3. organisms P2

motile organisms

organisms that have adaptations allowing movement within their habitat

sessile organisms

organisms that cannot move from one place to another

venus flytrap example

• carnivorous plant native to subtropical wetlands

• live in soil deficient of minerals specifically nitrogen

• the plants trap is a pair of leaves with short but sturdy trigger hairs

• within a second of the hairs being triggered, the leaves close around the pray animal, to prevent it from escaping

Brown throated three toed sloth

a motile but very slow organism

they are tree dwelling and herbivorous

have three toes that in combo with their bone structure are adapted to hang from trees

what is each muscle made of

made up of thousands of muscle fibres because of their elongated shape (multinucleate and they represent several cells that have merged together

each muscle fibre is composed of…

many protein filaments called myofibrils that run parallel to each other

what are placed next to myofibrils?

contracting units called sarcomeres

sarcomeres attachment to each other

hey are all attached to each other end to end, wen one contracts the sarcomeres in that same muscle contract.

what happens when a sarcomere contracts

the myosin remain stationary and the two sides of the actin move towards the centre of the sarcomere.

the myosin have moveable heads that interact with the actin to accomplish this using the energy of ATP

why do they move?

myosin heads are activated by splitting ATP, causing a change in position of the heads.

myosin heads are attracted to and attach to exposed binding sites of actin to form cross bridges

as myosin forms cross bridges ADP is released and the myosin bends due to loss of energy. The bending is towards the centre of the sarcomere and the actin is moved inwards.

myosin binds to ATP, allowing detachment of the myosin heads from the actin attachment sites.

tendons

connective tissue attaches 2 bones at each end of the muscle

anchor

one bone acts as an immoveable anchor (origin) and the other (insertion) moves asa result of the contraction

antagonistic

a muscle can only exert a force when it contracts so once a bone has been moved, the opposite movement requires another different muscle.

The two muscles which are said to be antagonistic to each other.

titin

muscles use a force to help with relaxation, as a result of the spring like action of titin protein.

immense proteins that has multiple folds that allow it to act as a spring

holds myosin fibres in place in the sarcomere and prevents muscle fibres from overstretches.

what happens in sarcomere contraction in relation to titin

when sarcomere shorten durinhg contraction, the two sides of each sarcomere move towards the centre

this creates a spring like tension in titin that is released when the muscle relaxes

this allows each sarcomere of the muscle to undergo a contraction once again .

how are skeletal muscle contractions controlled

under the nervous system

neuromuscular junctions

every movement made requires many electrical impulses originating in your brain and terminating at synapses called…

motor neurons

these junctions are a type of synapse where a chemical message is sent into the muscle tissue to stimulate a contraction

motor unit

each muscle is able to contract with varying intensity depending on how many of the total muscle fibres within the muscle receive a nervous system impulse to contract. each single motor neuron has a set number of muscle fibres that it controls and its called a motor unit.

vertebrate animals…

have endoskeletons made of bones

what is an endoskeleton

muscles are attached to the bones at various points to allow the movements

arthopods like insects…

have exoskeletons made of a substance called chitin

what is an exoskeleton

the skeleton is on the outside of the animals body and the muscle attachment points are on the inside of the hollow skeletons.

anthropods and leverage

because they have both jointed legs and body parts, they are capable of having amazing range of motion

synovial joints

occur when two bones need to move against each other and are notable for wide ange of motions that they allow

pelvis and femur

bones forming the ball and socket joint of teh hip

cartilage

a smooth protective connective tissue that lines both the pelvis and femur within the hip joint

synovial fluid

lubricating fluid within the hip joint that reduces friction

ligaments

tough connective tissue that holds the bones of the hip joint in place

tendons

connective tissue that connects each of the muscle of the hip joint to its appropriate bones

muscles

muscle tissues that contract and relax to enable movement of the femur within the socket of the pelvis.

