Week 1 - CO Poisoning, O2 transport

Question 1

Narcolepsy

Answer 1

Rare, long-term brain condition that results in sleep at inappropriate times (suddenly, all day drowsiness, cataplexy, sleep paralysis are all manifestations)

May be caused by a lack of the brain chemical hypocretin (orexin)

Question 2

Sleep apnoea - what are the two types?

Answer 2

pauses in breathing / periods of shallow breathing during sleep, which can be caused by a blockage (OSA) or lack of effort to breath (CSA). Being overweight is a risk factor.

Question 3

Insomnia

Answer 3

A broad term for many types of trouble sleeping including inability to fall asleep or stay asleep during the night. It is often caused by psychological/mental health issues such as anxiety and depression or environmental factors

Question 4

Glasgow Coma Scale - definition

Answer 4

test to determine the level on consciousness following a traumatic brain injury
E - Eye response
V - Verbal response
M - Motor response

Question 5

Glasgow Come Scale - ratings

Answer 5

E - Eye response (4-NT)
Spontaneous, sound, pressure, none, NT

V - Verbal response (5-NT)
Orientated, confused, non-coherent words, sounds, none, NT

M - Motor response (6-NT)
obeys command, localising to pressure, normal flexion, abnormal flexion, extension, none, NT

Severe: GCS 8 or less
Moderate: GCS 9-12
Mild: GCS 13-15

Question 6

AVPU scale - definition and ratings

Answer 6

AVPU scale - test to determine level of consciousness (simplified version of the GCS)

Alert - awake, open eyes, respond to voice, bodily control

Verbal - Some sort of response when you speak to them (whether eyes, sounds, motor response)

Pain response - Response upon mild pain stimulus (trapezoid pinch, finger pinch, above eye pinch)

Unresponsive - No eye, voice or motor response to either verbal or pain queues

Question 7

Normal temperature range

Answer 7

Approx 36-38 C

Question 8

Normal pulse range

Answer 8

Approx 60-100

Question 9

Normal respiration rate

Answer 9

Approx 12-20

Question 10

Normal blood pressure

Answer 10

120/80

Question 11

Normal O2 saturation

Answer 11

between 80-100 mmHg or 95-100% pulse ox

Question 12

How to assess circulation in a patient - 4 ways

Answer 12

Bumucosa cyanosis - blue skin on lips, tongue, mucous membranes implying lack of oxygen in blood
Peripheral cyanosis - Blue skin in hand, feet, limbs
Capillary refill - End of finger should refill in 3 seconds after being squeezed
Distal pulse - pulse at wrists and ankles

Question 13

How is oxygen transported?

Answer 13

Two methods

Mostly (97%) in haemoglobin and the remainder in plasma

Question 14

How is CO2 transported?

Answer 14

Four different ways

1. In plasma as a gas (a few %)
2. Mix with water in blood plasma to form H+ ions and bicarbonate (a few more %)
3. Mix with water in red blood cells to form H+ ions and bicarbonate (carbonic anhydrase on RBC membrane makes the reaction more rapid) (approx 70%)
   - Transporter protein trades the bicarbonate with chloride and H+ is picked up by haemoglobin
4. CO2 binds with haemoglobin - carbaminohaemoglobin (HbCO2)

Question 15

Bicarbonate in blood

Answer 15

Bicarbonate is important buffer within plasma - an important ‘blood gas’, low bicarbonate would indicate another issue

Question 16

How does carbon monoxide poisoning work?

Answer 16

After carbon monoxide is breathed in, it enters your bloodstream and mixes with haemoglobin (the part of red blood cells that carry oxygen around your body) to form carboxyhaemoglobin.

