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79 Cards in this Set
- Front
- Back
3 functions of skin |
Primary function - radiation, chemicals, microorganisms Physiological function - sweat, vit D Network of nerve cells that detects + relays changes in the environment (heat, pain, itch) |
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What are keratinocytes held together by? |
Desmosomes |
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What cell types does the dermo-epidermal junction consist of? |
Keratinocytes and fibroblasts |
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What junction types is present in stratum granulosum? |
Tight junctions |
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What junction type is rich in stratum basale layer? |
Adherents junction |
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What cell type is rich in stratum spinosum layer? |
Desmosomes |
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What cell types are present in the basement membrane of skin? |
Hemidesmosomes and focal adhesions |
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What are the 3 cell types of the epidermis? |
Keratinocytes Langerhans cells Melanocytes |
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What are considered to be the dendritic cells of the epidermis? |
Melanocytes and langerhans cells |
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Where are melanocytes found? |
The basal layer of the epidermis |
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Describe how the concentration of melanocytes varies in different parts of the body |
Highest concentration in face and male genitalia, lowest on trunk |
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Difference in the melanocytes present in those with dark skin |
They are larger and have more processes |
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Where do langerhans cells originate? |
Bone marrow |
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Function of langerhans cells? |
Thy acquire antigens in peripheral tissues, transport them to regional lymph nodes, present them to naive T cells, thus initiating an adaptive immune response |
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Where are langerhans cells present? |
In all layers of the epidermis except the stratum corneum |
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Describe how the numbers of langerhans cells may be affected |
Numbers not affected by Uv but increase in allergic reactions |
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Describe the function of melanocytes |
Melanin is transferred from melanocytes to keratinocytes via their dendritic processes |
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Describe eccrine glands |
Temperature control glands, excrete sweat, present everywhere on human skin apart from nail beds and lips, most abundant on palms, soles and axillae |
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Describe apocrine glands |
Scent glands, role unclear, present in axillae and genitals |
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Describe sebaceous glands |
Present everywhere except palms and soles, greatly enlarge at puberty in response to androgens (acne), main function is to provide lipids which lubricate hair shaft |
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Describe composition of the dermis |
Connective tissue: collagen fibres, elastic fibres, fibroblasts and 'ground substance' |
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What are the damaging effects of ultraviolet on skin |
Direct cellular damage e.g. Photo aging and DNA damage, and alterations in immunological function |
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What causes the development of melanoma and non melanoma skin cancers |
The mutation of P53 tumour suppressor genes cause by DNA damage |
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What cells work together to protect cells from uv DNA damage? |
Keratinocytes and melanocytes |
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Chronic uv exposure in humans leads to... |
Loss of skin elasticity Abnormal pigmentation Haemorrhage of blood vessels Wrinkles and premature ageing |
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Erosion = ? |
Only epidermis lost |
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Ulceration = ? |
Structures deep to the epidermis |
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Partial thickness injury = ? |
Epidermis and varying parts of dermis. Adnexal structures serve as a reservoir of epithelial cells to repopulate the wound and cells from the wound edge |
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Full thickness wound = ? |
Epidermis and all of dermis and deeper structures. Wound edge cells only |
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Describe the factors hat affect wound healing |
Size of wound Blood supply to area Age and health of patient Nutritional status of patient Drugs the patient may be taking Presence of foreign bodies and microoragnsims Variety of systemic diseases: diabetes mellitus |
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Justice = ? |
Fairness |
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Respect for autonomy = ? |
Respect for self-determination |
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Beneficence = ? |
Patients best interests |
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Non maleficience |
Balance of risks/harm vs benefits |
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Why 3 mechanisms allow proteins to get into organelles? |
Nuclear pores - for nuclear proteins Via membrane translocation - for ER and motochondrial proteins Vesicular transport (vesicles) - for proteins going beyond ER |
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What is the definition of a cell? |
The basic unit from which living organisms are made, consisting of an aqueous solution of organic molecules enclosed by a membrane |
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Why cytoskeleton system supports the inner membrane of a cell (above nuclear lamina) and helps to position nuclear pores? |
Intermediate filaments Lamins |
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What are the features of the plasma membrane? |
Phospholipid bilayer Cholesterol Lipid rafts Carbohydrates Proteins |
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What's substances are rich in the lipid rafts of the plasma membrane of a cell? |
They are cholesterol rich Enriched in proteins to form 'signalling platforms' |
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What is the main role of mitochondria? |
ATP production |
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What are he 4 compartments of a mitochondria? |
Outer membrane: selectively permeable (e.g. Pyruvate) Inner membrane (folded into numerous Cristae): electron transport chain Matrix: enzymes for citric acid/ TCA cycle Intermembrane space: important in electron transport chain and other enzymatic reactions |
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What is the main role of mitochondria? |
ATP production |
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What are he 4 compartments of a mitochondria? |
