ib bio unit 8

Define system integration.

is the coordination and interaction of different parts of a biological system so they work together to perform life functions.

Explain why system integration is needed to perform the functions of life.

because living organisms contain many organs and systems that perform different roles. System integration ensures that these parts communicate and coordinate activities that allows processes such as movement, metabolism, homeostasis, and response to stimuli to occur efficiently.

State the two primary mechanisms by which animals integrate organ systems.

1. Nervous signaling

2. Hormonal signaling

Compare the type of signal, transmission of signal, effector response, speed and duration of response between hormonal and nervous signals.

Nervous system - electrical impulses and neurotransmitters, along neurons and across synapses, muscles or glands, very fast, and short lived

Endocrine system - hormones, through the bloodstream, targets cells with hormone receptors, slower, longer-lasting

Outline the role of blood in the transport of material and energy between organs.

Transports hormones, nutrients, oxygen and co2, waste products, heat and energy. This allows organs like the brain, muscles, and kidneys to exchange materials and maintain homeostasis

State the function of the brain.

The brain processes sensory information, integrates signals from different sources, and coordinates responses, including movement learning and memory.

List sources of information input to the brain.

• Eyes - sight

• Ears - hearing and balance

• Skin - touch, temp, and pain

• Nose - smell

• Tongue - taste

• Internal receptors - bp and oxygen levels

Outline the processes of learning and memory in the brain.

Learning occurs when neural connections between neurons strengthen. Memory includes encoding information, storing, and retrieving it later. The occurs through the changes in synaptic connections and neural pathways.

State the function of the cerebellum.

To coordinate voluntary muscle movements, maintain posture, and help control balance and precision of movement.

List organs of the central nervous system.

• Brain

• Spinal cord

Outline the two main tissues types of the central nervous system.

1. Gray matter - neuron cell bodies and synapes

2. White matter - myelinated axons

Compare and contrast conscious and unconscious processing.

Conscious processing - requires awareness, controlled by brain (Like deciding to move an arm)

Unconscious processing - no awareness, controlled mainly by spinal cord (like reflex withdrawal from pain)

State that the spinal cord can only coordinate unconscious processes.

The spinal cord coordinates unconscious reflex responses without brain involvement.

Outline the process of peristalsis of smooth muscle in the gut.

Peristalisis is the wave-like contraction of smooth muscles in the digestion tract that pushes food through the gut.

1. Circular muscles contract behind the food

2. Muscles relax ahead of the food

3. Food is pushed forward

Outline the role of the central and enteric nervous systems in movement of material into, through and out of the gut.

Cns - controls the voluntary actions like swallowing and defecation

Ens - controls the involuntary peristalisis through the digestive tract

List components of the movement of material into, through and out of the gut that are under voluntary and involuntary control.

Voluntary - swallowing, defecation

Involuntary - peristaliss through the esophagus, movement through stomach and intestines

List types of sensory receptors.

• nociceptors

• Mechanoreceptors

• Thermoreceptors

• Chemorecpetors

• Photoreceptors

• Pain receptors

Outline the function of sensory neurons.

carry impulses from receptor cells to the cns

Outline the function of motor neurons.

carry signals from the brain or spinal cord to muscles or glands that cause muscles to contract

A nerve is a bundle of nerve fibers (axons) that transmits electrical and chemical signals between different parts of the body.  Describe the structures visible in a nerve transverse cross section.

• Axons (nerve fibers)

• Mylein sheath

• Connective tissue sheath

• Blood vessels

State that nerves can contain either or both sensory and motor neurons.

• Sensory neurons

• Motor neurons

• Both (mixed neurons)

Define reflex and reflex arc.

Reflex - A rapid, automatic response to a stimulus

Reflex arc - the neural pathway that produces a reflex response

Outline the input, processing and output of the pain reflex arc, including the role of receptors, sensory neurons, interneurons, motor neurons and effectors.

