Learning Objectives Week 1-2 Flashcards
Describe the main difference between apoptosis and necrosis
Apoptosis is a programmed and controlled cell death and does not kill neighbouring cells. Necrosis is uncontrolled cell death triggered by trauma.
Define infarction
Tissue death (necrosis) caused by inadequate blood supply
Define an epithelial cell and its function
Cells that form organ, skin, and blood vessels linings. Their functions are protection, secretion, absorption, and sensory reception
Define connective tissue and its primary function
Type of tissue that provides support, structure, and binding for other tissues in the body. Function is to connect, anchor and cushion organs, as well as providing structural support and transport nutrients and waste
What is meant by labile, stable and permanent cells, with one example each
Labile cells: constantly dividing e.g. epithelial cells in the skin and mucous membranes
Stable cells: usually resting but can divide to repair tissue when needed. E.g. smooth muscle cells
Permanent cells: unable to undergo division e.g. neurons
What determines whether a stimulus causes atrophy or infarction
the severity and duration of the blood supply interruption. Atrophy occurs with mild or chronic interruption, infarction results from severe or sudden blockages
What affect does ageing have on cells and organs?
Ageing causes cellular damage, decreased function, and reduced tissue regeneration capacity in organs
Define neoplasia
Think: benign or malignant
Abnormal and uncontrolled growth of cells, forming a mass or tumour
Tumour
Abnormal mass of tissue resulting from neoplasia, which can be either benign or malignant
Malignant
Tumours that are cancerous and have the potential to invade nearby tissues and metastasise, resulting from neoplasia
Dysplasia
Abnormal development or growth of cells, which may indicate pre-cancerous changes
-In-situ
Cancer that is confined to its original sites without invading nearby tissues
Metastasis/metastasise
The spread of cancer cells from their original sites to other parts of the body
What is the most common cancer type in adults and why?
Carcinomas, which arise from epithelial cells, which cover the body’s entire surface and organs. higher likelihood of neoplasia
What are the differences between benign and malignant tumours?
Benign tumours grow slowly, are localised, and do not invade surrounding tissues
Malignant tumours grow rapidly, invade nearby tissues and can metastasise
List the 3 main routes of metastasis and common sites affected
Lymphatic spread: cancer cells travel through lymphatic vessels and metastasise to lymph nodes
Hematogenous spread: cancer cells enter bloodstream and spread to distant organs (e.g. liver, bones, brain)
Direct seeding: cancer cells spread to nearby organs or tissues by direct implanting (e.g. abdominal cancers)
Hyperaemia
Increased blood flow to a specific area to meet the metabolic needs of its tissues
Oedema
Accumulation of fluid in tissues, categorised as exudate (high protein) or transudate (low protein)
Effusion
Abnormal accumulation of fluid in body cavities
Organisation
Process where inflammatory exudate is replaced by granulation (new connective tissue) tissue, leading to scar formation
What form of cell death causes an inflammatory response
Necrosis
What are the 3 features of acute inflammation?
Redness (rubor), warmth, swelling (tumor)
What are the consequences of healing through organisation?
May result in loss of tissue function of fibrosis (excessive scar formation)
What are the 3 causes of chronic inflammation?
Persistent infections, autoimmune reactions, prolonged exposure to irritants or allergens
Define the 3 general features of chronic inflammation
Infiltration of immune cells, tissue destruction, attempts at repair (fibrosis)
What is meant by sterile and non sterile sites in the human body? Give examples
Parts that are exposed to the external environment and may contain microorganisms. Sterile sites lack residential micro-organisms, while non sterile sites harbour normal flora
Sterile: blood, brain
Non-sterile: skin, GIT upper respiratory
Difference between the innate and adaptive systems
Innate immunity is non specific and immediate, while adaptive immunity is specific and develops over time (vaccinations)
Describe autoimmune response
Immune system attacks body’s own tissues
Describe hypersensitivity reaponse
Exaggerated immune response to harmless substances
Define immune-compromised
Individuals with weakened immune systems, such as those with HIV/AIDS or undergoing immunosuppressive therapy
Hyperplasia, hypertrophy, atrophy and metaplasia are examples of a what adaptation?
Cellular adaptation
