Homeostasis and basic cell types Flashcards
Define homeostasis
The ability of physiological systems to maintain conditions within the body in a relatively constant state of equilibrium
What proportion of the body is composed of water?
60%
Describe the negative feedback loop of Thyroxine release from the thyroid gland
Hypothalamus releases TRH, TRH stimulates the anterior pituitary to release TSH, TSH stimulates the thyroid gland to release T3 and T4. High T3 and T4 concentration inhibits the release of TRH from the hypothalamus (long arm) and the release of TSH from the anterior pituitary (short arm).
What are the six different types of connective tissue?
- Embryonic
- Connective tissue proper
- Cartilage
- Bone
- Blood and Lymph
- Haemopoietic tissue
What are the four broad types of tissue?
- Connective
- Epithelial
- Muscular
- Nervous
What are the three different types of extracellular connective tissue?
- Collagen
- Elastic
- Reticular
List some of the cells present in connective tissue proper
- Mesenchymal
- Fibroblast
- Fibrocyte
- Macrophages
- Adipocytes
- Mast cells
- Plasma cells
What is the function of adipocytes?
Energy storage, insulation and protection
What do mast cells do when tissue is damaged?
Degranulate, releasing histamine (increases vascular permeability), serotonin (vasoconstrictor) and proteases
What do plasma cells produce?
Antibodies
What is fibroblasts main function?
Synthesis and secretion of collagen
What connective fibre would appear black under Verhoeff’s stain?
Elastic
What connective fibre would appear black under Reticulin stain?
Reticular
What time of gland secretes their products onto the body surface?
Exocrine glands, hence they are in contact with the surface by a system of ducts
In which cell arrangements do all cells rest on the basement membrane?
Simple and pseudostratified
