Cells and Tissues Flashcards
Define the term tumour
An abnormal mass of tissue that forms when cells divide more than they should
Define the term neoplasia
An abnormal growth of cells that may develop into a tumour
Define the term malignant
Cells grow in an uncontrolled way and can have the ability to invade local tissues and spread to distant sites via the blood and lymph system
Define the term benign
Not malignant
Define the term cancer
A malignant growth or a tumour resulting from an uncontrolled division of cells
Why do HeLa cells grow so fast?
They are self sufficient in growth signals
They are insensitive to anti-growth signals
They evade apoptosis
Sustained angiogenesis
Limitless replicative potential
Tissue invasion and metastasis
How does cancer affect respiration in a cell?
The cancer favours anaerobic respiration even in the presence of oxygen
What other cells make up the tumour micro environment?
Cancer associated fibroblast
Endothelial cells
Pericytes
Cancer stem cells
Immune inflammatory cells
What are the steps in carcinogenesis?
Cell with genetic mutation
Hyperplasia
Dysplasia
In situ cancer
Invasive cancer
Name the 7 most common carcinogens
Tobacco smoking
Excess body weight
Alcohol
UV light
Diet
Cancer causing pathogens
Physical inactivity
Name the organelle…
-membrane bound
-most cells have one
-holds most of the cells genetic material
Nucleus
What in the nucleus provides structural support for the genetic material?
Nuclear lamina
What is the nucleus role in disease?
Autoantibodies in lupus attack the nucleus
Name the organelle…
-phospholipid bilayer
-contains many pores to regulate passage of molecules
Nuclear envelope
What are the inner and outer membranes of the nuclear envelope connected to?
Inner connected to lamin proteins of the nucleus
Outer connected to endoplasmic reticulum
Name the organelle…
-located inside nucleus
-Made of proteins and rDNA
-site of ribosome production
Nucleolus
What is the nucleolus role in diagnosing disease?
The appearance of the nucleolus us used to grade cancer by pathologists
Name the organelle…
-site of protein synthesis
-composed of 2 subunits
ribosome
What are the roles of each of the subunits of a ribosome?
Large subunit binds tRNA
Small subunit binds mRNA
What is the role of ribosomes in treating disease?
The fact that eukaryotic and prokaryotic ribosomes have a different structure makes them a target for antibiotics
What are the functions of free and bound ribosomes?
Free ribosomes make proteins for use in the cell
Bound ribosomes make proteins for export or for membrane surface
Name the organelle…
-Continuous with nuclear membrane and smooth endoplasmic reticulum
-site of protein synthesis
-site of protein modification
Rough endoplasmic reticulum
Name the organelle…
-originates from and stays continuous with rough endoplasmic reticulum
-no ribosomes on the surface
Smooth endoplasmic reticulum
What does the smooth endoplasmic reticulum synthesise?
Lipids
cholesterol
Steroid hormones
Phospholipids
Name the organelle…
-helps process and package proteins and lipids made by endoplasmic reticulum
Golgi apparatus
Describe protein processing and secretion
- ribosomes produce proteins on RER
- Transport vesicles containing the proteins are pinched off the RER
- Vesicles fuse with Golgi membrane and release proteins inside
- Proteins are processed and stored in Golgi
- Vesicles containing proteins are pinched off from Golgi
- Exocytosis
Name the organelle…
-degrades unneeded or damaged proteins
-very specific
-protein complex
Proteasomes
How does the proteasome degrade unneeded or damaged proteins?
Using the ubiquitin proteasome system
1. Tag protein with ubiquitin
2. Proteolysis by proteasome
Name the organelle…
-membrane bound spheres full of hydrolases
-have a low pH
-bud from Golgi
-the recycling centre
Lysosomes
What are the functions of the lysosome?
Recycling old organelles into monomers
Apoptosis
Destroy micro organisms so abundant in macrophages
Name the organelle…
-membrane bound
-full of enzymes (oxidases)
-originate from endoplasmic reticulum
Peroxisomes
What are the functions of peroxisomes?
Scavenge free radicals
Lipid metabolism
What three components make up the cytoskeleton?
Microtubules
Intermediate filaments
Microfilaments
Which part of the cytoskeleton has the function…
-maintaining cell shape
-cell motility
-chromosome movements in cell division
-organelle movements
Microtubules
Which part of the cytoskeleton has the function…
-maintaining cell shape
-anchorage of nucleus and other organelles
-formation of nuclear lamina
Intermediate filaments
Which part of the cytoskeleton has the function…
-maintaining cell shape
-muscle contraction
-cell motility
-cell division
-changes in cell shape
Microfilaments
Name the organelle…
-double membrane
-matrix and cristae
-site of aerobic respiration
Mitochondria
What is the role of mitochondria in disease?
Mutations in the mitochondrial genes cause rare but devastating mitochondrial disorders
What are the features of mitochondrial diseases?
Occur when mutations are inherited in mitochondrial DNA
Rare and severe
Can only be inherited from the mother
What are the end products of aerobic respiration?
Water
CO2
36 ATP
What are the end products of anaerobic respiration?
Lactic acid
2 ATP
What is the difference between cytosol and cytoplasm?
Cytosol is just the fluid filling the cell and embedding the other organelles
Cytoplasm is the cytosol + all organelles - nucleus
What is the protoplasm?
Cytosol + all organelles (including nucleus)
What do you call a group of cells that have similar structure and that function together as a unit?
Tissue
What do you call a collection of tissues that together perform a certain specific function?
Organelle
What do you call the embryological tissue from which all types of supporting elements are derived?
Mesenchyme
What do you call the cells and tissues that support and give structure to organs, glands and other tissues in the body?
