8.2 Breathing and Respiration in special circumstances - METABOLISM, INFANCY, OLD AGE, OBESITY, FEAR, PREGNANCY Flashcards
METABOLISM
what does METABOLISM refer to
the PRODUCTION of ENERGY by burning nutrient molecules
Biochemistry side: the sum of all the chemical reactions taking place in the body (even those not related to energy production)
METABOLISM
why can METABOLIC RATE be thought of as RATE of AEROBIC RESPIRATION
as cellular processes USE MORE ATP,
MORE O2 REQUIRED
MORE CO2 PRODUCED
-> RATE and DEPTH of BREATHING INCREASES to provide O2 and remove CO2
METABOLISM
AEROBIC RESPIRATION EQUATION
C6H12O6 + 6 O2 —> 6 CO2 + 6 H2O + 38 ATP
METABOLISM
ANAEROBIC RESPIRATION EQUATION
C6H12O6 —> 2 LACTIC ACIDS + 2 ATP
(less ATP)
METABOLISM
what happens to the LACTIC ACID produced by ANAEROBIC RESPIRATION
needs to be BROKEN DOWN in LIVER
- using OXYGEN
METABOLISM
where is LACTIC ACID BROKEN DOWN and what does it REQUIRE
in LIVER
REQUIRES OXYGEN
METABOLISM
what is the OXYGEN DEBT
HEAVY BREATHING AFTER EXERCISE to PROVIDE EXTRA O2
- to BREAK DOWN LACTIC ACID
followed by PANTING (short, quick breaths) to allow AEROBIC RESPIRATION to RESUME
METABOLISM
what is the CORI CYCLE (LACTIC ACID CYCLE)
in MUSCLE:
GLUCOSE BROKEN DOWN into 2 PYRUVATE
-> 2 LACTATE
anaerobic respiration
transported to LIVER (by blood)
in LIVER:
2 LACTATE converted to 2 PYRUVATE
-> GLUCOSE
GLUCONEOGENESIS (uses 6 atp)
(and oxygen)
INFANCY
How is BREATHING in a FETUS
NO BREATHING - NO AIR in Amniotic Sac
- RECEIVE O2 and REMOVE CO2 by PLACENTA
INFANCY
when are ATTEMPTS at RESPIRATORY MOVEMENTS made in the FETUS
BY END of 1ST TRIMESTER
- caused by TACTILE and FETAL ASPHYXIA (O2 deprivation)
INFANCY
what happens in the 3RD and 4TH MONTH of PREGNANCY to the FETUS and what does this help PREVENT
- BREATHING MOVEMENTS INHIBITED
- so LUNGS almost completely DEFLATED
- helps PREVENT MECONIUM ASPIRATION (passing and aspiring bowel contents during labour / distress)
INFANCY
what helps PREVENT MECONIUM ASPIRATION of FETUS
DEFLATED LUNGS
INFANCY
what do ALVEOLI do up UNTIL BIRTH and why
ALVEOLAR EPITHELIUM secrete Small amount of FLUID up until birth
- KEEP CLEAN FLUID in LUNGS
INFANCY
what are the MECHANICAL CHANGES at Birth (neonate)
during delivery (passing through birth canal)
- COMPRESSION of LUNGS
- compression of FLUID from the lung
- RECOIL of the CHEST WALL (lungs bounce back from compression) produces PASSIVE INSPIRATION of AIR
NEGATIVE INSPIRATORY PRESSURES up to 70-100 cm H2O are INITIALLY REQUIRED to expand alveoli
INFANCY
in NEONATE why are NEGATIVE INSPIRATORY PRESSURES INITIALLY REQUIRED (70-100 cm H2O)
to EXPAND ALVEOLI (LaPlace’s Relationship) which FACILITATE LUNG EXPANSION
by OVERCOMING:
- AIRWAYS RESISTANCE
- INERTIA of FLUID in AIRWAYS
- SURFACE TENSION of the AIR/FLUID INTERFACE in ALVEOLUS
INFANCY
LaPlace’s Relationship - how does EXPANDING ALVEOLI facilitate LUNG EXPANSION
by OVERCOMING
- AIRWAY RESISTANCE
- INERTIA of FLUID in AIRWAYS
- SURFACE TENSION of AIR/FLUID INTERFACE in ALVEOLUS
INFANCY
NEONATE- NEGATIVE INSPIRATORY PRESSURES of up to… are usually required
70-100 cm H2O
INFANCY
after birth what causes PASSIVE INSPIRATION of Air into LUNGS
RECOIL of LUNGS after compression
(fluid also squeezed out)
INFANCY
CHEMICAL EVENTS that take place at BIRTH (lead to initiation of breathing)
- cutting Umbilical Cord REMOVES O2 SUPPLY
-> ASPHYXIA (Lack O2)
LOW O2, HIGH CO2, LOW pH
-> ACIDOSIS
Acidotic state stimulates
RESPIRATORY CENTRES in MEDULLA
and (PERIPHERAL) CHEMORECEPTORS in CAROTID ARTERIES
-> INITIATE BREATHING
INFANCY
what does baby immediately DEVELOP after CUTTING UMBILICAL CORD
ASPHYXIA (O2 DEPRIVATION)
which leads to ACIDOSIS
INFANCY
how does ACIDOSIS INITIATE BREATHING in NEONATE
STIMULATES RESPIRATORY CENTRES in MEDULLA and CHEMORECEPTORS (peripheral) in CAROTID ARTERIES
- initiates breathing
INFANCY
which SENSORY EVENTS (STIMULUS) can STIMULATE BREATHING in NEONATE