Shifts curve so far left that it can’t release oxygen
Affects bodies ability to make ATP

Question 17

Describe oxygen dissociation curve

Answer 17

The shape of the curve is SIGMOID, determined by the nature of positive cooperativity (i.e. When one oxygen attaches to haemoglobin, the affinity for oxygen increases until the haemoglobin reaches 100% saturation - 4 oxygen molecules)

Question 18

Partial pressure

Answer 18

In a mixture of gases, each constituent gas has a partial pressure which is the notional pressure of that constituent gas if it alone occupied the entire volume of the original mixture at the same temperature

Question 19

Dalton’s Law

Answer 19

Total Pressure = Sum of all partial pressures

Question 20

Henry’s Law

Answer 20

Mass of dissolved gas (at given volume, equilibrium) is proportional to the partial pressure of the gas
“…when a gaseous mixture (e.g., the atmosphere) is in contact with a solution, the amount of any gas in that mixture that dissolves in the solution is in direct proportion to the partial pressure of that gas”
I.e. When there is more oxygen present, more oxygen moves into the bloodstream

Question 21

Carboxyhaemoglobin

Answer 21

haemoglobin and carbon monoxide

Question 22

Oxyhaemoglobin

Answer 22

oxygenated haemoglobin (deoxy is de-oxygenated haemoglobin)

Question 23

Methaemoglobin

Answer 23

iron molecules in the ferric state (Fe3+) rather than the ferrous state (Fe2+) which means it cannot bind to oxygen.

Question 24

When the oxygen dissociation curve moves to the left or the right, what does this mean?

Answer 24

Left for lungs - Left shift indicates higher affinity for oxygen to encourage binding to haemoglobin in the lungs
Right for muscles - Indicates lower affinity of haemoglobin for oxygen, due to bodies need for more oxygen (such as in working muscles)

Factors that determine shift include:

• TEMP - when temperature INCREASES, shifts right to encourage further oxygen in tissues
• 2-3 DPG
• H+ IONS
• CO2 - increased presence of CO2 shifts right, as it means muscles are creating energy which requires oxygen (and CO2 is a bioproduct that needs to be carried away)

Question 25

Give an overview of glycolysis: input, products, where it takes place 

Answer 25

Glucose (6C) from food is broken down into two pyruvate (3C), as it is a simpler format to extract energy Input: Glucose (6c) Output: 2 pyruvate (3c) + 2ATP (net) + 2NADH Where: cytoplasm / cytosol

Question 26

Give an overview of the Krebs Cycle, describing input/s, key intermediate stages and products and where it takes place

Answer 26

Input: Acetyl CoA Citrate (6c), oxaloacetate (4c) Output: Per cycle - 3x NADH, 1x FADH, 1x ATP, 2 CO2 as waste Where: mitochondria - outer membrane

Question 27

Intermediate step between glycolysis and Krebs cycle

Answer 27

Pyruvate is transformed into Acetyl CoA, which then begins the citric acid cycle.

Question 28

Give an overview of the electron transport chain/ oxidative phosphorylation, describing input/s, key intermediate stages, products and where it takes place

Answer 28

All of the electrons removed from the processes so far are carried by NADH and FADH to start the electron transport chain. Simply, redox reactions occur as electrons are transferred from their donors (NADH/FADH) to the acceptors (Oxygen). This process fuels ATP synthase, which is the main producer of the ATP required for cell processes Input: NADH, FADH, electrons, oxygen as transporter Output: 34/36 ATP, H2O as waste Where: mitochondria - inner membrane

Question 29

What happens when oxygen is not present? (describe anaerobic respiration)

Answer 29

Anaerobic respiration occurs when oxygen is not present (for example, when athletes need energy quickly). Glycolysis still occurs - glucose to pyruvate Pyruvate then turned into lactic acid OUTPUT: NAD+ The biproduct (waste) of this process is lactic acid rather than CO2 and H2O

Question 30

How has respiration been impaired by CO? (two ways)

Answer 30

Binding with haemoglobin to restrict oxygen uptake | Binding with cytochrome c oxidase which impacts ability to transport electrons

Question 31

What is the central nervous system?

Answer 31

brain and spinal cord - CONTROL CENTER

Question 32

What is the peripheral nervous system?

Answer 32

cranial / spinal nerves - COMMUNICATION LINES

Question 33

What is the somatic nervous system?

Answer 33

Controls VOLUNTARY muscles and transmits sensory information to CNS

Question 34

What is the autonomic nervous system?

Answer 34

Controls INVOLUNTARY body functions

Question 35

What are the parasympathetic and sympathetic nervous systems?

