Transport System Review

Smallest type of artery

Arteriole

Smallest type of vein

Venule

Smallest blood vessel and what occurs there

• Capillaries

• Exchange of Oxygen, nutrients, and waste between blood and tissue

Structures located within the veins that prevent backflow

Internal passive valves

Arteries that supply heart muscle with oxygen and nutrients

Coronary Arteries

Thin walled muscular chambers of the heart

Atria

Thick muscular walled pumps that send blood out of the heart

Ventricle

2 systems of circulation

• Systemic system (receives oxygenated blood)

• Pulmonary system (receives deoxygenated blood)

Specialized cells that initiate heart contractions and where they’re located

• Cardiac Muscle Cells

• Located in the wall of the heart

Heart tissue

Cardiac Muscle Tissue (cardiomyocytes)

6 things transported by blood

• Nutrients

• Oxygen

• Carbon Dioxide

• Hormones

• Antibodies

• Heat

4 main components of blood

• Plasma

• Red Blood Cells

• White Blood Cells

• Platelets

3 differences between the structure and functions of veins and arteries

• Veins have thin walls. arteries have thick walls

• Veins have internal valves, arteries have no internal valves

• Veins have low pressure, arteries have high pressure

Relationship between structure and function of arteries

Thick wall and fibrous outer layer maintains high pressure

Relationship between structure and function of veins

• Valves are in place to prevent back flow

• Thinner walls are necessary because there is less pressure to resist

Relationship between structure and function of capillaries

The walls are one cell thick for easy diffusion in and out

Pulmonary circulation

• Occurs on right side of heart

• Receives deoxygenated blood from systemic circulation

• Capillary bed is in lungs so blood picks up oxygen and releases carbon dioxide

Systemic circulation

• Occurs on left side of heart

• Receives oxygenated blood from pulmonary circuit

• Capillary bed is on organs/tissues so blood picks up carbon dioxide and releases oxygen

Function of valves

• Keep blood moving to heart

• Prevent backflow

Myogenic Muscle Contraction

• Initiated by cardiac muscle cells

  • Meaning it contracts without a neuron signal

• Membrane of heart muscles depolarizes when a cell contracts

  • Causes nearby cells to contract

• Keeps timing of contractions unified and useful

Carbon Dioxide regulation in the body

• Area in brainstem called Medulla Oblongata senses increase in Carbon dioxide

• SA node acts as pacemaker- receives signals from cardiovascular center in brain

• Signal causes SA node to increase heart rate to appropriate level

• After exercise carbon dioxide levels decrease

• Signal carried by vagus nerve is sent to SA node to decrease heart rate

Coronary artery purpose

• Carry oxygenated blood from aorta to all parts of heart wall

  • Oxygen and glucose

Increased risk of CHD

• Age

• Genetics

• Obesity

• Disease

• Diet

• Exercise

• Smoking

• Sex

Heart rate influenced by chemicals

• During high stress amygdala sends distress signal to hypothalamus

• Signals nerve fibers to cells in adrenal gland

  • Adrenal gland secretes adrenaline to blood stream

• SA node fires causing heart to beat faster

Receptors that detect pH

Chemoreceptors

Receptors that detect blood pressure and stretch

Baroreceptors

Fluid transportation in capillaries

• Capillaries transport blood plasma between cells and tissue

• Membrane acts as a filter for small particles to pass through

• Secrete tissue fluid

  • Contain oxygen, glucose and amino acids

  • Do NOT contain proteins

• Released due to high pressure from arteries

• Reabsorbed at low pressure by the veins

Fluid released from capillaries into cells of a tissue

Tissue Fluid

How blood returns to circulatory system after it enters the lymphatic system

• Lymphatic vessels join to form wider vessels at the end of the system

  • Merge with subclavian veins

  • Return to right side of heart by vena cava

• Lymph drained from all tissues and then returned back to blood system

Vetricles

• Chambers with strong muscular walls

• Generate high blood pressure when contracted

• Pump blood out of arteries

Atria

• Chambers with thinner muscular walls

  • Collect blood from veins and pump into ventricles

Atrioventricular Valves

• Between atria and ventricles

• Valves close to prevent backflow of blood to atria when ventricles contract

• Valves open to encourage blood flow to ventricles from atria when ventricles relax

Semilunar Valves

• Between ventricles and artery

• Valves close to prevent backflow of blood to ventricles when ventricles relax

• Valves open to encourage blood flow to arteries from ventricles when ventricles relax

