MOD 7 Flashcards
Name 3 factors that influence the size of a cell population
- cell proliferation
- cell differentiation
- death by apoptosis
What are 3 mechanisms and 3 things cells use for communication
Things: hormones, local hormones (growth factors), stroma-stroma contact
Mechanisms: autocrine, paracrine, endocrine
How do Stem cells divide and why is this method beneficial
They divide asymmetrically to replenish differentiated cells whilst keeping one stem cell able to continually fuel the stem cell population
Name two examples of labile tissue and its relevance to the cell cycle
Always in the cell cycle
a) epidermal hyperplasia from basal layer
b) Bone marrow - hyperplasia
Name two examples of stable tissue and its relevance to the cell cycle
In G0 but can be induced back into the cell cycle
a) osteoblasts
b) hepatocytes
Name three examples of permanent tissue and its relevance to the cell cycle
Does not enter the cell cycle, is only capable of hypertrophy
a) brain neurons
b) cardiac muscle
c) skeletal muscle
What are the 5 cellular adaptations?
- regeneration
- hypertrophy
- hyperplasia
- atrophy
- metaplasia
What is regeneration and reconstitution?
Regeneration is restoring the cell # back to normal, reconstitution is replacing an entire organ/body part which humans have little capacity to do - only our capillaries are capable of this.
What 3 conditions influence the formation of resolution?
- if injurious stimuli is removed
- non-extensive tissue damage
- if it’s in labile or stable tissues
What 3 conditions influence the formation of scarring?
- if injurious stimuli persists
- if tissue damage is extensive
- if it occurs in permanent tissues
What is hyperplasia, and what does it put you at risk for?
Cell proliferation, increases the chance of a mutation
2 Pathological hyperplasia examples (not cancer)
a) The goitre:
- TSI mimics TSH stimulating the thyroid to overwork and produce more T3 and T4.
- An iodine deficiency: no T3 and T4 being produces stimulates the thyroid to try harder and make more (no negative feedback)
b) Eczema: proliferation of the dermal layer
2 Physiological hyperplasia examples
a) endometrium under influence of estrogen
b) Bone marrow produces erythrocytes in response to hypoxia
What is Hypertrophy?
What are the conditions in which it is mainly seen
Increase in cell size
Done in permanent tissues and likely alongside hyperplasia in labile and stable tissues
2 Physiological examples of hypertrophy
a) skeletal muscle at the gym
b) During pregnancy your uterus undergoes hyperplasia and hypertrophy