiscence, a complication of wound healing?

Increased pressure on the wound site, often due to abdominal distention. (C) Signup and view all the answers

Which of the following is a potential consequence of chronic wound infection?

Osteomyelitis (A) Signup and view all the answers

Which of the following is a specific example of a neoplasia arising from a wound?

Marjolin's ulcer (D) Signup and view all the answers

Which of the following factors directly influences the effectiveness of wound healing by promoting granulation tissue formation?

UV light exposure (C) Signup and view all the answers

Which of the following scenarios is LEAST likely to contribute to wound dehiscence?

A patient with a healthy weight undergoing a routine skin graft procedure. (D) Signup and view all the answers

Which statement MOST accurately reflects the impact of nutrition on wound healing?

A balanced diet with sufficient protein, vitamin C, zinc, and magnesium promotes efficient wound healing. (D) Signup and view all the answers

Drugs that block Nicotinic Ach Recpetors and other examples which block Nicotinic Ach receptors

Curare - Muscle relaxant blocks Nicotinic receptors .. also snake venom causes blocking of them causing muscle spasms/paralysis Signup and view all the answers

Drugs blocking muscarnic Ach receptors

ATROPINE blocks muscarnic receptors this drug is used to dilate pupils and reduce secretions Signup and view all the answers

Clinical significance of Acetylcholine

<ol> <li>Myasthenia Gravis - Abs attack Nicotinic receptors leading to muscle weakness 2. Alzheimer’s- Neurodegenerative disease where there is decreased levels of ACH, 3. Botulinum Toxin- inhibition of Ach release leading to excessive Ach accumulation and muscle spasms . 4. Nerve Gas and organophosphate- inhibhotion of AchE leading to excessive Ach . 5. Nicotine - stimulates Nicotinic receptors leading to addiction</li> </ol> Signup and view all the answers

What are the 4 bioamine neurotransmitters

Histamine, serotonin , dopamine , norepinephrine (C) Signup and view all the answers

What do amphetamines , Antidepressents , cocaine , Resperine do to norepinepphrines

<ol> <li>Amphitamines they enhance release of norepinephrine 2. Antidepressents and cocaine they stop reuptake of norepinephrines leading to more norepinephrine in blood 3. Resperine - depletes norepinephrines</li> </ol> Signup and view all the answers

Dopamine drugs relevance

L-Dopa - levodopa - precursor used to treat Parkinson’s , 2. Amphetamines- Increase dopamine release 3. Cocaine - blocks reuptake leading to addictioon Signup and view all the answers

SEROTONON Drugs

<ol> <li>LSD- Alters serotonin 2. MDMA-increases serotonin release “ecstasy” . 3. SSR’s - Used to treat depresssion</li> </ol> Signup and view all the answers

Histamine drugs

<ol> <li>Cimetidine - blocks histamine H2 receptors reducing stomach acid production</li> </ol> Signup and view all the answers

Flashcards

Healing

The body's response to injury for restoring normal structure and function.

Regeneration

Process by which some tissues replace damaged components and return to a normal state.