intercostal muscles

lie in between each pair of ribs and use the ribs as their origin and insertion points

each set works to change the shape of the entire ribcage

location of intercostal muscles

when looking from the outside, you would first see teh external ICM and beneath this set would be the Internal ICM

what happens when the external ICM contract

the ribcage is pulled upwards and out, the antagonistic internal ICM move the ribcage down and inwards

the movement of the ribcage and different orientations of the muslce fibers permit a stretching of the muscle layer that is not contracted.

this stretches the titin fibre in each sarcomere of this muscle layer, creating potential energy which will be used for the next contraction.

need for locomotion (foraging for food)

honey bees, flying from flower to flower to collect nectar

need for locomotion (searching for mate)

loggerhead sea turtle, both males and females swim back to the beach where they were hatched to mate and lay eggs.

need for locomotion (migration)

butterflies migrate to start the breeding season all over again and in order to do that they must migrate.

adaptations for swimming

• have streamlined body

• no body hair to reduce drag

• have a tail adapted to form a fluke which allows up and down movement

• have an airway blowhole located in the top surface of the head to exchange air without leaving the water too far.

where do capillaries receive their blood from?

from the smallest of arteries called arterioles

where does a capillary bed drain its blood?

into the smallest of veins called venules

surface area of capillary bed

the total surface area is very large due to the extensive branching of capillary beds so that no cell in the body is far from the capillaries

what are fenestrations?

small slits or openings that allow large molecules to enter or exit the blood and allow increased movement

how are capillaries adapted to their function?

• small inside diameter

• being thin walled

• being permeable

• large surface area

• fenestrations

arteries

receive blood from the heart and take blood to the capillary bed

veins

receive blood from the capillary bed and takes blood to the heart

pressure of blood in arteries

because arteries receive blood directly from the heart, it isunder relatively high pressure, so they are lined with a thick layer of smooth muscles and elastic fibres

pressure of blood in the veins

receive low pressure blood, they are relatively thin walled with large lumen to carry slow-moving blood.

artery structure

• layered with smooth muscle

• the smooth muscles change the diameter of the arteries to regulate blood pressure

what happens when blood flows through arteries?

• the muscular and elastic tissues are stretched and allow the vessel to handle the high pressure

• after the blood has passed the elastic fibres recoil and provide further pressure, propelling the blood forwards.

carotid artery abd teh radial atery

at the side of the trachea

side of the wrist with the palm of your hand facing upwards, 2cm from the base of your thumb.

adaptations of veins

veins have thin walls and larger internal diameter

internal valves to aid unidirectional flow of the slow-moving blood in the veins (prevent backflow)

the thin walls of veins are easily compressed by surrounding muscles (one of the may reasons to remain active) to push the blood along

why does the heart need nutrients?

its a very thick and active muscle and like any other muscles requires nutrients and oxygen to be healthy adn active

coronary artery

the arteries which supply blood to cardiac muscles

plaque

overtime, a personmay develop a build-up of cholesterol in the lumen of arteries

occlusion

this build up of plaque restricts blood flow which is called…

what does occlusion lead to

if a occluded artery is the coronary artery, it may result in a heart attack because the cardiac muscle in one or more areas is deprived of oxygen.

a plant relies on transpiration because…

the tension force created by transpiration is used to bring up dissolved minerals up from roots.

what does the loss of water cause?

it causes water to be pulled through the cell walls of nearby xylem tissue by capillary action, this creates negative pressure at the upper end of each xylem tube.

what does negative pressure do?

results in the movement of water up the xylem and the entire column of water moves up because of cohesion, and this ensures a continuous movement of water.

structure of xylem tubes

cylinder shaped plant cells stacked on each other to make a long tube

when they die they leave their thick cylinder shaped cell walls

the dead xylem tubes have cell walls fortified with lignin for strength.

lignin

a durable, waterproof polymer that serves as a "backbone" for plants, providing structure and support.