1. Receptors detects pain

2. Sensory neuron sends signal to spinal cord

3. Interneuron processes signal

4. Motor neuron sends signal to muscle 

5. Effector muscle contracts and withdraws hand

Describe the mechanism by which environmental stimuli are able to activate nerve endings in the skin, including the role of receptor proteins, ions channels, and threshold potential.

Stimulus activates receptor proteins in nerve endings then opens ion channels then positive ions enter neuron which the the threshold potential reaches. The action potential is then sent to the brain

List stimuli which can trigger a pain response.

• Heat 

• Acid

• Mechanical damage

• capsaicin

Outline the flow of information during the pain response.

Stimulus → receptor → sensory neuron → spinal cord → brain → perception of pain

Outline the use of oscilloscopes in measuring membrane potential.

measure changes in membrane potential over time in neurons

Annotate an oscilloscope trace to show the resting potential, action potential (depolarization and repolarization), threshold potential and refractory period.

• Resting potential

• Threshold potential 

• Depolarization (action potential rise)

• Repolarization

• Refractory period

Deduce the number of nerve impulses per second from an oscilloscope trace.

Count the number of action potentials in one second on the trace

Outline the correlation between conduction speed of nerve impulses and axon diameter.

Large axon diameter allows faster conduction speed which is a positive correlation

Explain the difference in nerve impulse speed for myelinated and unmyelinated fibers.

Myleinated fibers conduct impulses faster due to saltatory conduction between nodes of ranvier

State the correlation between conduction speed of nerve impulses and animal size.

Conduction speed is negatively correlated with animal speed

Compare inhibitory and excitatory neurotransmitters.

Inhibitory - hyperpolarize membrane and decreases chance

Excitatory - depolarize membrane, and increases chance of action potential

Outline the inhibitory mechanism of the neurotransmitter GABA.

GABA opens chloride ion channels, causing hyperpolarization of the postsynaptic membrane

Outline the consequence of hyperpolarization by inhibitory neurotransmitters.

Membrane potential becomes more negative, making it harder to reach threshold

Describe the effects of excitatory and inhibitory neurotransmitters on the ability of a postsynaptic cell to reach its threshold potential.

• Excitatory neurotransmitters move the membrane toward the threshold

• Inhibitory neurotransmitters move it away from the threshold

Define summation.

Summation is the combined effect of multiple excitatory and inhibitory signals on a postsynaptic neuron

Define exogenous chemicals.

Exogenous chemicals are substances originating outside the body that affect biological processes

Outline the effects of neonicotinoids on synaptic transmission.

They bind to acetylcholine receptors, which causes a continuous stimulation and blocks normal synaptic transmission

Outline the effects of cocaine on synaptic transmission.

Cocaine blocks reuptake of dopamine, increasing its concentration in synapses

State that movement can occur within a body or as locomotion from one place to another.

• Movement within the body

• Locomotion from one place to another

Compare movement in motile and sessile species.

Motile - move from place to place (fish)

Sessile - fixed in place (coral)

List reasons for animal locomotion, with one example of each.

Foraging - wolves hunting prey

Escape danger - gazelle fleeing predators 

Finding mates - birds preforming mating migrations 

Migration - monarch butterflies migrating

Compare and contrast the structure and function of endoskeletons with exoskeletons.

Endoskeleton - internal skeleton, found in vertebrates, grows with organism

Exoskeleton - external skeleton, found in arthropods, must be molted

Compare the function of muscles, joints and bones to that of a lever.

Bones act as levers, joints act as fulcrums, and muscles provide the force

Define synovial joint.

a freely movable joint with a fluid-filled cavity

State the function of structures found in a synovial joint, including the bones, cartilage, synovial fluid, ligaments, muscles and tendons.

Bones - provide structure and movement 

Cartilage - reduces friction

Synovial fluid - lubricates joint

Ligaments - connect bones

Tendons - connect muscles to bone

Muscles - generate movement

Compare the articulation of hinge joints with that of a ball and socket joint.

