Movement of Substances, Circulatory System, Hormones, Homeostasis, Reproduction Flashcards
Definition of diffusion
The movement of particles from an area of high concentration to an area of low concentration until equilibrium.
Definition of osmosis
The movement of particles from an area of high water potential to an area of low water potential through a partially permeable membrane.
Active transport definition.
The movement of particles against the concentration gradient requiring energy.
What effect does increasing SA: VOL ratio have on rate of movement?
Increases
What effect does increasing distance have on rate of movement?
Decreases rate.
What effect does increasing temperature have on the rate of movement?
Increases the rate.
What effect does increasing the concentration gradient have on rate of movement for diffusion and osmosis?
Increases rate of movement.
What effect does increasing concentration gradient have on rate of active transport?
Decreases rate.
4 components of blood.
- Red blood cells
- White blood cells
- Plasma
- Platelets
Function of red blood cells
To transport oxygen around the body using haemoglobin
Adaptations of red blood cells
Biconcave
No nucleus
Haemoglobin
Function of phagocytes
Phagocytosis (enclosing, ingesting and digesting pathogens with enzymes)
Function of lymphocytes
To produce and release antibodies
Definition of antibodies.
Soluble proteins
4 things that antibodies do:
Neutralise toxins produced by pathogens
Cause bacteria to burst open and die
Label the pathogen so it can be found by phagocytes
Stick pathogens together in clumps
Function of plasma
To transport: Hormones Nutrients Urea CO2 Heat energy
Function of platelets
Involved in blood clotting to prevent loss of blood (specifically erythrocytes) and infections.
Equation for how platelets create a protein mesh.
Fibrinogen (soluble plasma protein) —> fibrin (insoluble)
Definition of a pathogen
A disease causing cell. Can be fungi, bacteria, protoctist and viruses.
Explain how vaccination reduces danger of a specific pathogen.
- injects inactive pathogen cells into the bloodstream.
- allows lymphocytes to create the specific antibodies needed to combat the pathogen
- once the pathogens have been eliminated, a few lymphocytes remain in the bloodstream as memory cells.
- if the pathogen were to return, the memory cells would be able to produce antibodies sooner, faster and in greater quantity.
3 differences between structures of artistries and veins
- Arteries have thicker, more elastic walls
- Arteries do not have valves
- Arteries have smaller lumens.
Function of capillaries.
To take oxygen and nutrients to cells in organs and muscles as well as to take waste products away.
Adaptations of capillaries.
- small
- one cell thick walls
Explain why heart rate increases during exercise
- an increased amount of energy is needed for muscles to contract
- more blood carrying oxygen and glucose needs to be pumped by the heart to the muscles for aerobic respiration
- heart rate increases
Explain what happens when someone has Coronary Heart Disease.
The coronary artery, which supplies blood to the heart for aerobic respiration becomes blocked (by a buildup of fat) and so the heart may run short of O2 and not be able to contract.
Factors to decrease risk of CHD:
- regular exercise
- eating fewer fatty foods
- smoking (increases blood pressure)
- hereditary
- high cholesterol levels
Definition of homeostasis
The maintenance of a constant/stable environment
What three things does a coordinated response require?
Stimulus (the change in environment)
Receptor (the part of the body that detects the change)
Effector (the organ/cell/tissue that produces a response)
3 things that happen when body is too hot
Sweating, cools down the skin.
Vasodilation, allows heat to radiate from blood to surroundings.
Hair erector muscles relax.
3 things that happen when body is too cold.
Vasoconstriction, prevents heat from radiating to surroundings
Hair erector muscles contract, creating insulation layer
Muscles shiver, forcing body to produce (heat) energy
Source, role and effect of ADH
Source: pituitary gland
Role: to maintain constant body water levels
Effect: prevents water from being excreted when body is dehydrated by making collecting duct more permeable so it can be reabsorbed
Source, role and effect of FSH
Source: pituitary gland
Role: menstrual cycle
Effect: causes the maturation of an egg in the ovaries, stimulates production of oestrogen.
Source, role and effect of LH
Source: pituitary gland
Role: menstrual cycle
Effect: inhibits production of oestrogen, causes an egg to be released by ovaries, stimulates production of progesterone.
Source, role and effect of adrenaline
Source: adrenal gland
Role: to prepare body for fight/flight response,p
Effect: increases heart rate and breathing rate, initiates conversion of glycogen to glucose in the liver, blood is diverted from digesting system to muscles in the limbs
Source, role and effect of insulin
Source: Pancreas
Role: to bring blood glucose levels back to normal
Effect: stimulates liver to convert glucose into glycogen, which is the storage form of glucose.
Source, role and effect of testosterone
Source: testes
Role: to control the development of male secondary characteristics
Effect: stimulates sperm production
Source, role and effect of progesterone
Source: ovaries
Role: menstrual cycle
Effect: maintains the uterus lining, inhibits production of LH
Source, role and effect of oestrogen
Source: ovaries
Role: controls the development of female secondary sexual characteristics
Effect: inhibits production of FSH, causes the uterus lining to thicken and grow
Describe the role of the placenta nun the nutrition of the developing embryo.
- allows substances to diffuse from the mother’s blood to the foetus and opposite
- mother —> foetus antibodies, water, amino acids, fatty acids, glycerol, glucose
- foetus —> mother carbon dioxide, urea.
Role of the amniotic sac in protecting the embryo.
Protects the embryo by cushioning impacts
Contains amniotic fluid (made up mostly of foetal urine)
