Biology 1144 Exam 4

ventilation

the process of bringing oxygenated water or air into contact with a gas-exchange organ

cutaneous respiration

organisms can exchange gases through a moist, thin and permeable skin.

ex: amphibians (do not have lungs they rely on for bulk of gas exchange)

organisms that do not have a specialized circulatory system

invertebrates that are only a few cell layers thick allow oxygen and carbon dioxide to diffuse directly across the body surface

ex: cnidarians and Platyhelminthes

gills

feathery structures that are capable of extracting oxygen from either air or water

common in many invertebrates and fish

external gills

external to the body surface

- have to move these gills to ensure adequate gas exchange

- easily damaged

internal gills

located within the animal body

- protected by operculum

- countercurrent exchange

- flow through system.

countercurrent exchange

oxygen diffused from water into capillaries along a pressure gradient

flow- through system

water moves only in one direction so that the gills are constantly in contact with fresh, oxygenated water

tracheal systems for gas exchange

body of insect is covered by numerous tiny openings, spiracles

- oxygen will pass from the spiracles into tracheae which eventually become small enough to provide every cell in the insect with oxygen

spiracles

tiny openings that an insect is covered in and oxygen will pass through these openings to trachea

lungs

used by vertebrates for gas exchange

negative pressure filling

how lungs function

- the pressure of air in the lungs is decreased below that of the environment in order to create a pressure gradient that draws air into the lungs

boyles law

the pressure and volume of a gas are inversely related

vertebrates expand their chest cavities (through inhalation) which air from the atmosphere to move into the lungs (which are at lower pressure)

nose

only visible portion of the respiratory system

provides an airway for respiration, moistens and warms air, filters and cleans inspired air, serves as a resonating chamber for speech and houses the olfactory receptors

nasap septum

divides the internal nasal cavity which is formed by the vomer bone, the perpendicular plate of the ethmoid and cartilage

internal nasal cavity

posterior to the external nose

- nasal septum, olfactory mucosa, respiratory mucosa,

how does air enter the internal nasal cavity

nostrils

olfactory mucosa

lines much of the nasal cavity & contains small receptors

respiratory mucosa

pseudostratified ciliated columnar epithelium

- contains goblet cells: the mucus trans microorganisms that enter the nasal cavities

- capillaries and thin walled veins act to warm incoming air as it flows over the mucosa

pharynx

the throat

funnel-shaped tube that connects the nasal cavity and mouth superiorly to the larynx and esophagus inferiorly

nasopharynx

posterior to the nasal cavity, this serves only as an air passageway

during swallowing, the uvula moves to close off the nasopharynx, thus preventing food from moving into the nasal cavity

what is the purpose of the uvula

to prevent food from moving into the nasal cavity by moving to close off the nasopharynx during swallowing

pharyngeal tonsil (adenoid)

located posterior wall of the nasopharynx

trap and destroy pathogens entering the nasopharynx via air

what can happen if tonsils are enlarged

can block the flow of air through the nose and into the throat

air is not properly warmed before entering the lungs and a person may wind up breathing through their mouth

auditory (eustachian) tubes

drain the middle ear cavity to equalize pressure in the eat with atmospheric pressure

oropharynx

posterior to the oral cavity, open into the mouth through the fauces

both swallowed food and inhaled air pass through here

palatine tonsils

in the posterior wall of the oral cavity

lingual tonsils

overs the base of the tounge

laryngopharynx

opens into the larynx

passageway for food

this structure is continuous with the esophagus

larynx

voice box that lies at the upper end of the trachea, just below the pharynx

functions: open airway, routes food and air into the proper channels, voice production

thyroid cartilage

large, formed by 2 attached cartilage plates

adams apple

cricoid cartilage

sits atop and is anchored to the trachea

epiglottis

flexible, composed of elastic cartilage and is covered by taste buds

glottis

hollow opening between the vocal cords

inhaling vs swallowing action of the epiglottis

when air passes into the larynx, epiglottis remains open

when swallowing, larynx pulls the epiglottis to keep food out of the larynx

cough reflex

meant to expel any materials that slip pass the epiglottis

true vocal cords

folds of elastic fibers which are stretched across the opening the. larynx. Appears while because they are avascular

these folds vibrate as air rushed up from the lungs; thus, producing sound

false vocal cords

superior to the true vocal cords

do not produce sound, only involved in helping to close the glottis during swallowing

trachea

the windpipe

connects the larynx to the bronchi

wall consists of a respiratory mucosa that contains cilia and goblet cells

how does smoking influence the trachea

will inhibit i overall activity as smoking often destroys cilia in the trachea

this is what causes coughing the only way to remove mucus from the trachea

trachea & cartilage

trachea is composed of 16-20 C-shaped rings of hyaline cartilage which provides the trachea with a great flexibility which allows the esophagus to expand during swallowing

bronchi & bronchial tree

are where respiratory structures are first encountered

primary bronchi

formed where the trachea branches (near C7)