Hinge - movement in one plane (elbow)

Ball and socket - movement in multiple planes (hip)

A muscle can only exert force when it contracts and it lengthens when it relaxes. Define antagonistic pairs in relation to muscle movement.

Antagonistic pairs are muscles that work in opposite directions to move a joint (biceps and triceps)

biceps flex

tricep relax

Outline the role of the titin protein in muscle stretching.

Titin helps sarcomeres recoil after stretching and prevents overstretching

Outline the mechanism by which the protein titin stores potential energy.

Titin is stretched like a spring when the muscle is extended, and it can store elastic potential energy that aids in the muscle's recoil when the strain is relaxed.

List three types of muscle tissue found in the human body.

• Skeletal 

• Cardiac

• smooth

Outline the relationship between skeletal muscles, muscle fibre cells and myofibrils.

Each muscle fiber in the bundles of muscle fiber cells that make up skeletal muscles has several myofibrils that aid in contraction.

Outline the structure and function of a motor unit.

Every muscle fiber in a motor unit is controlled by a single motor neuron. The linked muscle fibers contract in unison when the motor neuron transmits an input.

Outline the relationship between muscle fibers, myofibrils and sarcomeres

Muscle → muscle fibers → myofibrils → sarcomeres

Many myofibrils, which are the fundamental contractile component of muscles, are found in muscle fibers. Myofibrils are composed of repeating units known as sarcomeres.

Explain the sliding-filament mechanism of muscle contraction, including the role of actin, myosin heads, cross bridges, ATP, and the power stroke.

Actin and myosin heads attach to form cross bridges. In a power stroke, the myosin heads use the energy from ATP to drag the actin filaments toward the center of the sarcomere. The sarcomere shortens as a result of ATP allowing the myosin head to depart and restart the cycle.

Outline benefits of regulating blood supply to organs in response to changes in activity.

Controlling blood flow guarantees that the less active organs receive fewer oxygen and nutrients while the active organs receive more. It helps preserve homeostasis and increases the body's general efficiency.

Outline the cause and consequences of vasoconstriction and vasodilation.

Vasoconstriction occurs when smooth muscle in the walls of vessels contracts, narrowing the vessel and decreasing blood flow.

Increased blood flow to the tissues results from vasodilation, which occurs when the muscle relaxes and widens the vessel.

Compare blood flow to skeletal muscle, gut, brain and kidneys during sleep, vigorous physical activity and wakeful rest.

increased blood flow to the brain and organs during sleep aids in their upkeep and repair. Vigorous exercise increases blood flow to the heart and skeletal muscles while decreasing blood flow to the kidneys and intestines. We see that blood flow is divided equally among numerous organs during wakeful rest.

Compare the diameter, relative wall thickness, lumen size, number of wall layers, abundance of muscle and elastic fibers and presence of valves in arteries and veins.

Arteries - thick walls, small lumen, many muscles, no valves, carry blood from the heart

Veins - thin walls, large lumen, fewer muscles, contain valves, carry blood toward heart

State the function of arteries.

carry blood away from the heart to the body.

Describe the structures and functions of the three layers of the artery wall.

Tunica intima - a smooth inner layer that facilitates blood flow by lowering friction

Tunica media - a broad intermediate layer of elastic fiber and smooth muscle that permits blood pressure regulation and stretching

Tunica externa - Lateral outside connective tissue that offers protection and strength

Discuss how the wall thickness, lumen size, and muscle and elastic allow arteries to withstand and maintain high blood pressures.

Artieres feature modest lumens, thick walls, and a lot of smooth muscle and elastic fiber. Because of these characteristics, they can expand while the heart pumps blood and contract to keep blood pressure elevated.

Describe how the structures of capillaries are adapted to capillary function.  Include lumen diameter, branching, wall thickness, and fenestrations.

Red blood cells are kept near the wall for effective diffusion and blood flow is slowed by the narrow lumen.

Branching: Increases the surface area available for exchange by creating vast networks.

