2. Aerobic health Flashcards
Human Circulatory System
= circulates blood and lymph through body consisting of heart blood vessels, blood lymph and lymphatic vessels/glands
= humans have a closed circulatory system.
- physically separated from the rest of the body
- Consists of vessels and a pump
- Humans have a double circulatory system as our heart is divided completely into right and left sides
In which direction from the heart does an Artery and venous go?
artery = Carries AWAY from the heart
Venous = Returns blood to the heart
The heart
= generates a pressure to forces blood continuously around the body
- composed predominantly of cardiac muscle
- One way flow
- Left side is more muscular as it pumps blood all around the body
- right side only pumps to the lungs
Structure of the heart?
Right Atrium = receives blood from the superior and inferior vena cava and the coronary sinus
Right Ventricle = receives blood from the right atrium and sends blood to the lungs
Left atrium = Receives blood from the pulmonary veins
Left ventricle = Receives blood from the left atrium and sends blood all over the body.
- wall of left ventricle is much thicker than the right as it pumps oxygenated blood all over the body rather than just to the lungs.
- ventricles produce high pressures and are discharging chambers that push the blood back out of the heart
What is the structure and function of the pericardium?
= Sac like structure with two layers.
- keeps the heart contained in the chest cavity
- prevents the heart from over-expanding when blood volume increases
- limits heart motion
- pericardial fluid reduces friction between the two membranes of the serous pericardium.
- Fibrous pericardium = tough, fibrous sac
- Serous pericardium = parietal lay and visceral layer (epicardium)
- Pericardial cavity = in-between the 2 layers of the serous pericardium and contains pericardial fluid
What are the layers of the heart wall?
- Epicardium = outer
- Myocardium = muscle
- Endocardium = inner
Explain the three blood vessels?
Artery
- can withstand pressure
- elastic wall enable to absorb pressure
- can alter in diameter due to blood pressure and environmental changes
- carry blood away from the heart
Capillaries
- microscopic vessels that connect to arterioles and
venule’s
- single layer walls allow for nutrients and waste to
exchange between blood and cells
Veins
- several venules
- carry deoxygenated blood
Heart as a muscle?
= cardiac muscle contraction
- myocardium muscles that contracts through process of
sliding filaments
Intercalated discs unique structural formations found between the myocardial cells of the heart.
what are Intercalated discs?
= unique structural formations found between the myocardial cells of the heart that contain 2 cell junctions:
- Desmosomes = hold fibre structures together so heart doesn’t pull apart.
- Gap Junctions = allows electric pulse to move cell to cell so the heart beats are synchronised.
- they enable the myocardium to behave as a single coordinated unit
The Conduction system
- cardiac muscles auto rhythmic
- cardiac muscles repeatedly generate spontaneous action potentials that then trigger heart contractions
= the conduction system - Resting state - intracellular fluid is more negatively charged then extracellular
- Cells are polarised when electrically stimulated by another cell
Repolarisation vs Depolarisation
REpolarisation = Relaxing (setting back to start)
Depolarisation = electrical activation of myocardium
- contracting - going off or doing something
ECG = sum total of electrical charges of individual cells
Cardiac Cycle
- one cycle consists of contraction and relaxation of both atrias followed by systole and diastole of both ventricles.
Electrical event = depolarising or repolarising
Mechanical event = what is physically happening to the heart.
Influences of the conductive system?
SA node = natural pacemaker
- autorhythmic fibres initiate action potentials most often
Neurotransmitters and hormones from sympathetic nervous system can modify the heart rate and force contractions.
Cardiac muscles generate ATP mainly by aerobic metabolism.
Electrical and mechanical events of an ECG wave
ECG Electrical Mechanical
P Atrial Depolarisation Atrial contraction
QRS Ventricular depolarisation Ventricular contraction
T. Ventricular repolarisation Ventricular relaxation
Describe the sequence of excitation during cardiac conduction.
- SA node
- through atria - causing atrial contraction
- AV node
- AV bundle
- R and L bundle branches
- Purkinje fibres - causes ventricular contraction
What is coronary circulation?
= blood flow to the heart
- delivers oxygen to heart muscles
- left and right coronary artery
- coronary artery = delivers oxygenated blood and nutrients to the heart.
- coronary veins remove CO2 and wasted from myocardium
LEARN PICTURE
Stroke Volume?
Stroke volume is thee amount of blood pumped out of a ventricle in ONE PUMP.
What is Cardiac output?
= is the volume of blood ejected from left or right ventricle into aorta EACH MINUET.
CO = stroke volume ml/b X Heart rate (bpm)
Regulation of Stroke Volume (3 factors)
- Preload
= amount ventricles are stretched by contained blood
prior to contraction - Afterload
= force at which heart has to contract to eject blood - Contractibility
= ability to self contract
What are Heart Valves?
= control flow of blood through heart preventing back flow
- controlled by pressure differences
Tricuspid, Pulmonary, Mitral, Aortic valve
Murmor = faulty blood flow in heart
What is Blood pressure and what is affected by?