Answer 35

Parasympathetic - CALMS body to conserve/maintain energy | Sympathetic - AROUSES body to expend energy

Question 36

Cells types in nervous system

Answer 36

Neurons - send signals Glial cells - provide support, digestion, insulation in CNS and PNS PNS - Schwann and satellite cells CNS - astrocytes, microglia, oligodendroglia

Question 37

Resting potential

Answer 37

difference in voltage between the inside and outside of the neuron

Question 38

Action potential

Answer 38

occurs when a neuron sends information down an axon, away from the cell body.

Question 39

Sodium pump

Answer 39

sodium and potassium both need to move across the nerve cell membrane through active transport. Unequal distribution inside and outside generate the electrical impulses required to send messages

Question 40

Introduction / consent

Answer 40

Obtaining consent from patients, discussing confidentiality  - Who you are - name and role - What is the purpose - our learning - How long will it take - outline amount of time it will take to gather information  - What will happen to the information / who will you share it with - passing any details on to doctor / medical team - What if they say no - if you don’t want to talk, won’t affect your care Initiating consultation (consent above) - Introduction: Role as medical student - to learn, to listen, to understand, as conduit to doctor (need to make it clear that you will share any information shared with doctor) - Establish purpose - Consent - Establish rapport - Establish comfort

Question 41

Describe respiratory system gross anatomy

Answer 41

``` Nasal / oral cavity Pharynx Larynx Trachea Right / left Bronchus Right - three bronci left - two bronchi Bronchioles Alveolus ```

Question 42

Describe alveolus structure and function

Answer 42

Terminal end of the lung capillaries, where gas exchange occurs Macrophages Pneumocytes - Type 1: gas exchange, squamous (flat) / thin Type 2: secretion of surfactant, cuboidal Pulmonary surfactant: is a mixture of lipids and proteins which is secreted into the alveolar space by epithelial type II cells. The main function of surfactant is to lower the surface tension at the air/liquid interface within the alveoli of the lung

Question 43

Gibb's reflective cycle

Answer 43

Description, feelings, evaluation, analysis, conclusion, action plan

Question 44

Differences between left and right lung

Answer 44

Left - smaller to make room for heart, 2 lobes | Right - longer and more upright, 3 lobes

Question 45

Functional residual capacity of the lungs

Answer 45

Maximum expiration (breathe out) + residual volume (what's left)

Question 46

Cellular respiration

Answer 46

process of converting biochemical energy to ATP

Question 47

Hamburger shift

Answer 47

Exchange of bicarbonate ions and chloride ions across membranes of RBCs

Question 48

Haldane effect

Answer 48

Left for lungs, haem has high affinity to pick up oxygen

Question 49

Bohr effect

Answer 49

Right for muscle, haem has low affinity for oxygen to drop off oxygen in tissues

Question 50

Carbaminohaemoglobin

Answer 50

Carbon dioxide binds with oxygen

Question 51

Three examples of exclusion criteria for anatomy body donors

Answer 51

Obesity Post-mortem examination Some infectious diseases - hepatitis, HIV/AIDS

Question 52

Describe key points from Human tissue act of 2004

Answer 52

Permits with consent donation of whole bodies for anatomical examination following certified/registered death Must be licensed to examine the body, removal of body parts / organs, storage

Question 53

Describe the Calgary Cambridge model of communication

Answer 53

Initiate, gather information, physical examination, explanation / planning, close the session (all supported by structure and relationship building)

Question 54

What is consent? Three factors

Answer 54

Consent means a voluntary, uncoerced decision, made by a competent person on the basis of adequate information and deliberation, to accept some proposed course of action INFORMED COMPETENT VOLUNTARY

Question 55

Oxygen cascade

Answer 55

pO2 drops at every step from atmospheric gas to mitochondria (from about 21kPa to 3kPa)

Question 56

Conducting zone of the respiratory system

Answer 56

Trachea, bronchi, bronchioles, terminal bronchioles

Question 57

Transitional and respiratory zones of the respiratory system

Answer 57

Respiratory bronchioles, alveolar ducts, alveolar sacs

Question 58

What determines oxygen delivery? (two elements)

Answer 58

Cardiac output x oxygen content

Question 59

Where is oxygen stored? (three locations and approximate amounts)

Answer 59

Lungs - 450ml Blood - 850ml Dissolved and in tissues - 250ml

Question 60

What is a clinical skill?

Answer 60

Any discrete and observable act within the overall process of patient care

Question 61

Describe the parts of a neuron

Answer 61

Soma with a cell body and dendrites Long axon (nerve fiber) covered in myelin separated by nodes of ranvier Ends with terminal boutons

Question 62

What are the 4 basic types of a neuron?

Answer 62

Bipolar Unipolar Multipolar Pyramidal

Question 63

What are the functions / characteristics of a neuron? (3 processes)

Answer 63

Receive, process and generate signals –Action potentials –Chemical neurotransmission (synapses) –Electrical neurotransmission (gap junctions) THEY DO NOT PROLIFERATE (exception: neural stem cells)

Question 64

What is the basic process of a synapse?

Answer 64

Nerve impulse triggers release of neurotransmitters into synaptic gap Channel opens and nerve impulse sent (without neurotransmitter, channel closed, no signal sent)

Question 65

Describe the three types of glial cells in the CNS

Answer 65

Astrocyte - clean up, transport, stability, digestion, regulation Microglia - digestion Oligodendroglia - insulation

Question 66

Describe the two types of glial cells in the PNS

Answer 66

Satelitte cells - support | Schwann cells - insultation

Question 67

What are the meniges of the CNS? (6 layers)

Answer 67

Skin, periosteum, bone, dura mater, arachnoid, pia mater

Question 68

What are the functions of CSF? (four)

Answer 68

Buoyancy Protection Chemical stability Prevention of brain ischaemia (restriction of blood vessels to brain)

Question 69

What are the lobes of the brain? (six)

Answer 69