Diffusion distance is decreased by thin walls that are only one cell thick. Fenestrations: Larger molecules and fluids can pass more quickly via these tiny pores.

Compare the diameter, relative wall thickness, lumen size, number of wall layers, abundance of muscle and elastic fibers and presence of valves in arteries and veins.

Veins have a wider diameter than arteries.

Veins have thin walls, whereas arteries are thick.

Lumen size: veins are large; arteries are narrow.

Wall layers: Both have three layers, although the layers in arteries are thicker.

Elastic and muscle fibers: There are many arteries and fewer veins.

Arteries are absent, but veins are present to stop backflow.

State the function of veins.

Carry blood to the heart

Discuss how pocket valves, thin walls and skeletal muscles maintain the flow of blood through a vein.

Pocket valves: Make sure blood flows only in one direction toward the heart by preventing backflow.

Veins can be readily crushed due to their thin walls.

Skeletal muscles: Pump blood forward by contracting and squeezing veins (muscle pump).

List components of blood plasma.

Plasma proteins, nutrients, ions, salt, hormones, gases, water and waste products

Define tissue fluid.

Tissue fluid is the fluid that surrounds cells in tissues and is created when blood plasma leaks out of capillaries.

Describe the cause and effect of diffusion of blood plasma into and out of a capillary network from tissue fluid.

Tissue fluid is the fluid that surrounds cells in tissues and is created when blood plasma leaks out of capillaries.

Compare and contrast the substances found in blood plasma and tissue plasma.

Water, nutrients, and waste are present in both, but tissues have few or no proteins because particles are too large to exit capillaries, whereas plasma has more.

Outline the direction of transport of substances that are exchanged between tissue fluid and cells in the tissues.

While waste and carbon dioxide migrate from cells into tissue fluid, oxygen and nutrients travel from tissue fluid into cells.

tissue fluid → cells → tissue fluid

Outline why there is a need to drain excess tissue fluid into lymph ducts.

keeps blood pressure and volume normal while preventing edema, or the accumulation of fluid.

Outline the structure and function of lymph ducts.

vessels having thin walls and valves that transport tissue fluid, or lymph, in a single direction toward the circulation.

State how lymph is returned to the blood circulation.

Large veins close to the heart, such as the subclavian veins, are where lymph drains.

State the function of the coronary arteries.

Provide oxygen and nourishment to the heart muscle, or myocardium.

Outline the cause and consequence of a coronary occlusion.

Cause: Plaques that constrict or obstruct arteries are formed by the accumulation of fatty deposits (atherosclerosis).

Consequences: A heart attack (myocardial infarction) may result from reduced blood flow and oxygen deprivation.

Evaluate correlations between diet and lifestyle variables and risk of coronary heart disease.

Diets heavy in trans and saturated fats increase the risk of cholesterol.

Consuming a lot of salt raises blood pressure and increases danger.

Obesity, smoking, and inactivity are all closely associated with increased risk.

Risk is associated with diets high in fruits, vegetables, and unsaturated fats.

List factors that are correlated with an increased risk of coronary occlusion and heart attack.

high cholesterol

Smoking

Elevated blood pressure

Being overweight

Lack of physical activity

Stress and Diabetes

Genetics and age

Define systolic and diastolic blood pressure.

Systolic blood pressure: Pressure in arteries during ventricular contraction. 

Diastolic blood pressure: Pressure in arteries during ventricular relaxation.

interpret systolic and diastolic blood pressure measurements from data and graphs.

systolic = peak pressure; diastolic = lowest pressure between beats.

State the function of the heart and lungs/gills in the circulation of blood.

The heart circulates blood throughout the body.

Gases are exchanged in the lungs and gills (add O2, remove CO2).

Draw a diagram to illustrate the double circulation system in mammals.

Heart → lungs → heart → body → heart

Draw a diagram to illustrate the single circulation system in fish.

Heart → gills → body → heart

Explain why the mammalian heart must function as a double pump.

keeps the body's blood pressure high for effective oxygen delivery while separating oxygenated and deoxygenated blood.