= the pressure exerted by the blood against the walls of the arteries
affected by:
- cardiac output
- peripheral resistance
- Viscosity and blood volume
Blood Pressure is determined by Cardiac output and Vascular resistance
What is Vascular resistance (R)?
= the opposition to blood flow due to friction between blood and walls of vessels.
What is venous return?
= the volume of blood flowing back to heart through systemic veins occurs due to the pressure generated by contractions fo the hearts left ventricle.
Mean Arterial Pressure (MAP)
= how much O2 is getting into tissues.
- valve is important because it is the difference between MAP and venous pressure that drives blood through capillaries of organs.
The Respiratory system
Breathing and respiratory:
- Respiration is the exchange of gases between the atmosphere, blood and cell.
Combination of 3 processes is required for respiration to occur:
- Ventilation (breathing)
- External (pulmonary) respiration
- Internal (tissue) respiration
What is the reason for breathing?
- supply O2 to blood
- remove CO2 from blood
What are two structural parts and two functional parts of the respiratory system?
And what do they consist of?
Structural :
- Upper: nose, pharynx and associated structures
- lower: Larynx, trachea, bronchi and lungs
Functional - Conducting and respiratory zone
upper Respiratory System anatomy
Larynx = passage that connects pharynx and trachea
- contains vocal folds which produce sound when
vibrates (vocal box)
Trachea = extend from larynx to primary bronchi
Bronchi = at 5th thoracic vertebrae the trachea branches into right primary bronchi which enter right lung and left primary bronchi which enters left lung
- upon entering lungs primary bronchi divide into
smaller branches
- terminal bronchioles are at the end of conducting
zone
What is the conducting zone?
= filter, warm and moisten air and conduct it into lungs
- made of the nose, pharynx, larynx, trachea, bronchi, bronchioles, terminal bronchioles
Lower Respiratory System anatomy
Lungs = paired organs in thoracic cavity
- enclosed and protected by pleura membrane
Alveoli = respiratory zone terminates at the alveoli and air sacs are found within the lungs
Respiratory zone
= respiratory bronchioles and alveolar ducts (10% gas exchange)
- Aioli (90%) gas exchange
Alveolus
2 kinds of cells
- Type 1 = gas exchange
- Type 2 = produce surfactant
- helps create surface tension and prevents alveoli
from collapsing
- helps create surface tension and prevents alveoli
What is Dead space ?
= amount of air inhaled which does not take part in the gas exchange
what is gas exchage?
= respiration
= uptake of O2 from atmosphere and discharge of CO2 back into the environment
- diffuse from region of high partial pressure to region of low
Negative pressure breathing
- to move O2 from atmosphere into lungs the pressure must be lower in lungs
= pulling the air in - achieved by expansion of chest wall muscle contraction.
How does gas exchange at the alveoli work?
Millions of alveoli in lungs = huge surface area
- allows O2 to diffuse rapidly across the membrane into surrounding capillaries for dispersal around the body
Blood supply to the lungs
Blood enters via:
- pulmonary arteries (pulmonary circulation)
- Bronchial arteries (systemic circulation)
Blood Exists via:
- pulmonary veins
What is pulmonary ventilation?
= the inhalation (inflow) and exhalation (outflow) of air and involves the exchange of air between the atmosphere and alveoli in the lungs
- air flows between because of the altering pressures created through contraction and relaxation of respiratory muscles.
Air moves in - pressure in lungs is lower than atmosphere
Air moves out - pressure in lungs is higher than atmosphere
What is the significance of smooth muscle?
= enables control of diameter of airways in relation to rate of of gas exchange
How does Pleura effect breathing ?
= reduces friction during breathing
- lines thoracic wall and diaphragm and onto lungs
- helps to create negative pressure (breath in) and positive pressure (breath out)
Factors affecting Pulmonary ventilation?
- Surface tension of the alveolar fluid
- elastic recoil - decreases size of alveoli during expiration
- compliance - how much effort is required to stretch the lungs and chest wall
What is the respiratory membrane comprised of
The respiratory membrane is comprised of
1. A layer of type 1 and 2 alveolar cells and associated
alveolar macrophages that constitutes the alveolar
wall
- Surfactant layer and squamous cell of alveolar
wall
- An epithelial basement membrane underlying the alveolar wall
- A capillary basement membrane that is often fused to the epithelium basement membrane
- The capillary endothelium(capillary wall)
Lung volumes:
Expiratory reserve capacity (EVR)
= max volume of air that can be voluntarily exhaled
Lung volumes:
Functional residual capacity FRV
= volume left in the lungs at the end of a normal breath
Lung volumes:
Inspiratory capacity (IC)
= max volume that can be inhaled
Lung volumes:
Inspiratory reserve capacity (IRC)
= max volume inhaled above tidal volume
Lung volumes:
- Tidal volume
- Total lung capacity
- Vital capacity
Tidal = normal breathing
TLC = entire volume of lung
Vital = max volume that can be inhaled and exhaled
Internal and external respiration
At higher pressure O2 binds to haemoglobin more
External = O2 diffuse from alveoli into pulmonary capillaries
Internal = O2 diffuse from systemic capillaries into tissues
How is O2 transported in the blood
- 97% carried attached to haemoglobin = oxyhemoglobin
- 3% dissolved in plasma
The oxygen- haemoglobin dissociation curve
= shows the relationship between haemoglobin saturation and Po2 at normal temp
(partial pressure of O2 on x axis and oxygen saturation y
axis)
- shows how many o2 bind to the haemoglobin
- when you need more O2 in the tissues the haemoglobin with have less affinity for O2 because it is needed in the tissues
- when more affinity the O2 isn’t needed by the tissues
e. g. running - less affinity because O2 is needed by tissues
Cyanosis
= oxygen not reaching extremities
- bluish discolouration of skin
Axial skeleton?
