Module 3: Section 1 - Exchange and Transport Flashcards
alveoli?
tiny air sacs that consist of
epithelial cell layer
elastic fibres
collagen
bronchi?
divisions of trachea that consist of small tubes
suppoted by incomplete rings of cartilage
cartilage?
rings are incomplete to bend
strong & flexible to stop organs from collapsing
connective tissue
provide support
smooth muscle?
involuntary muscle
found in walls of trachea and bronchi
controls organs diameter in tubes so when relaxed they widen
cilliated epithelium (cillia)?
beats bacteria containing mucus upwards away from alveoli towards throat (swallowed) to prevent infection
tiny-hair like cillia
goblet cells?
secrete mucus into trachea lining
mucus traps harmful microorganisms and dust particles preventing enter to lungs
elastic fibres?
allow alveoli to stretch as air is inhaled + recoil as air is exhaled
found in trachea, bronchi, brochioles
bronchioles?
small divisions of bronchi
trachea?
primary airway which carries air from nasal cavity to the chest
ventilation?
movement of fresh air into lungs and stale out via expiration/inpiration
what does trachea contain?
C cartilage
smooth muscle
elastic fibres
goblet cells
cilliated epithelium
what does bronchi contain?
Small cartilage
smooth muscle
elastic fibres
goblet cells
cilliated epithelium
what does alveoli contain?
elastic fibres
squamous epithelium
what does bronchioles contain?
smooth muscle
elastic fibres
goblet cells
cillia
why do we need exchange surfaces?
to exchange mats such as urea water and oxygen ACROSS PLASMA MEMBRANES
squamous epithelium?
Flat, scale-like epithelial cells
thin walls for quick diffusion pathway
diffusion is quick when? why?
the SA:V is greater
diffusion is slow when? why?
the SA:V is smaller
as larger organisms cells have no direct contact with external environment so diffusion distance is larger
why do larger organisms have specialised exchange surfaces?
as they have higher metabolic rate and smaller SA:V so require more oxygen and glucose
adaptations for alveoli?
layer of squamous epithelium cells for quick diffusion pathway
partially permeable to allow certain gases across
ventiliation of air for a steep diffusion gradient
large SA to increase rate of gas exchange
good blood supply so gas exchange can be transported
ribcage?
consist of ribs that enclose the thorax (chest)
diaphragm?
sheet of muscle that moves the ribcage up and out when it contracts
external intercostal muscles?
found between the ribs
pull the ribcage up and out when they contract
internal intercostal muscles?
found between the ribs pull the ribcage down and in when they contract
pleural cavity?
found in thoracic cavity
double membrane
filled with pleural fluid that lubricates lungs
adheres to thoracic cavity and lungs via water cohesion so lungs expands whilst breathing
inspiration?
active process requiring energy for muscle contraction
expiration?
a passive process
events of inspiration?
- external intercostal muscles contract while internal intercostal muscles relax, moving the ribcage up and out
- The volume of the thoracic cavity increases
- diaphragm contracts and flattens, further increasing the volume of the thoracic cavity
- lung pressure decreases below atmospheric pressure
- Air flows into the lungs down the pressure gradient
events of expiration?
- external intercostal muscles relax, moving ribcage down and in
- The volume of the thoracic cavity decreases
- diaphragm relaxes and unflattens, further decreasing the volume of the thoracic cavity
- lung pressure increases above atmospheric pressure.
- Air is forced out of the lungs down the pressure gradient.
