Studied by 55 people
Heart
Delivers oxygen
Delivers heat to the surface of the skin
Removes the waste products in the body
Route taken by blood
RVAVAVAL
Chambers of the heart
Right atrium, right ventricle, left ventricle left atrium separated by the septum
Size and strength of chambers
Atriums have thin muscle walls
Ventricles have thick walls
Left side of the heart is larger
Name and location of valves
Bicuspid separates left atrium and ventricle
Tricuspid separates right atrium and ventricle
Semi lunar valves separate ventricles and arteries
Chordae Tendineae
Strong fibrous strings that attach heart muscles to the valves. They serve to anchor the valves and not let them close
Cardiac Conduction system
A group of specialised cells located in the wall of the heart which send electrical impulses to the cardiac muscle, causing it to contract.
SAN
Sino atrial node
Begins the wave of excitation
Myogenic
Capacity of the heart to generate its own impulses
What is the impulse described as
Wave of excitation
AVN
Atrio ventricular node
Delays the wave of excitation to limit the increase of the Heart rate
Systole and diastole
Heart pumping and the heart filling respectively
What follows the AVN
Bundles of HIS, splitting into bundle branches
What follows bundle of HIS
Purkinje fibres, these spread the impulses around the ventricles and cause them to contract
Neural Control system
Central nervous system
Peripheral nervous system
Autonomic nervous system
CNS
Brain
Retina
Spinal cord
Command centre of the body
Peripheral nervous system
Nerves that connect the CNS to the arms and legs
Autonomic nervous system
Nerves that connect the CNS to organs
What is the autonomic nervous system split into
Sympathetic and Parasympathetic
Sympathetic
A part of the nervous system that speed up heart rate and prepares the body for exercise
Parasympathetic
Decreases heart rate and returns the body to a resting state after exercise
Medulla Oblongata
Cardiac Control Centre
Responsible for autonomic nervous functions
What is the medulla oblongata stimulated by
Chemoreceptors
Baroreceptors
Proprioceptors
Chemoreceptors
Detect changes in the acidity and chemicals in the bloodstream
Increase in CO2 = increase in heart rate
Baroreceptors
Detect changes in blood pressure
Increase in blood pressure= decrease in HR
Proprioceptors
Detect changes in muscle movement and tension
Increase muscle movement = Increases HR
Hormonal Control System
Adrenaline is released from the adrenal glands and mimicks the sympathetic nervous system increasing heart rate before exercise
Stroke volume
The volume of blood pumped by the ventricles for each contraction
Ejection fraction
The percentage of blood pumped out by the left ventricles per beat
cardiac output
stroke volume x heart rate
Venous return
Amount of blood returning to the lungs via the veins
Starlings law
Increased venous return, increased diastolic filling, cardiac muscle is stretched, more force of contraction, increased ejection fraction
Myocardium
Cardiac tissue
Cardiac hypertrophy
The thickening of the muscular wall of the heart so it becomes stronger
Bradycardia
A decrease in resting heart rate below 60bpm
Coronary Heart Disease
Coronary arteries are blocked and lumen is narrow reducing blood flow
Atherosclerosis/ atheroma
The process of fatty build ups being deposited in the vessels. Atheroma is the fatty deposits
Angina
Chest pain when the coronary arteries are blocked enough to cause pain
Blood Pressure
The force exerted by the blood on the walls of the blood vessels
Cholesterol (LDL)
Low density lipoproteins
Transports cholesterol to the blood vessels. Considered the bad ones as linked to heart disease
Cholesterol (HDL)
High density lipoproteins
Transport atheroma back to the liver where it is broken down. Considered the good ones as they lower the risk of CHD
Ishaemic stroke
The most common. Occur when a blood clot stops blood supply
Haemorrhagic Strokes
occur when a weakened blood vessels supplying the brain bursts
Cardiovascular drift
Heart rate increases
Stroke volume decreases
Fluid is lost as sweat
Reduced plasma volume
Reduced venous return
Cardiac output also increases due to more energy needed to cool the body
5 different types of blood vessels
Arteries
Arteriols
Capillaries
Venules
Veins
Veins
Thinner muscle/ elastic tissue
Blood is at low pressure
Valves
Wider lumen
Arteries
Thick muscle and elastic tissue
Small lumen
High blood pressure as they carry blood away from the heart
Capillaries
One cells thick
Short diffusion path for oxygen and Co2
Very low blood pressure
Systemic blood pressure
Pressure of the oxygenated blood travelling to the body
The pressure in the arteries when the heart is contracting
Diastolic blood pressure
The pressure of the deoxygenated blood travelling from the heart to the lungs
The pressure in the arteries when the ventricles are relaxing
Where is blood pressure measured from
The brachial artery in the upper arm
What is a healthy blood pressure
120/80
Three mechanisms for venous return
Skeletal muscle pump
Respiratory pump
Pocket valves
Skeletal muscle pump
The muscles contracting and changing shape resulting in veins to change shape and squeeze the blood back to the heart
Respiratory pump
The pressure changes in the thoracic and abdominal cavities during breathing and will therefore compress the nearby veins and push blood back to the heart
Pocket valves
These valves prevent the back flow of blood in the veins
Equation for blood pressure
Blood flow x resistance
What is venous return determined by
Pressure gradient
Mean systemic pressure
The mean pressure that exists in the circulatory system when the heart has had a chance to evenly redistribute blood to all vessels and organs
Peripheral veins
Lead deoxygenated blood from the capillaries back to the heart
Vascular resistance
The resistance that must be overcome for the blood to be pushed around the circulatory system
Haemoglobin
An iron-containing pigment found in red blood cells, which combines with oxygen to form oxyhaemoglobin
Myoglobin
Often known as muscles haemoglobin
Stores the oxygen in the muscles to be used during longer activities
Mitochondria
Site for aerobic respirations and is the powerhouse of the cell
High affinity for oxygen
Need lots of oxygen to operate
What is the name for the translation of the curve in the positive x direction
BOHR shift
What factors impact the BOHR shift
Increased temperature
Increased partial pressure of CO2
Lower pH (increased acidity)
What is the redirecting of blood to the areas that need it called?