- THERMAL
sudden DROP in TEMPERATURE can cause baby to GASP (MAJOR STIMULUS) - TACTILE
Nerve Endings in SKIN stimulated (may rub baby) - VISUAL
change from dark to LIGHT environment - AUDITORY
SOUND
INFANCY
what STIMULATES SURFACTANT production in NEONATES
- ALVEOLAR DISTENTION, CORTISOL, EPINEPHRINE (adrenaline)
stimulate Type 2 PNEUMOCYTES
INFANCY
how is EXPIRATION in NEONATES
INITIALLY ACTIVE
- PRESSURES 18-115 cm H20 GENERATED
- AMNIOTIC FLUID FORCED OUT from BRONCHI
INFANCY
what forces AMNIOTIC FLUID out in NEONATES
PRESSURES 18-115 cm H2O
INFANCY
what do PHYSIOLOGICAL CHANGES in NEONATES lead to
- INCREASING BLOOD FLOW
- Initating CARDIOVASCULAR CHANGES
INFANCY
how is BLOOD FLOW in Neonates
INCREASING
INFANCY
how is LUNG COMPLIANCE (deformability) in NEONATES vs INFANTS/CHILDREN
- NEONATES: HIGH COMPLIANCY (gives way when subjected to force)
- Elastic fibre develop is postnatally
- Static ELASTIC RECOIL PRESSURE is LOW
CHEST WALL COMPLIANCE HIGH
- cartilaginous ribs
- limited thoracic muscle mass
more prone to atelectasis (lung collapse) and respiratory insufficiency)
- INFANCY/CHILDHOOD
- COMPLIANCY DECREASES
- STATIC RECOIL PRESSURE INCREASES
INFANCY
how long does LUNG DEVELOPMENT continue for
10 YEARS
(MOST RAPID in 1ST YEAR)
INFANCY
how many AIR SACS at BIRTH
Terminal Air Sacs (mostly SACCULES):
20-50 X10^7
1/10th of ADULT NUMBER
INFANCY
development of ALVEOLI FROM SACCULES COMPLETE BY…
18 MONTHS
in OLD AGE
how is the RESPIRATORY SYSTEM different
- DECREASED ELASTIC RECOIL of lung tissues
- DECREASED CHEST WALL COMPLIANCE
- DECREASED STRENGTH in the Respiratory MUSCLES
- INCREASED RESIDUAL VOLUME
- DECREASED VITAL CAPACITY
- DECREASED FEV1
OBESITY
why is increased VISCERAL FAT an issue
- surrounds ORGANS
ABDOMINAL CAIVTY ENLARGED
-> PUSHES DIAPHRAGM UP
-> DECREASED LUNG VOLUME
OBESITY
why is Increased SUBCUTANEOUS FAT an issue
(under skin)
around UPPER AIRWAYS
- can cause to COLLAPSE
(obstructive sleep apnoea)
and around THORACIC CAVITY
- decreased chest wall compliance and recoil
- decreased lung capacity
OBESITY
in HEALTHY person how is CHEST WALL RECOIL and LUNG RECOIL
roughly EQUAL
OBESITY
in HEALTHY person how is OUTWARD PRESSURE and INWARD PRESSURE
roughly EQUAL
OBESITY
how is CHEST WALL RECOIL
INWARD and OUTWARD PRESSURES
LUNG CAPACITY
- DECREASED CHEST WALL RECOIL (and compliance)
- INWARD PRESSURE GREATER than OUTWARD
- DECREASED FRC / DECREASED LUNG CAPACITY
OBESITY
how is LUNG VOLUME
DECREASED
- DECREASED FRC
OBESITY
how is AIRWAYS RADIUS and what can this cause
DECREASED AIRWAY RADIUS
-> ATELECTASIS (collapse)
-> V/Q (VENTILATION/PERFUSION) MISMATCHING
FEAR
ADRENALINE acts on which RECEPTOR in HEART and has what EFFECT
BETA 1
- INCREASE HEART RATE and CONTRACTILITY
FEAR
ADRENALINE acts on which RECEPTOR in LUNGS and has what EFFECT
BETA 2
- BRONCHODILATION
FEAR
ADRENALINE acts on which RECEPTORS on BLOOD VESSELS and has what EFFECT
ALPHA 1 -> VASOCONSTRICTION
BETA 2 -> VASODILATION
EXERCISE:
MUSCLE CELLS RESPIRATION INCREASES
BREATHING RATE INCREASES
MORE GAS EXCHANGE
HEART RATE INCREASES
(signals from brain - Medulla and Pons)
PREGANCY
RESPIRATORY CHANGES - MECHANICAL:
- RIBS FLARE OUTWARDS
- DIAPHRAGM MOVES UPWARDS by 4cm
PREGANCY
by how much does the DIAPHRAGM MOVE UPWARDS
up to 4 CM
PREGANCY
how does TIDAL VOLUME CHANGE
INCREASE by 200 ML
PREGANCY
how does VITAL CAPACITY CHANGE
5% INCREASE vital capacity
(due to 200 ml increase tidal volume)
PREGANCY
how does RESIDUAL VOLUME CHANGE
20% DECREASE residual volume
PREGANCY
how does RESPIRATORY RATE CHANGE
respiratory rate DOES NOT CHANGE
PREGANCY
why does Pregnancy represent a FULLY COMPENSATED ALKALOSIS
- DECREASED PCO2
- PO2 UNCHANGED
- COMPENSATORY DECREASE in HCO3- ions
therefore pH UNCHANGED (normal)
PREGANCY
how is PCO2 different
DECREASED
(compensated for by decrease in HCO3- from kidneys - less reabsorption)
