B4 - Organising Animals and Plants Flashcards
what is an aveoli
- have a large surface area for fast diffusion
- close blood supply to create a short diffusion distance
- cell wall is 1 cell thick
- has a good blood supply which maintains the concentration gradient
what are homeostatis
the process by which an organism tend to maintain stability while adjusting to conditions for survival
what is the control system
cells called receptors that detect stimuli, a coordination centre that recieves and processes information from receptors
what is the nervous system
- allows humans to respond to changes in the enviroment
- the information travels as electrical impulses
- the muscle responds to impulses by contracting
what is transpiration
the loss of water from a leaf by evaporation through the stomata
what is the transpiration stream
- water is absorbed by roots via osmosis
- up the xylem
- to the leaf
- evaporates through the stomata
what is the xylem
cells transport water and minerals up the stem from the roots and leaves
what is the pholem
cells transport glucose produced in the leaves up and down the stem to grow and storage tissues
what is translication
the movement of dissolved glucose up and down the pholem to grow parts for respiration and for storage
what is paliside mesophyll
- where photosynthesis occurs
- known as the leaf cells
what is the waxy cuticle
- reduces water loss from the leaf
what is the epidermal
contain no chloroplasts
what are guard cells
they control gas diffusion by regulating stomatal pores
what is the stomata
- allows carbon dioxide and oxygen in and out of the cell
what is the spongy mesophyll
has air spaces for lots of diffusion
in a plant what is the purpose of a leaf
to carry out photosynthesis
in a plant what is the purpose of the roots
to absorb water and nutreints from the soil, it is also used to anker the plant into the soil
in a plant what is the purpose of the stems
to transport materials to and from the leaves and the roots, to support the lead and get close to the sun
what is evaporation
The process of turning from liquid into vapour
what would increase transpiration
- lower humidity
- wind
- temperature
- higher light intensity
what are platelets
- they help form blood clots at a wound
- fragments of cells with no nuclues
what is plasma
- carrys blood cells, carbon dioxide, urea, soluble food molecues, hormones and proteins
what are white blood cells
- destroy bacteria and virus
- protects us from infection
what are red blood cells
- carry oxygen around the body
- have a biconcave shape
- contain a red protein pigment called hemoglobin
what is a capillary
- thin walls (allows diffusion on substances into and out the blood)
- out of the blood is oxygen and glucose and equals carbon dioxide
- 1 cell thick
what is a vein
- carrys blood from the organs back towards the heart
- contains deoxygenated blood
- thin muscle wall
- wide lume
- blood under low pressure
- veins contain a vaulve to stop backflow
what is an artery
- carry blood away from the heart
- carrys oxygenated blood
- thick muscle wall
- blood under high pressure
- artetys contain elastic tissue so they can strech and recoil
what is the double circutory system
- takes blood from the right side of the heart to lungs and back
- takes blood from left side of the heart to all around the body
(blood flows through the heart 2 times to complete the circuit)
what does the aorta do
carries blood to the body
what does the pulmonary artery do
carries blood to the lungs
what does the pulmonary veins do
carries blood from the lungs
what does the superior vena cava
carries blood to heart
what does the inferior vena cava do
carries blood to heart
what is the journey of the blood around the heart
- blood returns to the right atrium through the vena cava
- blood flows down into the right ventrical
- blood is pumped out of the right ventrical through the pulmonary artery, to the lungs to collect the oxygen
- oxygenated returns to the left atrium pulmonary vein
- blood flows down to the left ventrical
- left ventrical contracts to force the blood out of the aorta to the body
what is coronary heart disease
- arterys become blocked with plaque/fat, therefore less blood and oxygen is getting to the heart which means less respiration and energy
how can coronary heart disease be treated: statins
- reduce blood cholesterol levels and this slows down the rate at which fatty material is deposited in the arterys
how can coronary heart disease be treated: stents
- balloon is placed in the artery
- whilst the fat deposits narrows artery
- baloon is inflated to open blood vessel and stent
- holds artery open
how can coronary heart disease be treated: bypass
- surgery
- replacing the narrow or blocked coronary arteries
- expensive
- risks such as infection
valvue replacment: cow tissue heart valvue
- been used since 2011
- made from arterys tissue
- attached to a stent and insurted inside the valve
valvue replacement: living human heart valvue
- been used for more than 12yr
- can take a long time to find a suitable human donor
- in the opperation the chest is opened and the old valvue is removed
what is the function of a pacemaker
- regulates the heartrate
- found in the right atrium
- sends electrical impulses to make sure the heart beats in a regular rythm
what is the equation for respiration
respiration = oxyge + glucose = carbon dioxide + water
what happens when you inhale
- the diaphram contracts and moves down
- rib cage moves up and out
- volume in the chest increases
- pressure in the chest decreases
- air rushes into the lungs
what happens when you exhale
- he diaphram relaxes and moves up
- the ribcage moves down in
- volume decreases in the chest
- pressure in the chest increases
- air rushes out of the lungs