Vascular shunt mechanism
What happens to the blood during vigorous exercise as a result of a vascular shunt?
Blood is distributed away from digestive organs and travels to the working muscles.
Pre capillary sphincters
Rings of tissue at the start of the blood vessel. When contracting, they block of the proceeding vessel and there is limited blood flow to the areas that vessel supplies.When they contract blood flow is blocked.
Vasodilations and Vasoconstriction
Dilation- the widening of the lumen to allow more blood flow. This also pushes the vessel closer to the surface to allow for heat to leave the body
Constriction- Vessels decrease lumen diameter and go deeper into the skin resulting in a conservation of heat
Why is blood distribution important? (4 things)
Increase supply of oxygen
Remove lactic acid and other waste products
Regulation of body temperature
Direct more blood to the heart
Atrio-venous difference
The difference between the content of oxygen of the arterial blood arriving at the muscles and the venous blood leaving the muscles
At rest, what is the AVO2 like
Low as not much oxygen is required at the muscles
What is the equation for venous pressure
Venous pressure - Right atrial pressure /Total peripheral vascular resistance
The sections of vertabrae
Cervical, thoracic, lumbar, sacrum, coccyx
Bones in the pelvis
Iliac crest
Ilium
Pubis
ischium
Cervical vertabrae
7 bones
Provides support for the weight of the head and surrounds and protects the spinal cord
Thoracic vertabrae
12 vertabrae
Provides attachment point for multiple muscles
Lumbar vertabrae
5 vertabrae
Provides stability for the spinal column and back
Sacrum vertabrae
5 vertabrae
Is fused to the coccyx and is responsible for strengthening the pelvis
Coccyx
4 vertabrae
Fused to sacrum and provides weight bearing support when seated also multiple insertion point for muscles and ligament
5 types of bones
Long
Short
Irregular
Flat
Sesamoid
Long bone
Longer than it is wide
Femur, humerus, tibia, fibula
Shaft called diaphysis and ends called epiphysis
Short bone
Cube shaped consisting of cancellous bone surrounded by a layer of compact bone
Carpals, Tarsals, Wrists
Fine or small movements, shock absorption, weight bearing
Flat bone
Thin, flattened and slightly curved, with a large surface area.
Sternum, Cranium
Irregular bone
Mostly protect the spinal cord and allow small amounts of movement
Vertabrae
Sesamoid bones
Have a specialised function
Protection and reduction of friction at a joint
Patella
Ligaments
Strong fibrous tissue
Stabilise the joint, attach bone to bone, prevent any unwanted movement
Fibrous joint
Fixed position
Protects vital organs
Bones overlap and interlock
Cartilaginous joint
Slightly moveable
Bones are separated by fibrocartilage which when compressed, will move bones
Synovial joint
Freely moving
High level of mobility at the joint
Most of e body’s joints are synovial
Functions of the skeletal system (PASS and MOVE)
Protection, Attachment, Blood cell production, Store of minerals, Movement
Neuromuscular system
Nervous system and muscular system work together to allow movement
Three different muscle fibres
1, 2a, 2x
Type 1 muscle fibre
Small and red
Slow force of contraction and speed
Aerobics
High fatigue resistance
High mitochondria and high slow release sugars
Type 2a fibres
Moderate and red
Medium force of contraction and speed
Aerobics
High fatigue resistance
Type 2x fibres
Large and white
High force of contraction and speed
Weight lifting and sprinting
High glucose
Low fatigue resistanace
Motor Unit
A motor neurone and its muscle fibres
Motor neurones
Nerve cells which transmit the brains instructions as electrical impulses to the muscles
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