- right is wider and shorter; therefore, more common site for objects to become lodged

secondary bronchi

three in right lung and two in left lung

bronchioles

passageways smaller than 1mm; smallest is the terminal bronchioles/ alveolar ducts

alveoli

air sacs at the ends of alveolar ducts

site of gas exchange

about 3 million per lung

alveolar sacs

clusters of alveoli

surfactant

chemical secreted into the alveoli which reduced the attraction of water molecules for each other

allows the alveoli to open and fill with air

mediastinum

separated left and right lungs

hilum

located on the medial surface of the lung

pulmonary blood vessels and primary bronchi enter the lung through this opening

pleura

form a thin, protective, double layered serous membrane around each lung

parietal pleura

covers the thoracic wall and superior portion of the diaphragm

visceral pleura

covers the external surfaces of the lungs

pleural cavity

space between the two pleura membranes; filled with pleural fluid

inspiration

the period when air flows into lungs

diaphragm and external intercostals contract to increase the volume of the thoracic cavity, this causes the intrapulmonary pressure to decrease and air to flow in

expiration

the period when air flows out of the lung

depends on lung elasticity

muscles relax and volume decreases, intrapulmonary pressure increases and air flows out

atmospheric pressure

the pressure exerted by the air (gases) surrounding the body

intrapulmonary pressure

the pressure in the alveoli

rises and falls with the phases of breathing, but it always eventually equalizes with atmospheric pressure

intrapleural pressure

pressur ein the pleural cavity

internal respiration

period when air flow s into the lungs

external respiration

the movement of oxygen into the blood from the lungs and carbon dioxide out blood into lungs

internal respiration (capillary gas exchange mechanism)

movement of oxygen from the blood to the tissue cells and of carbon dioxide from tissue cells to blood

- oxygen pressure is always lower in tissues than in the surrounding systemic arterial blood; thus, oxygen moves from the alveoli into the blood

how is oxygen transported in the blood

1. oxyhemoglobin complex

2. dissolved in plasma (small amount)

how is carbon dioxide transported in the blood

1. dissolved in plasma (10%)

2. carbaminohemoglobin (20&)

3. bicarbonate ion (70%)

inspiratory center

in the medulla

- impulses from neurons are sent to the phrenic and intercostal nerves which force the diaphragm and intercostal muscles to contract

as a result, the thorax expands and air rushes into the lungs

pneumotaxic center

sends impulses that inhibit the inspiratory center of the medulla

acts to regulate the rhythm of breathing

pons

pulmonary irritant reflexes

accumulation of mucus, dirt and debris in the respiratory system leads to constriction of air passageways which leads to COUGH

inflation reflex

involves impulses form the brain that inhibit inspiration. this is initiated by stretch receptors associated with the lungs

hyperventilation

occurs when the depth and rate of breathing are increase in response to an increase in CO2 levels in the blood

atelectasis

collapsed lung

chronic obstructive pulmonary disease (COPD)

long term obstruction of air flow: bronchitis and emphysema

bronchitis

inflammation of the bronchi which leads to excess mucus production

emphysema

long term exposure to chemicals (especially nicotine) that leads to destruction of the alveoli

asthma

interruption of air flow that. leads to wheezing and dyspnea (labored breathing)

common cold

infection of the upper respiratory system by the rhino virus

rhinitis, laryngitis, sinusitis

inflammation of the mucosa of the listed structures

influenza

viral infection of the respiratory system

pneumonia

acute inflammation of the alveoli

pleurisy

inflammation of the membranes around the lungs which leads to decrease in pleural fluid

tuberculosis

inflammation of the lungs caused by the bacterium mycobacterium

pulmonary edema

fluid accumulation in the lungs

pulmonary embolism

blood clot that prevents blood from reaching a portion of the lungs

may result in cardiac arrest

basic functions of the excretory system

removing soluble wastes from body fluids; maintaining ion, nutrient and water balance in the animal body; removing nitrogenous wastes from protein and nucleic acid metabolism from the body

what are the three forms of nitrogenous wastes

ammonia, urea, and uric acid

structures/organs that filter wastes in an animals body

gills, lungs, kidneys, body surfaces (skin)

ammonia and ammonium ions

most toxic of nitrogenous wastes

most common in aquatic animals (excrete as soon as formed)

ADVANTAGE: no energy

DISADVANTAGE: need lots of water

differences in ammonia/ammonium ion excretion in aquatic animals

marine invertebrates: across skin and gills

freshwater + marine fishes: gills and kidneys

urea

produced by all mammals, most amphibians, some marine fishes, some reptiles and some terrestrial animals

ADVANTAGES: less toxic than ammonia so animals can tolerate small accumulation; doesnt require large amounts of water

DISADVANTAGE: requires moderate amount of energy for its formation and breakdown

uric acid

produced by birds, insects and most reptiles

- less toxic than ammonium

- HIGH ENERGY COST

semisolid material because it is not soluble in water (NO WATER LOSS)

filtration

removal of solutes (that are dissolved in water) from the liquid in the organism (for humans the liquid is blood, hemolymph and interstitial fluid)

reabsorption

material in the filtrate is recaptured and returned to the blood (essential nutrients are reclaimed)

- common characteristic of the mammalian kidney

secretion

animals excrete solutes from the body in greater quantities then those found in the initial filtrate

- some solutes are actively transported from the blood interstitial fluid into the passageways associated with the excretory organ

excretion

removal of harmful materials from the body

difference between urine and filtrate

filtrate is known as urine after reabsorption; filtrate is the initial material post filtration

URINE IS WASTE

protonephridia

a series of branching tubes in flat worms and other invertebrates

- filter fluids from the body cavity by means of ciliated cells that line the inside of flame cells

- cilia beat to force the fluid through slits in flame cells; solutes and reabsorbed and excess water and wastes exit

metanephridia

found in each segment of an earthworm's body

collect nitrogenous wastes from body fluid and empty these wastes dissolved in water to the outside of the body. important solutes are reabsorbed into the body via active transport

Malpighian tubules

found in insects

series of narrow tubes: waste materials and water are transported into the lumen or opening and then moves to the back of the insects body

urine pathway for excretion

urine collected in renal pelvis -> ureters -> urinary bladder -> urethra

renal cortex

light colored, superficial region of the kidney that has a granular appearance

renal medulla

contains renal pyramids/ papilla