The Heart and Blood - Details

Levels:

1) Chapter 1 View

Questions:

64 questions

🇬🇧		🇬🇧

Is an organic chemical that functions in the brain and as a neurotransmitter

Acetylcholine (Ach)

Is the main artery that carries blood away from your heart to the rest of your body.

Aorta

The layers in the arteriole; tunica externa (connective tissue); Tunica media (smooth muscle cells); Tunica Intima (endothelial cells).

Arteriolar tone

A small branch of an artery leading into capillaries. Has muscles for vasoconstriction/dilation, can control where blood is distributed. Relax and contract in response to blood flow. Small diameter with smooth muscle. Greatest change in blood pressure.

Arteriole

Is a part of the electrical conduction system of the heart that coordinates the top of the heart. It electrically connects the atria and ventricles.

Atrioventricular node or AV node

Valves between the atrium and ventricle: tricuspid and mitral valves. Attached to ventricle wall Chordae Tendineae

Atrioventricular valve

Is needed to deliver oxygen and nutrients to the cells. It also removes cell waste products.

Blood flow

Distribution (oxygen, waste, hormones); Regulation (body temperature, pH, fluid); Protection (preventing blood loss and infection)

Blood Functions

L 120/80 (Sys/Dys)

Blood Pressure- Norma

Beats per minute

BPM

Slow of irregular heart rhythm, usually fewer than 60bpm

Bradycardia

Cardiac muscle fibres that conducts the electrical impulses that regulate the heartbeat, from the atrioventricular node in the right atrium to the septum between the ventricles and then to the left and right ventricles.

Bundle of His

Amount of blood the heart pumps in 1 minute. Q (L/min)= Stroke volume x heart rate. Decides the rate of blood flow to parts of the body.

Cardiac Output (Q)

Are the cells responsible for generating contractile force in the intact heart

Cardiomyocytes

A group of tough, tendinous strands in the heart. They are commonly referred to as the “heart strings” since they resemble small pieces of string. Tether atrioventricular valves to ventricle.

Chordae Tendineae

SA node, AV node, Bundle of His and Purkinje fibres. Depolarisation of the cells of the heart lead to contraction via the hearts conduction system.

Conduction System in the heart

Supply the heart with blood

Coronary Vessels (veins and arteries)

Relaxation of the heart. Normal 80mmHg.

Diastolic Pressure

An electrocardiogram is a test which measures the electrical activity of your heart to show whether it is working normally. It records when the atria and ventricles contract/depolarise (become more positive) and relax/repolarise (become more negative).

ECG

Red blood cells. Red due to carrying oxyhaemoglobin. Shape allows them to be flexible and stack.

Erythrocytes

Between 60-100 bpm. Women’s hearts beat faster than men.

Heart rate- normal

Controlled by parasympathetic and sympathetic nervous systems.

Heart rate regulation

High blood pressure.>140/>90

Hypertension

Low blood pressure <90/<60

Hypotension

Is a large vein that carries the deoxygenated blood from the lower and middle body into the right atrium of the heart.

Inferior vena cava (or IVC)

Wall between the ventricles

Intraventricular septum

The sounds heard via a stethoscope when using a sphygmometer that indicated systolic and diastolic pressure (sharp tapping at systolic pressure; tap followed by wooshing; crisp tap; dull thudding and silence at diastole pressure ).

Korotkoff sounds

White blood cells. Involved in counteracting foreign substances and disease

Leukocytes

The “ lub” is the first heart sound, commonly termed S1, and is caused by turbulence caused by the closure of mitral and tricuspid valves at the start of systole. The second sound,” dub” or S2, is caused by the closure of aortic and pulmonic valves, marking the end of systole.

Lub Dub

Important for defence against viruses and chronic infections

Macrophages

Diastolic pressure+ (pulse pressure/3)= average pressure across cardiac cycle.

Mean arterial pressure

The valve between the left atrium and the left ventricle of the heart, which has two tapered cusps.

Mitral Valve

Are a type of white blood cell; they transform into macrophages when they leave the blood stream

Monocytes

Any of the elongated contractile threads found in striated muscle cells

Myofibrils

Acts as a vasodilator

Nitrous Oxide

A hormone which is released by the adrenal medulla and by the sympathetic nerves and functions as a neurotransmitter. It is also used as a drug to raise blood pressure

Noradrenaline

Concentrated in the Sinoatrial Node (SA) set the rhythm of the heartbeat. Located in right atria. Main generator of electrical impulse.

Pacemaker cells

Are muscles located in the ventricles of the heart

Papillary muscles

Is one of three divisions of the autonomic nervous system. Sometimes called the rest and digest system, the parasympathetic system conserves energy as it slows the heart rate, increases intestinal and gland activity, and relaxes sphincter muscles in the gastrointestinal tract.

Parasympathetic nervous system

Between 7.35 and 7.45

Plasma Ph

A small colourless disc-shaped cell fragment without a nucleus, found in large numbers in blood and involved in clotting.

Platelets

Carries deoxygenated blood from the right ventricle to the lungs

Pulmonary artery

Originates from the right ventricle of the heart and carries deoxyhaemoglobin to the lungs. Returns oxyhaemoglobin to the left atrium of the heart (heart to lungs).

Pulmonary Circulation

(or pulmonic valve) is the semilunar valve of the heart that lies between the right ventricle and the pulmonary artery and has three cusps.

Pulmonary valve

Systolic pressure – diastolic pressure

Pulse pressure

Are specialised conducting fibres composed of electrically excitable cells that are larger than cardiomyocytes with fewer myofibrils and many mitochondria and which (cells) conduct cardiac action potentials more quickly and efficiently than any other cells in the heart.

Purkinje fibres

Shaped like a half-moon or crescent

Semilunar

Is a specialized myocardial structure that initiates the electrical impulses to stimulate contraction, and is found in the atrial wall at the junction of superior caval vein and the right atrium

Sinoatrial node (SA node)

Heart rate greater than 100bpm but a normal rhythm.

Sinus Tachycardia

Used to measure blood pressure

Sphygmomanometer

Amount of blood the heart pumps in one beat (in ml). Average around 80ml.

Stroke Volume

Is the superior of the two venae cavae, the great venous trunks that return deoxygenated blood from the systemic circulation to the right atrium of the heart

Superior vena cava (SVC)

Directs the body's rapid involuntary response to dangerous or stressful situations. Exercise and stimulants increase Sympathetic activity.

Sympathetic Nervous Systems

Originates from the left of the heart and carries oxyhaemoglobin to the periphery (all body tissues). Returns oxyhaemoglobin to the right atrium of the heart.

Systematic Circulation

Contraction of the heart. Normal 120mmHg

Systolic Pressure

Is one of the two main valves on the right side of your heart. Normally, the tricuspid valve has three flaps (leaflets) that open and close, allowing blood to flow from the right atrium to the right ventricle in your heart and preventing blood from flowing backward.

Tricuspid valve

Connective tissue

Tunica Externa

Endothelial cells

Tunica intima

Smooth muscle cells

Tunica media

HEART> Aorta>Arteries>Arterioles>Systematic Capillaries (gas diffusion)>venules>veins>Superior and inferior vena cava> HEART

Vascular System

Causes narrowing of the blood vessels

Vasoconstrictor

When the circular smooth muscle in the arteriole contracts leading to increased resistance and decreased blood floe

Vasocontraction

Decreased contraction of circular muscle in arteriole which leads to decreased resistance and increased blood flow

Vasodilation

Causes widening of the blood vessels

Vasodilator

The Heart and Blood

Practice Known Questions

Exams

Learn New Questions

The Heart and Blood - Leaderboard