what does the lignin provide…

provides resistance to collapse of the tubes because of the tension created by transpiration

epidermis

prevents water loss and provides protection from microorganisms

cortex

an unspecialised cell layer that sometimes stores food reserves

xylem

transport tubes which carry water and minerals up from roots

phloem

transports carbs, from leaves to other parts of the plant

vascular bundle

contains multiple vessels of both xylem and phloem

tissue fluid

in order for cells to chemically exchange substances with blood, there has to be fluid between the cells and the blood.

chemical makeup of tissue fluid and plasma

• very similar due to the largely unregulated pathway of substances through very porous capillary membranes and gaps under arteriole pressure

why are they similar?

red blood cells do not exit the capillaries thus remain in the blood stream, because they are too large. some white blood cells are able to squeeze through capillaries into tissue fluid.

plasma membranes..

often use active transport mechanisms to regulate the presence of various ions

fish heart

have a 2 chambered heart, one to receive and the other to pump out blood

when blood is pumped out, it is sent to the gills for oxygen and carbon dioxide to exchange

the reoxygenated blood is collected from the gills capillaries and sent to capillary beds in body tissues

the deoxygenated blood is then returned to the heart to be pumped to the gills again.

limitation of single circulation

the loss of blood pressure when the blood is within the capillaries of the gills.

mammalian circulation

use a double circulation pattern via a heart which has four chambers

pulmonary circulation

one side of the heart is used to pump teh blood to capillaries in the lungs for reoxygenation

systematic circulation

the blood is returned to the other side of the heart to be pumped out to capillaries in body tissues, to supply oxygen to where its needed

How is blood pressure restored

the additional trip to the heart

right side of the heart…

sends blood to and from the lung capillaries in a route called the pulmonary circulation

left side of the heart

sends blood to and from body tissues via systematic circulation

why does the heart have specific adaptations

in order to ensure the atria contract simultaneously

cardiac muscle

highly vascular tissue making up the heart muscle (especially near the ventricles)

the muscle is thickest near the ventricles because it pumps out blood to all locations in the body.

a pacemaker

known as the sinotrial node

an area of specialised cells in the right atrium which generate a spontaneous electrical pulse to start each heart beat.

Atria

thin muscular chambers of the heart designed to receive low pressure blood from the capillaries of the lungs or body tissues by the way of large veins entering the heart

ventricles

thick muscular chamber of the heart designed to receive low pressure blood from the capillaries of the lungs or body tissues by way of large veins entering the heart

atrioventricular valves

valves located between atria and ventricles that close each heart cycle to prevent backflow

semilunar valves

valves which close after the surge of blood into the pulmonary artery or aorta, to prevent backflow

septum

wall of muscular fibrous tissue that separates the right side of the heart form the left

coronary vessels

blood vessels that provide oxygenated blood to. the heart muscle

systole

when a chamber of the heart contracts there is an increase in pressure of the blood within the chamber, and the blood leaves the chamber through any available opening

diastole

when a chamber is not undergoing systole the cardiac muscle of the chamber is relaxed

how do the artria and ventricle function

both atria contract at the same time, therefor both undergo systole simultaneously. both ventricles also undergo systole at the same time just a fraction of a second after the atria systole.

action potential from SA node

spreads almost instantly and result in the thinwalled atria undergoing systole

ECG

a graph plotted in real time, with electrical activity (from SA and AV nodes) plotted on the y axis and time on the x

direction of movement of sap

from a source to a sink

source: net sugar producer

sink: plant organ that uses or stores sugar

cellular structure of phloem is based on…

two types of cells that pair together as a functional unit

sieve tube

individual phloem sieve tubes are connected to each other by porous sieve plates to form sieve tube elements

sieve tube elements

do not contain a nucleus because they are designed to be nearly empty in order to serve as vessels carrying fluid.

translocation

the movement of sap within the sieve tube elements

phloem is made up of

mainly sieve tube elements and companion cells

sieve tube elements..

line up end-to-end to form a continuous tube through which phloem sap flows