Visceral system Flashcards

1
Q

Cardiovascular System

A

Major structural components of the CVD system:
- Blood vessels
Arteries: carry blood away from the heart (mostly oxygenated blood)
Capillaries: Supply blood cells with nutrients and oxygen and take waste products away
Veins: Return blood to the heart (most deoxygenated blood)
- Heart: a muscular organ that pumps blood through blood vessels
- Blood: Is a fluid connective tissue that is transported in the CV system

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2
Q

The heart

A

The heart functions as a dual pump system: A muscular wall called the septum separates the left and the right sides of the heart
- The right heart deals with oxygen: poor blood and is low-pressure system (pulmonary circuit)
- The left heart deals with oxygen-rich blood and is high-pressure system (systemic circuit)

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3
Q

Location and orientation within the thorax

A
  • First sized, cone-shaped organ
  • Located left of the body midline; posterior to the sternum in the mediastinum
  • Obliquely oriented, apex is inferior
  • The right side is located more posteriorly
  • The heart is located within the mediastinum
    Mediastinum: is a space between the sternum, the vertebral column, the lungs and the diaphragm
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4
Q

Structure of the heart

A

Pericardium: Triple-layered sac that encloses the heart
- Fibrous pericardium: Outer, strong layer of dense connective tissue. Attached to the diaphragm inferiorly and vessels of the heart superiorly
Serous pericardium: 2 layers
- parietal layer= outer
- Visceral layer (epicardium)- directly covers the heart
- Pericardial cavity: between the 2 layers and contain fluid film to reduce friction

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5
Q

Layers of the heart wall: 3 layers

A
  1. Epicardium: Consists of visceral serous pericardium
  2. Myocardium: Cardiac muscle tissue, contractile layer
  3. Endocardium: Deep to myocardium, sheet of simple squamous epithelium on a thin layer connective tissue (lines chambers and valves)
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6
Q

Myocardium

A
  • Small branched cells: 25 cm wide: 120 cm long
  • contains myofibrils and sarcomeres (striated)
  • Cardiac cells are interconnected at junctions called intercalated discs
  • Spontaneously contracts- without neural input
  • Innervated by autonomic nervous system
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7
Q

Internal heart anatomy

A

Atria are separated from each other by interatrial septa: and ventricles by interventricular septa.
Within the septa is the fibrous skeleton of the heart which has these functions:
- Anchors heart valves by forming supportive rings
- Provides a rigid framework for the attachment of cardiac muscle tissue in atria and ventricles
- Electrical insulation between atria and ventricles: ensures that muscle impulses are timed properly

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8
Q

Papillary muscles

A

Papillary muscles and chordae tendineae present the values from being pushed to the atria
- Papillary muscles are relaxed and chordae tendineae slack when bicuspid and tricuspid valve are open
- Papillary muscles are contracted and chordae tendineae taut when bicuspid and tricuspid valves are open

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9
Q

Right atrium

A
  • Receives deoxygenated blood from systemic circulation via 3 blood vessels
  • Conveys blood into the right ventricle through the tricuspid valve
  • Contains the SA and AV nodes
  • Important internal feature: fossa ovalis
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10
Q
  • Receives deoxygenated blood from systemic circulation via 3 blood vessels
  • Conveys blood into the right ventricle through the tricuspid valve
  • Contains the SA and AV nodes
  • Important internal feature: fossa ovalis
A
  • Receives deoxygenated blood from the right atrium and pumps it into the pulmonary circuit through the pulmonary
  • Trunk via the pulmonary semilunar valve
  • Important internal features: trabecular carneae line the walls of both ventricles
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11
Q

Left atrium and ventricle

A
  • Receives oxygenated blood from pulmonary circulation via 4 pulmonary veins (2 left and 2 right)
  • Separated from the left ventricle by bicuspid (mitral valve)
  • Important internal features: auricle contains pectinate muscles
    V
  • Forms the apex of the heart
  • Pumps blood into the systemic circuit through the aortic semilunar valve into the aorta
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12
Q

Flow is uni-directional

A

Pulmonary circuit
- Pumps blood from the right side of the heart through pulmonary vessels, to the lungs and back to the left side of the heart
Systemic circuit
- Pumps blood from the left side of the heart through systemic vessels in peripheral tissues and back to the right side of the heart

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13
Q

Heart blood supply

A
  • The heart has 3 major sulci (grooves) that separate the 4 chambers and major coronary blood vessels occupy these sulci
  • Atrioventricular and interventricular grooves contain adipose tissue and coronary blood vessels
  • Fat depot in epicardium surrounds and cushions coronary blood vessels
  • Increased epicardial adipose tissue is, however, viewed as a cardiac risk marker
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14
Q

Coronary arteries of the heart

A
  • Coronary arteries originate from the base of the aorta
  • Coronary arteries supply oxygen and nutrients to the heart muscles and coronary veins drain the blood
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15
Q

Coronary veins

A
  • The coronary sinus is the biggest cardiac vein which ultimately collects the blood from all cardiac veins and drains the blood into the right atrium
  • Coronary sinus, great and small cardiac veins are located in the coronary groove
  • Middle cardiac vein is located in posterior interventricular groove
  • Great cardiac vein primarily drains the left heart, the small cardiac vein drains the right heart and the middle cardiac vein drains the interventricular septum
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16
Q

Atrial Fibrillation

A
  • Irregular and rapid heart beat caused by extra electrical impulses disrupting SA node activity
  • Result in chaotic atrial contractions at faster rate than ventricles
  • Diagnosis: ECG
  • Treatments: ECG, catheter ablation, pacemaker
17
Q

Hepatic portal system

A

The hepatic portal system is a network of veins that carries venous blood from the gastrointestinal tract and spleen to the liver before it returns to the inferior vena cava and the heart.
The liver receives 2 blood supplies:
-The hepatic portal veins contain oxygen-poor but nutrient-rich blood, drains only unpaired organs
- The hepatic artery proper contains oxygen rich blood

18
Q

Veins of the lower limb

A

Deep veins
- Medial plantar veins drain into posterior tibial veins
- Fibula veins drain into the posterior tibial veins
- Tibial veins merge to form the popliteal veins which becomes the femoral vein and then the external iliac vein
- External and internal iliac veins unite into the common iliac vein
- The common iliac veins merge to form the inferior vena cava
Superficial veins
- Dorsal venous arch drains into and great saphenous veins and small saphenous vein
- Great saphenous drains into femoral vein
- Small saphenous drains into popliteal

19
Q

Boyle’s law

A

The pressure of a gas decrease if the volume of the container increase and vice versa.
Inhalation: increasing volume of the thoracic cavity decreases intrapulmonary pressure relative to the atmospheric pressure and air flows into the lungs
During inhalation,
- The lungs expand
- The pressure in the lung’s decreases
- Air flows towards the lower pressure in the lungs
Exhalation= Volume of the thoracic cavity decreases, pressure rises relative to outside atmospheric pressure air is forced out of the lungs
During an exhalation
- Lung volume decreases
- Pressures within the lungs increases
- Air flows from the higher pressure in the lungs to the outside

20
Q

Disorders of the Respiratory system

A

Bronchial asthma= allergic inflammatory response causes bronchoconstriction
Cystic fibrosis: Accumulation of mucous, clogs the respiratory system and causes bacterial infection
Chronic bronchitis: Inhaled irritants lead to excess mucous, inflammation and fibrosis- impairing ventilation and gas exchange
Emphysema Permanent enlargement of alveoli due to inc. lysosomes destroying alveolar walls; lungs become less elastic