Compare and contrast cardiac muscle tissue and skeletal muscle tissue.

Both have myofibrils (actin and myosin) and striations.

Heart: Involuntary, short, branched cells with one nucleus.

Long, unbranched fibers with several nuclei that are voluntary make up the skeleton.

Skeletal muscle fibers are thought of as single cells with several nuclei.

Describe how the Y-shape, intercalated discs and gap junctions of cardiac muscle cells allow for propagation of the stimulus to contract.

Branching in the shape of a Y creates a network for coordinated contraction.

Intercalated discs: Enable signal transfer and firmly connect cells.

Gap junctions allow electrical impulses to spread quickly, resulting in a synchronized heartbeat.

Define myogenic contraction.

Heart muscle (which originates within the heart) contracts in the absence of external nerve activation.

Define cardiac cycle.

One full heartbeat (ventricular systole → diastole → atrial systole).

Outline the role of the pacemaker cells in the sinoatrial node.

produces electrical impulses that start each heartbeat and determine the heart rate.

Describe the propagation of the electrical signal from the sinoatrial node through the atria and ventricles.

AV node → bundle of His → Purkinje fibers → ventricles contract after SA node → spreads throughout the atria (causing atrial contraction).

Explain the flow of blood during atrial and ventricular systole and diastole.

Blood is forced into the ventricles during atrial systole when the atria contract.

Ventricular systole: Blood is pumped to the body (aorta) and lungs (pulmonary artery) when the ventricles contract.

Diastole: Blood fills the chambers as the heart relaxes.

State that the myogenic heart rate can be adjusted by neural and endocrine feedback mechanisms.

The heart has a myogenic rhythm, meaning it generates it own heartbeat without nervous input, but the rate can be adjusted by neural and endocrine feedback mechanisms. These adjustments help maintain stable blood pressure and oxygen levels in the body..

Described the structures and functions of nervous tissue that can regulate heart rate, including the role of the medulla oblongata, sympathetic nerve, vagus nerve, baroreceptors and chemoreceptors.

The medulla oblongata in the brainstem acts as a cardiac control center. It receives sensory information and sends nerve impulses to adjust heart rate and strike volume.

Baroreceptors detect changes in blood pressure and is lcated in the carotid arteries, aortic arch. If the blood pressure rises, the barorecpetors send signals to the medulla in which then activates the vagus nerve, and the heart rate decreases. If the blood pressure falls, it signals to medulla causse sympathetic simulation, in which the heart rate increases. Chemorecptors monitor blood chemistry. They detect blood ph, oxygen concentration, and carbon dioxide concentration. It is located in carotid bodies and aortic bodies. If co2 increases, o2 decreases, or ph drops the meduclla increases heart rate and breathing rate to restore normal levels. Sympathetic nerves increase the heart activity. Its effects is to increase heart rate, stroke volume, and force of contraction. The vagus nerve decreases heart activity which decreases heart rate and reduces cardiac output.

Outline the source and effect of epinephrine on heart rate.

Epinephrine is released from the adrenal medulla. Its effect is the increases in heart rate, and force of contraction, and prepares the body for fight or flight mode.

Outline factors that will increase heart rate.

Some of the factors the increase heart rate are exercise, stress/fear, increase co2 levels, low o2 levels, low bp, epinephrine release, sympathetic nervous system activation

Outline factors that will decrease heart rate.

• Rest or sleep

• High bp

• Parasympathetic stimulation

• Relazation

• Reduced metabolic demand

Outline how the following structures allow the heart to function in delivering pressurized blood to arteries: cardiac muscle, pacemaker, atria, ventricles, atrioventricular and semilunar valves, septum and coronary vessels

Body → superior and inferior vena cava → right atrium → right av valv → right ventricle → pulmonary semilunar valve → pulmonary artery → lungs → pulmonary veins → left atrium → left av valve → left ventricle → aortic semilunar valve → aorta → body