W4 Human Body Systems and Homeostatic Regulation Flashcards
What is connective tissue?
Binds cell and organs: protects support and integration
What is an epithelial cell?
Covers exterior, lines internal cavities and some glands
What is muscle tissue?
Excitable, contracts: skeletal (voluntary), smooth, cardiac
What is neural tissue?
Excitable: allows propagation of nerve impulses that communicate between different parts of body
What is the Extracellular matrix?
Material synthesised and secreted by the cells of a tissue
What do cell junctions do?
What are the 3 types?
They hold cells together
1. Gap junctions
2. Tight junctions
3. Desmosomes
What are gap junctions?
Communicating junctions, allow cells to move freely as pore in the middle
What are Tight junctions
Occluding junctions e.g. blood brain barrier
What is epithelia?
What are the names of the 3 types of layers?
What are the different types? (3)
A thin layer of matrix (basal lamina/membrane)
Single layers= 1 layer
Pseudostratified= makes it seem like 2 layers, but it is only one
Squamous, Cuboidal, Columnar
Epithelial layer referred to as a endothelium when it is re. blood vessels
What are the constituents of connective tissue?
Proteoglycans (glycoproteins)
Specialised cells
Insoluble protein fibre
Apart from blood and lymph
What is homeostasis?
Keeping the body’s environment in a state of equilibrium within normal limits.
- Oscillations around a set point
What systems does homeostasis involve?
Homeostatic control usually involves part of the endocrine system and part of the nervous system
This may be a signal from one or the other, an output from one or the other, or a mix of both to one another or to each other.
Control systems:
Local= Autocrine/paracrine
Long distance= Reflex control
What are desmosomes?
Desmosomes= Cell-cell anchoring junction. Cells need to be held together very tightly e.g. cardiac tissue
What is negative feedback?
It brings a system back to its level of normal functioning.
It maintains variation around a set point
What is positive feedback?
Give an example
Enhances or accelerates output created by an activated stimulus
- Strengthens or reinforces a change in a controlled condition
- Physiological response of effector reinforces the initial change
- Continues until interrupted by an external mechanism to the loop
Example: Birth, contractions
