Cell Function And Homeostasis Flashcards
Define transport across the cellular membrane
Osmosis - movement of water down the conc. gradient
Diffusion -movement of molecules from high con. To area of low conc.
Active transport - transport of substances up the conc. gradient
Examples of different cells types
Stem cells
RBC
WBC
Platelets
Nerve cells
Neuroglial cells
Muscle cells
Cartilage cells
Examples of cell actions
Reproduce
Nourishment
Movement
Excretion
Growth
Respiration
What are the 4 basic tissue types?
Connective
Epithelial
Muscle
Nervous
Function of the 3 types of muscle tissue
Skeletal - attached to bone for motion/posture
Smooth - form walls of tubes e.g airways, blood vessels, gut, bladder
Cardiac - involuntary control causing the heart to pump
Function of connective tissue
For binding, supporting, protecting (cartilage, blood, adipose, bone)
Function of epithelial tissue
Cells forming continuous sheets often lining body cavities (skin, gut lining, glands)
Function of nervous tissue
Neurone conduct electrical impulses throughout the body to control body function/movement/secretion/senses
What is apoptosis?
Cell death
What is necrosis?
Cell damage/disease
What is homeostasis?
Where the internal environment are maintained within physiological limits
What must be kept constant to protect the cell?
Chemical constitution - glucose, ions, pH
Osmotic pressie - water and soluble conc.
Temperature
O2/CO2 levels
How does homeostasis work?
Receptors - capable of detecting changes to the body
Control system - initiates corrective measures
Effectors - carries out corrective measures
What is negative and positive feedback?
Neg - reverses original stimulus - restore to normal levels
Pos - enhances original stimulus - reinforces original stimulus
What do kidney tubule cells do?
Control water and salt excretion
What do cardiac cells do?
Contract and control heart pumping, can stretch and elasticise
What does cartilage do?
Provide structural support e.g gives trachea rigidity
What do neurones do?
Conduct electrical impulses (messages)
What do sperm do?
Convey genetic material for reproduction
How does aging affect mitosis?
Slows down so cells die and re not replaced. Reduced immune cells so increased risk of infection
What does hypo and hyper mean?
Hypo = low
Hyper = high
What is the function of the nucleus?
Contains genetic material
What is the function of the membrane?
Controls passage of substances in and out of the cells
What is the function of the ribosomes?
Synthesised protein from amino acids
