Cell Function And Homeostasis LO

Question 1

Different types of cells and their functions

Answer 1

Connective tissue: most abundant cells - binding supporting, protecting
Epithelial tissue: continuous sheets - lines body cavities
Nervous tissue: conduct electrical impulses throughout the body controlling function/movement/secretion/senses
Muscle tissue: skeletal muscle under voluntary control, attachment to bone for motion/posture

Question 2

Explain relationship between cells, tissues and organs

Answer 2

Groups of similar cells = tissues
Groups of similar tissues = organ
Collection of related organs = organ system

Question 3

Explain how organs work together in major body systems

Answer 3

The function of an organ system depend on the integrated activity of organs

Question 4

Outline apoptosis and programmed cell death

Answer 4

1) cells shrinks, chromatin condenses
2) membrane starts blebbing, organelles disintegrate
3) nucleus + organelles collapse, membrane continues to bleb
4) apoptotic bodies form
5) macrophages phagocytise apoptotic bodies
NO INFLAMMATION

Question 5

Define homeostasis

Answer 5

The tendency towards a relatively stable environment

Question 6

Indentify control systems

Answer 6

Change stimulus > receptor > control centre > effector > corrective response
Blood pressure - baroreceptor in artery walls
Blood glucose - glucose receptors in pancreas islet cells

Question 7

What is positive and negative feedback?

Answer 7

Positive - a change that triggers a response causing more change in the same direction
Negative - a change which reverse the original change back to a certain point