Unit D3- The Respiratory and Motor Systems

Breathing (ventilation)

movement of air into and out of the lungs, between the body and external environment

Respiration

All processes involved in the exchange of CO2 and O2 between a cell and the environment

respiratory system

A system of organs, functioning in the process of gas exchange between the body and the environment

Respiratory membrane

where gas exchange occurs between the air on the alveolar side and the blood on the capillary side

Pharnyx

the membrane-lined cavity behind the nose and mouth, connecting them to the esophagus.

Epiglottis

a flap of cartilage at the root of the tongue, which is depressed during swallowing to cover the opening of the windpipe.

Trachea

a large membranous tube extending from the larynx to the bronchial tubes and transports air to and from the lungs; the windpipe

Bronchi

two short branches located at the lower end of the trachea that carry air into the lungs.

Lungs

two organs enclosed by the diaphragm and rib cage responsible for respiration

Bronchioles

Airways in the lungs that lead from the bronchi to the alveoli.

Alveoli

tiny sacs of lung tissue specialized for the movement of gases between air and blood

Diaphragm

Large, flat muscle at the bottom of the chest cavity that helps with breathing, regulates pressure in chest cavity

Cilia

Hairlike structures on some cells to sweep away debris

Larynx

the hollow muscular organ forming an air passage to the lungs and holding the vocal cords; the voice box.

Pleural membrane

double-layered membrane that encloses and protects each lung, filled with fluid to reduce friction

intercostal muscles

Muscles which move the rib cage during breathing, increasing the chest's volume, and decreasing pressure

Partial pressure

Pressure exerted by a single gas in a mixture

Hemoglobin

Oxygen carrying pigment in red blood cells

Oxyhemoglobin

Hemoglobin combined with oxygen

Cardaminohemoglobin

Carbon dioxide combined with hemoglobin

Carbonic anhydrase

An enzyme present in erythrocytes that catalyzes the conversion of CO2 and H2O into carbonic acid (H2CO3).

carbonic acid - bicarbonate buffer system

chemical system that helps maintain pH homeostasis of the blood

Buffer

compound that prevents sharp, sudden changes in pH

Chemoreceptors

chemical sensors in the medulla oblongata and blood vessels that identify changing levels of oxygen and carbon dioxide

medulla oblongata

Part of the brainstem that controls vital life-sustaining functions such as heartbeat, breathing, blood pressure, and digestion, also controls bronchiole diameter

peripheral chemoreceptors

located in carotid and aortic bodies of the large arteries above the heart, respond to the O2 and CO2 content and the pH of blood, secondary regulators

Central chemoreceptors

Receptors in the medulla oblongata that detect changes in CO2 levels to help regulate ventilation rate, primary monitoring system —> more sensitive than peripheral

Kidney

Removes excess H ions from the blood

adrenal glands

a pair of endocrine glands above the kidneys that secrete hormones epinephrine/adrenaline and norepinephrine/noradrenaline)

Epinepherine (adrenaline)

increases heart and breathing rate during exercise or fight or flight

bronchitis

inflammation of the bronchial tubes, infection increases mucus production causing tissue swelling, causing difficulty in exhaling due to lower pleural pressure on inhalation

Emphysema

a condition in which the air sacs of the lungs are damaged and enlarged, and alveolar walls rupture, causing breathing problems

chronic obstructive pulmonary disease (COPD)

destructive pulmonary disorder that is a combination of chronic bronchitis and emphysema

Smooth muscle

- Involuntary

-in the lining of internal organs of the body

- mononucleated

- made of smooth myocytes

skeletal muscle

- multinucleated, attached to the bones of the skeleton & provides force to move bones

- voluntary

- made of muscle fibres

Tendon

Connects skeletal muscle to bone

antagonistic muscles

muscle pairs arranged to work against each other to move a joint, like biceps & triceps

Joints

Areas where two or more bones join together

cardiac muscle

- Involuntary

- found only in the heart

- mononucleated

- cardiomyocytes make up myocardium

Flexor

muscle that contracts to bend a limb

Extensor

The muscle that opens a joint by contracting

Sarcolemma

plasma membrane of a muscle cell, surrounds muscle fibres

- contains glycogen & myoglobin

Myofilaments

The contractile proteins, actin and myosin, of muscle cells

sliding filament theory

theory that actin filaments slide toward each other during muscle contraction, while the myosin filaments are still

Z line/disc

A dark thin protein band to which actin filaments are attached in a striated muscle fiber, marking the boundaries between adjacent sarcomeres

Sarcomere

contractile unit of a muscle fiber

striated muscle

A muscle that appears banded; aka skeletal muscle

Rigor mortis

the stiffening of the body due to muscle contraction after death

creatine phosphate

An energy storage molecule used by muscle tissue. The phosphate from this can be removed and attached to an ADP to generate ATP quickly