Appendicular skeleton?
axial = Bones that are along axis of the body
- skull, sternum, rib, spine
appendicular = bones of appendages
- arms and legs that connect to the axial
- clavicle, scapula, Humerus, pelvis, femur, tibia
Bone
= made up of
- organic materials –> cell and its products (30%) and
70% mineral
- gravity compresses bone
5 types of bones
- Long (greater length than width)
- short (cube shaped)
- flat (thin layers of parallel)
- irregular (e.g. vertebra)
- sesamoid
OSTEO = refers to bone
Cells in bones (3)
- Osteoblasts = build bone
- bone forming
- active near bone surface
- produce collagen
- forms a framework around which bone is boult
- allows bone to flex - Osteocytes = maintain bone
- located in bone matrix
- osteoblasts that have been trapped in bone
- Osteoclasts = break down bone
- remove bone during repair and remodelling
Bone minerals
= give bone compressional strength
Cortical bone = makes up the outer shell of bone giving it shape
Spongy bone = located in ends of bone between the cortical and medullary cavity
- contributes to the length
Bone formation = ossification
Forms in four situations
1. Embryological and foetal development
- When bone grows before adulthood
- Bone remodels (ongoing)
- Fractures heal
The phases of remodelling (3)
= existing bone is resorbed and new bone is laid down
Phase 1: stimulate such as hormone, drugs, physical stress stimulates osteoclasts
phase 2: osteoclasts reabsorb bone leaving behind resorption cavity (2 weeks)
Phase 3: osteoblasts lining the resorption cavity lay down new bone (4 months)
Joints
= connects between bones in the body linking the skeleton into a functional unit
- there are several types of joints and their structure reflects their function
Types of joints
Fibrous = non movement or limited
- bones held together by fibrous
- structures in skill
Cartilaginous = no movement or limited
- pelvic symphysis
Synovial = free movement
- bones are held together by joint capsule and ligaments
- bones not in direct contact
- capsule contains synovium to reduce friction and absorbs shock
- tendon sheaths
Muscles
= generate tension by shortening
- shortening is an active process requiring ATP
Microcytes = cells of the muscles
- electrically excitable, contractile, extend elastic
Types of muscles
Skeletal - attached to skeleton –> responsible for movement
Cardiac - myocardium (in heart)
- responsible for pumping blood
- involuntary
Smooth - located in tissue
- controlling diameter of structures
What happens when muscles contract?
- a chemical energy is transformed into mechanical energy
Made up of fibres that contain contractile proteins (filaments):
- Myosin - think filaments
- heads that project towards actin - Actin - thin filament
- actin has binding sites for myosin head - Brain sends action potential along the motor neuron opening up sodium channels
- Sarcoplasmic reticulum releases calcium into the muscle cells
- calcium rushes into cells allowing for tropine and tropomysion bind to calcium and the protein changes shape (body guard)
- Myosin heads (atp attached) form a cross bridge to actin pulling it across
- therefore muscles have contracted
- when myosin head link to actin form cross-bridges
- cross bridges rotate = muscle contracts
- requires ATP
- once myosin head rotates the connection is broken
muscles relax when cross bridges dont rotate
Skeletal muscles
- Tropmyosin blocks the binding sites on actin and prevents cross bridges from forming
- calcium moves tropomyosin out of the way to allow cross bridges to form
- electrical excitation of muscle cell releases calcium
Fibre types
Distribution of fibre types in a muscle is affected by genetics and training.
Type 1: slow twitch/ red
- contract slowly but fatigue slowly
- use aerobic metabolism to generate ATP
- supplied by nerves that activate them during contraction
- needs lots of O2
Type 2: Fast twitch/ white
- contract quickly but fatigue quickly
- lower capillary needed
- use aerobic metabolism to generate ATP
motor units
= a muscle has many groups of cells that are all supplied by one nerve - cells form motor unit
- increase force of muscle by activating more motor units simultaneously
Tendons
= form link between muscle and bone
- made of collagen
- arrangements of collagen fibres gives tendons their function
