2- Growth disorders, neoplasms Flashcards
(46 cards)
What are the 8 normal processes of growth and differentiation
Environmental influence
Feedback mechanisms
Hormone regulation
Genetic control
Tissue growth
Organogenesis
Cell division
Cell differentiation
Environmental influence and feedback mechanisms
Evironmental Influence: External factors such as nutrition, physical activity, and exposure to stimuli can impact growth and differentiation.
Feedback Mechanisms: Feedback loops help maintain homeostasis and regulate growth processes in response to internal and external cues.
Hormone regulation and genetic control function
Hormonal Regulation: Hormones play a crucial role in coordinating growth and differentiation processes.
Genetic Control: Gene expression and regulation guide cell differentiation and tissue development.
What is the difference bewteen tissue growth and organogenesis
Tissue Growth: Cells proliferate and organize to form tissues with distinct structures and functions.
Organogenesis: Different tissues come together to form complex organs during development.
Cell division and cell differentiation
Differentiation- cell develops a specialised function or morphology which distinguishes it from its parent cell and takes on specific functions as tissues and organs develop.
Cell Division: Cells divide and replicate to increase their numbers during growth.
What are the two systemic and local abnormalities of growth
H H
hyperplasia and hypotrophy
What is carcinogenesis
Carcinogenesis, also called oncogenesis or tumorigenesis, is the formation of a cancer, whereby normal cells are transformed into cancer cells.
Characterized by; changes at the cellular, genetic, and epigenetic levels and abnormal cell division.
What is differentiation
cell develops a specialised function or morphology which distinguishes it from its parent cell.
Endocrine
factors in postnatal growth
GH,TH, I, IGFS, SS, C, PTH
Postnatal growth is governed by multiple endocrine factors:
Growth Hormone (GH): Secreted by the pituitary gland, it stimulates growth in tissues and bones and promotes the production of insulin-like growth factors (IGFs).
Thyroid Hormones (TH): Produced by the thyroid gland, these hormones are crucial for overall growth and development, including the maturation of the nervous system and bone growth.
Insulin: Produced by the pancreas, it has anabolic effects on muscle and tissue growth, apart from its role in glucose metabolism.
Insulin-like Growth Factors (IGFs): Mostly produced in the liver in response to GH; they are significant mediators of growth in cells and bones.
Sex Steroids: Including testosterone and estrogen, these hormones are responsible for the growth spurt during puberty and the development of secondary sexual characteristics.
Cortisol: A steroid hormone from the adrenal cortex that in high levels can impair growth but is needed in normal levels for tissue maturation and metabolism.
Parathyroid Hormone (PTH) and Vitamin D: These regulate calcium and phosphate metabolism, which is vital for bone growth and maintenance.
The interplay between these hormones ensures proper postnatal growth and development. Imbalances can lead to growth disorders, requiring careful medical attention.
Endocrine factors in foetal growth
-Small parents, racial origin and lower foetal insulin or occasionally insulin receptors
- if increased growth foetal hyperinsulinaemia (Maternal diabetes)
What are the major causes of endocrine abnormality
u/a, o/a, malfunction
1) Underproduction of a certain hormone
2) Overproduction of a certain hormone
3) A malfunction in the production line of a hormone or in its ability to function correctly.
What is morphopigenesis
a complex process of embryological development
Formation of shape and organisation of body organs
Involves growth, differentiation, and relative movement of groups of cells
Programmed cell death (apoptosis) removes unwanted cells
What is apoptosis and what is it controlled and stimulated by
Is a form of programmed cell death.
It is controlled by P53 and other parts. Also, its stimulated by growth factors needed for body processes
What is growth a balance between
cell division and apoptosis
What develops last in morphopigenesis
Head is one of the last things to develop in morphogenesis
Foetal pancreas and then thyroid develops
- placenta does it is the source for nutrients and removing waste products. Fetal pancreas and thyroid then develop
What is hyperplasia and what process is it controlled by
Increase in cell number by mitosis
Hypertrophy is an increase of____ without _____________
cell size
cell division
What is atrophy
decrease in
Decrease in size or wasting away of a body part or tissue. also : arrested development or loss of a part or organ incidental to the normal development or life of an animal or plant. atrophy.
Example of abnormal tissue growth
Benign neoplasms (tumour)
Types:
Benign bone tumors (osteomas).
Brain tumors such as meningiomas and schwannomas.
Gland tumors such as pituitary adenomas.
Lymphatic tumors such as angiomas.
Benign soft tissue tumors such as lipomas.
Uterine fibroids
How is cell differentiation controlled
Embryonic differentiation of cells is controlled by gene expression, systemic hormones, position within the foetus, local growth factors and matrix proteins.
Maintenance of differentiated state depends upon the persistence of some of these factors.
Differentiation and morphogenesis can be disrupted by environmental factors (e.g. teratogens)
Control by the genome
what can a single master gene do
A single master gene can switch other genes on and off
example; dolly the sheep- a sheep cloned in America
What is aptosis controlled and stimulated by
Aptosis controlled by P53 and other parts . Stimulated by growth factors needed fir body processes
What is post natal growth controlled by
G
GH-IGF-1 axis
What is pre natal growth controlled by
MN and HS
Maternal nutritional and hormonal state