Outer membrane: selectively permeable (e.g. Pyruvate) Inner membrane (folded into numerous Cristae): electron transport chain Matrix: enzymes for citric acid/ TCA cycle Intermembrane space: important in electron transport chain and other enzymatic reactions |
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What is the function of tight junction? |
Seal (prevent leakage between cells) Epithelial cell polarity (apical and basolateral domains) |
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What are the 4 compartments of a mitochondria? |
Outer membrane: selectively permeable (e.g. Pyruvate) Inner membrane (folded into numerous Cristae): electron transport chain Matrix: enzymes for citric acid/ TCA cycle Intermembrane space: important in electron transport chain and other enzymatic reactions |
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What are the different factors of tight junction? |
Function: Seal (prevent leakage between cells) Epithelial cell polarity (apical and basolateral domains), selective permeability Components: Claudins Cytoskeleton: actin Example: epidermis
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What are the different factors of GAP junctions? |
Function: metabolic and electrical coupling Components: Connexins Cytoskeleton: N/A Example: cardiac tissue |
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Describe different factors of Adherens junctions |
Function: tissue integrity, contractility, motility Components: cadherens Cytoskeleton: Actin Example: morphogenesis |
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Describe the different factors of desmosomes |
Function: strong adhesion, resist mechanical stress Components: desmosomes cadherins Cytoskeleton: IF Example: epidermis, myocardium |
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What are the 4 compartments of a mitochondria? |
Outer membrane: selectively permeable (e.g. Pyruvate) Inner membrane (folded into numerous Cristae): electron transport chain Matrix: enzymes for citric acid/ TCA cycle Intermembrane space: important in electron transport chain and other enzymatic reactions |
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What are the different factors of tight junction? |
Function: Seal (prevent leakage between cells) Epithelial cell polarity (apical and basolateral domains), selective permeability Components: Claudins Cytoskeleton: actin Example: epidermis
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What are the different factors of GAP junctions? |
Function: metabolic and electrical coupling Components: Connexins Cytoskeleton: N/A Example: cardiac tissue |
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Describe different factors of Adherens junctions |
Function: tissue integrity, contractility, motility Components: cadherens Cytoskeleton: Actin Example: morphogenesis |
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Describe the different factors of desmosomes |
Function: strong adhesion, resist mechanical stress Components: desmosomes cadherins Cytoskeleton: IF Example: epidermis, myocardium |
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Describe the different factors of focal adhesion |
function: cell anchorage, mechanical and biochemical signalling Components: integrins Cytoskeleton: actin Example: cell migration |
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What is the main role of mitochondria? |
ATP production |
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What are the 4 compartments of a mitochondria? |
Outer membrane: selectively permeable (e.g. Pyruvate) Inner membrane (folded into numerous Cristae): electron transport chain Matrix: enzymes for citric acid/ TCA cycle Intermembrane space: important in electron transport chain and other enzymatic reactions |
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What are the different factors of tight junction? |
Function: Seal (prevent leakage between cells) Epithelial cell polarity (apical and basolateral domains), selective permeability Components: Claudins Cytoskeleton: actin Example: epidermis
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What are the different factors of GAP junctions? |
Function: metabolic and electrical coupling Components: Connexins Cytoskeleton: N/A Example: cardiac tissue |
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Describe different factors of Adherens junctions |
Function: tissue integrity, contractility, motility Components: cadherens Cytoskeleton: Actin Example: morphogenesis |
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Describe the different factors of desmosomes |
Function: strong adhesion, resist mechanical stress Components: desmosomes cadherins Cytoskeleton: IF Example: epidermis, myocardium |
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Describe the different factors of focal adhesion |
function: cell anchorage, mechanical and biochemical signalling Components: integrins Cytoskeleton: actin Example: cell migration |
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Describe the different factors of hemidesmosomes |
Function: cell anchorage Components: integrins Cytoskeleton: IF Example: dermal-epidermal junction |
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An example of a cell type that would have an extensive Rough ER |
Plasma cells and hepatocytes |
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What cytoskeletal component is found in cilia? |
Microtubules |
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What cytoskeletal component is found in cochlear hair cells? |
Stereocilia Actin |
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What cytoskeletal component is found in the apical surface of absorptive cells lining the gut? |
Microvilli Actin |
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What cytoskeletal component is found in the apical surface of absorptive cells lining the gut? |
Microvilli Actin |
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Which cytoskeletal system participates in cell membrane extension and motility? |
Lamellipodia and filopodia Actin |
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Defects in what are associated with kartageners syndrome? |
Cilia and flagella |
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Defects in what are associated with kartageners syndrome? |
Cilia and flagella |
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A disorder in which cell junction results in deafness or Vohwinkel syndrome? |
GAP junctions |
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Defects in what are associated with kartageners syndrome? |
Cilia and flagella |
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A disorder in which cell junction results in deafness or Vohwinkel syndrome? |
GAP junctions |
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Which vesicles is involved in oxidative reactions? |
Peroxisomes |
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Which cell junctionnis formed between cells and the ECM? |
Focal adhesions |
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What is the lifespan of a red blood cell? |
Around 110 days |
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What is the transcriptome? |
The subset of genes that are actually transcribed |
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How can microorganisms be broadly classified? |
Prokaryotes Eukaryotes |