``` Frontal Parietal Occipital Temporal Brain stem Cerebellum ```

Question 70

What are the three part of the brain stem?

Answer 70

Midbrain Pons Medulla

Question 71

What are the regions of the spinal cord? 4 with corresponding vertebrae & post-spine region

Answer 71

``` Cervical (C1-8) Thoracic (T1-12) Lumbar (L1-5) Sacral (S1-5) Conus / Cauda equina ```

Question 72

Regions for dermatomes (5)

Answer 72

``` Trigeminal Cervical Thoracic Lumbar Sacral ``` Only make sense if person is on all fours

Question 73

Define eteroceptors, proprioceptors, enteroceptors

Answer 73

Exteroceptors- respond to stimuli outside the body Special senses (e.g. photoreceptors, olfactory neurones, cochlear hair cells) and body surface (e.g. mechanoreceptors, chemoreceptors….) Proprioceptors- Stimuli from muscles tendons and joints. Enteroceptors (visceroceptors) - Internal surfaces such as walls of viscera, blood vessels.

Question 74

What are mechanoreceptors?

Answer 74

Type of exteroceptor subdivided by sensation (vibration, temperature, touch for example)

Question 75

What is the CNS blood supply?

Answer 75

Arteries - carotid, vertebral (circle of Willis, Cerebral arteries) Veins - venous sinuses, jugular veins

Question 76

Describe the circle of willis

Answer 76

Can be seen from inferior view of brain | Brings together the Internal carotid artery, middle cerebral artery and the basilar artery

Question 77

What is the McWhinney model?

Answer 77

Patient centred approach Patient presents problem, gather information, parallel search of two distinct frameworks (DISEASE / DOCTOR and ILLNESS / PATIENT), which are then integrated and used collaboratively

Question 78

What is the vital capacity of the lungs ?

Answer 78

Inspiratory reserve volume + Tidal volume + expiratory reserve volume

Question 79

What is the functional residual capacity of the lungs?

Answer 79

Expiratory reserve volume + residual volume

Question 80

What is your normal breathing at rest called?

Answer 80

Tidal volume

Question 81

What’s the difference between gap junction and synapse

Answer 81

A gap junction is called an electrical synapse in neurons and nerves. So an electric synapse is a specific type of gap junction, namely the electrically conductive link between two neighboring neurons. A chemical synapse is a biological junction through which neurons’ signals can be exchanged. A chemical synapse is not a gap junction, because of the 20 to 40 nanometer distance that separates the cells.