Latent period

Time between nerve impulse and muscle contraction

Summation

increased force of contraction by a skeletal muscle fiber when a twitch occurs before the previous twitch relaxes

Tetanus

a sustained muscular contraction resulting from a rapid series of nerve impulses

Fast Twitch muscle fibres (Type II)

A type of muscle fibre that contracts more rapidly, with more power, over a shorter period, adapted for anaerobic respiration and intense activity, has type lla and llx

Type lla muscle fiber

Fast contraction, many mitochondria, anaerobic respiration, high myoglobin content (red)

Type llx muscle fiber

Fast contraction, low mitochondria, aerobic respiration (glycolysis), low myoglobin

content (white)

slow twitch fibres (Type I)

- muscle fibre adapted for aerobic respiration, contract slowly & not very powerful, but last for long time

- high myoglobin content

The Great Oxygen Event

A time about 2.5 billion years ago, when a significant amount of oxygen appeared in the atmosphere when anaerobic cyanobacteria began producing molecular oxygen

internal respiration

Exchange of gases between cells of the body and the blood

external respiration

gas exchange between lungs and blood

Spiracles

openings in the abdomen of an insect that are used for breathing

thoracic cavity

cavity housing lungs and heart

cardiac notch

a concave space on the left lung in which the heart lies

Surfactant lipoproteins

chemical produced in the lungs to maintain the surface tension of the alveoli and keep them from collapsing

interpleural pressure

Pressure in pleural cavity - fluctuates with breathing, but always negative or lungs would collapse.

atmospheric pressure

the pressure caused by the weight of the air

bronchial tree

the branching system of bronchi and bronchioles conducting air from the windpipe into the lungs.

Surfactant

any substance that interferes with the hydrogen bonding between water molecules and reduces surface tension

cystic fibrosis

A genetic disorder that affects both the respiratory and digestive systems, causes an excessive secretion of mucus and vulnerability to infection

Lobules

small compartment associated with a segment of the lungs, located within each lobe and contain clusters of alveolar glands

Lobe

A division of a body organ (like the brain or lungs) marked off by a fissure on the surface.

subatmospheric pressure

Pressure lower than atmospheric pressure

pneumothorax

air in the pleural cavity caused by a puncture of the lung or chest wall, collapsed lung

Tidal volume

Amount of air that moves in and out of the lungs during a normal breath

Vital capacity

Amount of air that can be inhaled and exhaled in a single breath

Reserve volume

Air that can be inhaled/exhaled with max effort

residual volume

Amount of air remaining in the lungs after a forced exhalation

Respirometer

device used to measure extent of respiration

Law of Partial Pressures (Dalton's Law)

the total pressure of a mixture of gases is the sum of the partial pressures of its components, a gas in a mixture contributes the same pressure it would produce if it were the only gas in the container

Dead space

Any portion of the airway that does contain air and cannot participate in gas exchange, such as the trachea and bronchi.

Carbonic acid

a very weak acid formed in solution when carbon dioxide dissolves in water.

Bicarbonate ions

Acts as a buffer in the blood, how carbon dioxide is transported

Iron lung

machine that helped people with paralyzed diaphragms to breathe (poliovirus)

Ventilators

mechanical breathing devices

barrel chest

a condition characterized by increased chest diameter due to air trapping from small airway collapse, often seen with diseases like chronic bronchitis or emphysema

motor system

carries signals to skeletal muscles and can be voluntary or involuntary

musculoskeletal system

the system of bones and skeletal muscles that support and protect the body and permit movement

muscular tissue functions

- produces body movements

- stabilizing body position

- Storing/moving substances

- generating body heat/thermogenesis

action potential

An electrochemical impulse travelling down a nerve cell

myoglobin

An oxygen-storing, pigmented protein in muscle cells

sarcoplasmic reticulum

Organelle of the muscle fiber that stores calcium to regulate muscle contraction

t system

A set of tubules that traverse the skeletal muscle, conduct the action potential deep into the cell, and stimulate the sarcoplasmic reticulum to release calcium ions

t-tubules

tubular infoldings of the sarcolemma which penetrate through the cell and emerge on the other side

titin

a protein that positions the myosin filament to maintain equal spacing between actin filaments

zones and bands

The pattern of overlap of thick and thin filaments which cause the striated appearance of skeletal muscle.

A-band

dark area; extends length of the thick filaments

I-Band

thin filaments only, light band

H-Zone

Region of thick filaments at the center of an A band of a sarcomere only made up of myosin

M-Line

proteins in middle of sarcomere, hold the thick filaments together in the H zone

troponin

regulatory protein that binds to actin, tropomyosin, and calcium

tropomyosin

- Covers the myosin binding sites on actin filaments

- Moves and uncovers the myosin-binding site on an actin filament when troponin changes shape (Ca2+)