Stroma
What is the stroma made up of?
Connective tissue
Blood vessels
Lymphatic vessels
Nerves
What is the difference between the parenchyma and the stroma?
In tissues and organs, parenchyma is the functionally specialised cells and stroma are the less specialised supporting tissue
What do haematoxylin and eosin stain?
Haematoxylin stains acidic structures purple/blue (e.g. nucleus)
Eosin stains basic structures red/pink (e.g. cytoplasmic proteins)
What is the epithelia?
Diverse group of tissues that include surface epithelia and solid organs
what is surface epithelia>
Surface epithelia cover or line all body surfaces, cavities and tubes
What is the function of epithelia?
Form a protective barrier
Regulate exchange of molecules
Synthesis and secretion of glandular products
What are the features of epithelia?
Tightly packed cells
Polarity
Anchored to basement membrane
Lack blood cells
Supported by laminate propia (connective tissue)
High ability for regeneration
Connected by intercellular junctions which maintain integrity and allow communication between cells
What types of cell to cell adhesion are there?
Tight junction
Adherens junction
Desmosome
Gap junction
What types of cell to matrix adhesion are there?
Focal adhesion
Hemidesmosome
What is bullous pemphigold and what causes it?
Autoimmune blistering skin disorder
Patients present with blisters and itching
Autoantibodies cause release of cytokines which produce an inflammatory reaction that destroys the hemidesmosomes
Causes subepidermal blisters
What is pemphigus vulgaris and what causes it?
Autoimmune condition
Caused by autoantibodies against epidermal antigens
Patients present with thick crusty or blistered skin
What does stratified and pseudostratified mean when it comes to describing epithelium?
Stratifies is when there are multiple layers of cells
Pseudostratified means there’s a single layer but the cells are all different heights giving a stratifies appearance
What are some site specific adaptations of the skin?
Stratified squamous epithelium
Provides protection against abrasions and water loss
Epithelium is keratinised (cells lose their nucleus and cytoplasm for keratin making them waterproof)
What are some site specific adaptations of the GI tract?
Ciliated columnar epithelium
Cilia on surface
What is a site specific adaptations of the urinary tract?
Specialised stratified lining that is an impermeable barrier to water and ions
What is a site specific adaptations of the bladder wall?
Able to stretch to increase volume when the bladder fills with urine
Known as the transitional epithelium
Name and describe this mesenchymal tissue
(Insert fatty tissue pic)
Fatty tissue
Composed of adipocytes
Name and describe this mesenchymal tissue
(Insert bone tissue pic)
Three cell types
-osteoblasts
-osteoclasts
-osteocytes
Types of bones
-woven
-lamellar
-cortical
-trabecular
Name and describe this mesenchymal tissue
(Insert tendon pic)
Tendon
Dense connective tissue structure
Made of collagen fibres, elastin, glycoproteins, proteoglycans and fibroblast cells
Name and describe this mesenchymal tissue
(Insert cartilage picture)
Cartilage
Composed mostly of collagen
Types include…
- Hyaline cartilage
- Fibrocartilage
- Elastic cartilage
Name and describe this mesenchymal tissue
(Insert muscle pic)
Muscle
Types include
- skeletal
- cardiac
- smooth
Marfan syndrome affects mesenchymal tissue. In what way does it do this?
Genetic disorder
Affects connective tissue
Leads to abnormalities in the skeleton, heart and eyes
Name three diseases arising from abnormal mesenchymal tissues
Marfan syndrome (connective tissue)
Lipoma (benign tumour of fatty tissue causing soft masses under the skin)
Angiosarcoma (aggressive cancer that forms from lining of blood/lymph vessels)
What type of adult cell am I describing?
- very high turnover
- bowel, skin, bone marrow
Labile cells
What type of adult cell am I describing?
- good ability to regenerate but lower turnover
- hepatocytes, bone
Stable cells
What type of adult cell am I describing?
- once it is gone, its gone and cell loss is replaced by scarring
- nerve cells, cardiac muscle cells, skeletal muscle cells
Permanent
What is proliferation?
Growth, repair of damage, replacing tired cells
(Basically just cells dividing)
Describe the steps in the cell cycle
G1 - cell growth
S phase - DNA synthesis
G2 - More growth
Mitosis - cell divides its DNA and cytoplasm
How many chromosomes are present at the end of interphase?
46
What’s the process by which 50 million sperm are made per day?
Spermatogenesis
What is different about female meiosis?
Meiosis 2 doesn’t start until triggered by entry of sperm
What is apoptosis?
Programmed cell death that doesn’t release harmful products or cause inflammation
Can be triggered by intracellular and extracellular signals
What is necrosis?
Unintended cell death as a response to injury
What makes necrosis so bad?
Spillage of cell contents leads to activation of inflammatory pathways
What are the 4 symptoms of necrosis and what do they mean?
Rubor = redness
Calor = heat
Tumor = swelling
Dolor = pain
What are the 5 types of necrosis?
Coagulative
Liquefactive
Caseous
Gangrene
Fat
What is coagulative necrosis?
Caused by Ischaemia (lack of blood supply)
Leads to lack of oxygen to tissues
Can cause big heart attacks of even rupture the walls of the heart
What is liquefactive necrosis?
When the dying cells have little supporting tissue so liquefy leaving cavities
What is caseous necrosis?
Dead tissue is walled off
Cells are broken down but not eaten by phagocytes so clump together
What is gangrene necrosis?
Tissues rot
They go black from iron deposition from degrading haemoglobin
What is fat necrosis?
Secondary damage to fat from internal or external cause
Why are these cells called HeLa cells?
INSERT PIC
Due to the case of Henrietta Lacks
What is the difference between a somatic and germline mutation?
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