Cardiovascular System
-
Upload
jaya-pragasam -
Category
Documents
-
view
217 -
download
3
Transcript of Cardiovascular System
The cardiovascular system
Structure of the heart
The cardiac cycle
Structure and organization of blood vessels
What is the cardiovascular system?
The heart is a double pump
heartarteries arterioles veinsvenules capillaries
Fungsi sistem kardiovaskular
Penghantar-Menghantar oksigen dan nutrient ke setiap sel di dalam badan melalui darah yang dipam oleh jantung.
Pengeluar-mengeluarkan karbon dioksida dan sisa hasil metabolism daripada setiap sel dalam badan.
Pengangkut-mengangkut hormone dari kelenjar endokrin ke sel-sel sasaran melalui plasma darah.
Pengekal-membantu mengekalkan suhu dalam badan.
Penghalang-menghalang dehidrasi dan infeksi dengan mengekalkan tahap cecair pada kadar yang sesuai.
Blood supply to the heart
Coronary artery and vein system
Right and left coronary arteries branch off ofaorta
Branch into smaller vessels
Cardiac veins deliver blood to coronary sinus,and back to the right atrium
Coronary artery disease results when coronaryarteries cannot deliver blood adequately
Usual cause: plaques in arterial walls
Angina pectoris (pain) when body is notreceiving adequate oxygen
Myocardial infarction (heart attack) whenblood supply to heart is completelyblocked; muscle dies
Conduction system of the heart
Heart contracts as a unit
Atrial and ventricular syncytia help conductelectrical signals through the heart
Sinoatrial (S-A) node is continuous with atrialsyncytium
S-A node cells can initiate impulses on theirown; activity is rhythmic
Regulation of heart rate
Blood pressure and its control
What is hypertension and how is it treated?
The heart rate and exercise
Characteristics of arteries and veins
Organization of the vascular system andresponses to physiological needs
Regulation of the cardiac cycle
Sympathetic and parasympathetic nervoussystems
Parasympathetic: from medulla oblongata(vagus nerve)
Nerve branches to S-A and A-V nodes, andsecretes acetylcholine (slows rate)
Parasympathetic activity can increase (slowheart rate) or decrease (increase heartrate)
Sympathetic nervous systemthrough celiac plexus to heartsecretes norepinephrineincreases force of contractions
Cardiac control center in medulla oblongatamaintains balance between the two
Normally both sympathetic and parasympatheticfunction at a steady background level
Blood pressure
Blood flow is generally equal to cardiac output
Blood flow affected by pressure and resistance
Blood pressure: the force that is exerted by bloodagainst blood vessel walls
Resistance depends on size of blood vessel andthickness (viscosity) of blood