Cardiac Muscles

• Muscle tissue that forms wall of ventricle and atria

• Have branched cells between plasma membrane of adjacent cells that allow electrical signals to be sent through the heart wall

• Contract through myogenic muscle contraction, NOT a motor neuron

Pacemaker

• SA node initiates each heartbeat by sending electrical signal into the atria

• Time between each signal determines the rate of heart beat

Septum

• Wall of the heart between left and right ventricles and between left and right atria

• Prevents mixing of blood from either side

Coronary Vessels

• Located in wall of heart

• Carry oxygenated blood from aorta to all parts of the heart wall

  • Supplies them with oxygen and glucose

• Also collect deoxygenated blood from heart wall and return it to right atrium

Single vs Double Circulation

Single

• Blood passes through heart once per complete circuit

• Occurs in fish

Double

• Blood passes through heart twice

• Separate circuits for oxygenated and deoxygenated blood

• Occurs in mammals and birds

Blood flow changes in Skeletal Muscle

• Physical Activity: Increased

• Wakeful Rest: Moderate

• Sleep: Reduced

Blood flow changes in Digestive System

• Physical Activity: Reduced

• Wakeful Rest: Variable

• Sleep: Variable

Blood flow changes in Kidneys

• Physical Activity: Reduced

• Wakeful Rest: Maximal

• Sleep: Reduced

Blood flow changes in the Brain:

• Physical Activity: Increased

• Wakeful Rest: Moderate

• Sleep: Increased

Ventilation vs Gas Exchange vs Cell Respiration

• Ventilation: Breathing (inhaling and exhaling)

• Gas Exchange: Oxygen and Carbon Dioxide moving between lungs and blood

• Cell Respiration: Cells use Oxygen to make ATP and release Carbon Dioxide

Ventilation system maintains concentration gradient in alevoli

• Ensures continuous fresh air

• Removes waste gas

Purpose of alevoli

• Facilitates gas exchange

  • Oxygen is taken up by blood

  • Carbon Dioxide is released into air during breathing

Type 1 vs Type 2 Pneumocytes

Type 1

• Flattened

• Majority of cells on alveolar surface area

• Carry out gas exchange

Type 2

• Rounded

• Only 5% of alveolar surface area

• Secretes fluid that coats inner surface of alveoli

Function of Pulmonary Surfactant

• Reduces surface tension in alveoli

  • Prevents collapse during exhalation

  • Facilitates lung expansion and gas exchange

Pressure during Inhalation vs Exhalation

• Inhalation: Decreases

• Exhalation: Increases

Volume during Inhalation vs Exhalation

• Inhalation: Decreases

• Exhalation: Increases

Actions of respiratory muscles while breathing during inhalation

• Muscles in abdomen wall relax

  • Pressure from diaphragm pushes it out

• External intercostal muscles contract

  • Pull ribcage out

• Internal intercostal muscles relax

Actions of respiratory muscles while breathing during exhalation

• Muscles in abdomen wall contract

  • Pressure from diaphragm pushes it upwards

• External intercostal muscles relax

• Internal Intercostal muscles contract

  • Pull ribcage inwards and downwards

Ventilation Rate changing with exercise

• Ventilation rate increases significantly

  • Needs to meet the body’s demand for oxygen

    • Removes excess Carbon dioxide

Nervous System regulation of ventilation system

• Nerves carry signal from respiratory centers of brain to the muscles used to inhale

  • Diaphragm and External Intercostal Muscles

• When lungs expand, stretch receptors detect this

  • Signals are sent to respiratory center in the brain to stop inhaling

  • Exhalation follows

  • Muscles contract

  • Cycle repeats

Spirometry

Measures lung function by assessing how much air they can breath in and out and how quickly they can do so

Ventilation Rate

Number of times air is inhaled and exhaled per minute

Tidal Volume

Volume of fresh air inhaled and stale air exhaled

Vital Capacity

Total volume of fresh air that can be exhaled after a max. inhalation, or vice versa

Inspiratory Reserve Volume

Amount of air a person can inhale forcefully after a normal tidal volume inspiration

Expiratory Reserve Volume

Amount of air a person can exhale forcefully after a normal exhalation

Cooperative binding of oxygen to hemoglobin

Oxygen Dissociation Curve

• Shows percentage oxygen saturation of hemoglobin at different oxygen concentrations

• Oxygen concentration inside alveoli is lower

Bohr Shift

• Increased respiration = increased release of carbon dioxide in blood

• Increased carbon dioxide = decreased affinity of hemoglobin for oxygen

• Increased dissociation of oxygen from hemoglobin