Anatomy & Physiology Study Guide: Cardiovascular, Blood Vessels, Respiratory, Urinary, Digestive, and Reproductive Systems

Cardiovascular System

Heart Anatomy and Blood Flow

The heart is a muscular organ responsible for pumping blood throughout the body via the pulmonary and systemic circuits. Understanding its structure and the flow of blood is essential for comprehending cardiovascular physiology.

• Chambers: Right atrium, Right ventricle, Left atrium, Left ventricle

• Major Vessels: Superior vena cava (SVC), Inferior vena cava (IVC), Pulmonary trunk, Pulmonary veins, Aorta

• Valves: Tricuspid valve, Pulmonary valve, Bicuspid (mitral) valve, Aortic valve

Blood Flow Sequence:

1. Body → SVC/IVC → Right atrium

2. Right atrium → Tricuspid valve → Right ventricle

3. Right ventricle → Pulmonary valve → Pulmonary trunk → Lungs (pulmonary circuit)

4. Lungs → Pulmonary veins → Left atrium

5. Left atrium → Mitral valve → Left ventricle

6. Left ventricle → Aortic valve → Aorta → Body (systemic circuit)

Oxygenation:

• Deoxygenated blood: Body → Right side of heart → Lungs

• Oxygenated blood: Lungs → Left side of heart → Body

Coronary Circulation

The heart receives its own blood supply via the coronary arteries. This circulation is vital for the myocardium's function.

• Left ventricle → Aorta → Coronary arteries → Myocardium

• Cardiac veins → Coronary sinus → Right atrium

Blood Vessels

Arterial and Venous Blood Flow

Blood vessels transport blood to and from the heart, supplying organs and tissues with nutrients and oxygen, and removing waste products.

Arterial Blood Flow: Heart to Upper Body

1. Left ventricle → Aorta → Aortic arch

2. Aortic arch branches:

   • Brachiocephalic trunk (right side)

   • Left common carotid

   • Left subclavian

3. Continue to head/arm: Axillary, Brachial, Radial/Ulnar arteries

Arterial Blood Flow: Heart to Lower Body

1. Left ventricle → Aorta → Descending (abdominal) aorta

2. Common iliac → External iliac → Femoral → Popliteal → Anterior/Posterior tibial arteries

Venous Blood Flow: Upper Body to Heart

1. Radial/Ulnar, Medial cubital, Brachial, Axillary veins → Jugular/Subclavian veins

2. Brachiocephalic veins → Superior vena cava (SVC) → Right atrium

Venous Blood Flow: Lower Body to Heart

1. Tibial → Popliteal → Femoral → External iliac → Common iliac veins

2. Inferior vena cava (IVC) → Right atrium

Respiratory System

Structure and Function

The respiratory system enables gas exchange between the body and the environment. Its structures conduct air and facilitate oxygen and carbon dioxide movement.

• Structures: Nose/nasal cavity, Pharynx, Larynx, Trachea, Bronchi, Respiratory bronchioles, Alveoli

Airflow Pathway

1. Nose → Pharynx → Larynx → Trachea → Bronchi → Bronchioles → Alveoli

Oxygen Pathway (Air to Body)

1. Air → Alveoli → Pulmonary capillaries → Pulmonary veins → Left atrium → Left ventricle → Aorta → Arteries → Tissues

Carbon Dioxide Pathway (Body to Lungs)

1. Tissues → Veins → Right atrium → Right ventricle → Pulmonary trunk → Lungs → Pulmonary capillaries → Alveoli → Bronchioles → Bronchi → Trachea → Out

Urinary System

Structure and Function

The urinary system removes waste products from the blood and regulates fluid and electrolyte balance. Its main structures filter blood and produce urine.

• Structures: Kidneys, Ureters, Urinary bladder, Urethra

Nephron Anatomy

• Glomerulus

• Glomerular (Bowman's) capsule

• Proximal convoluted tubule (PCT)

• Loop of Henle

• Distal convoluted tubule (DCT)

• Collecting duct

Filtrate Pathway

1. Glomerulus → Glomerular capsule → PCT → Loop of Henle → DCT → Collecting duct

2. Minor calyx → Major calyx → Renal pelvis → Ureter → Bladder → Urethra → Out

Digestive System

Structure and Function

The digestive system breaks down food, absorbs nutrients, and eliminates waste. Its organs are specialized for different stages of digestion.

• Structures: Mouth, Pharynx, Esophagus, Stomach, Small intestine (duodenum, jejunum, ileum), Large intestine (cecum, colon sections, rectum), Anus, Liver, Pancreas

Food Pathway

1. Mouth → Pharynx → Esophagus → Cardiac (LES) sphincter → Stomach → Pyloric sphincter → Duodenum → Jejunum → Ileum → Ileocecal valve → Cecum → Ascending colon → Transverse colon → Descending colon → Sigmoid colon → Rectum → Anus

Reproductive System

Structure and Function

The reproductive system is responsible for producing gametes and facilitating fertilization. It includes distinct male and female structures.

Sperm Pathway (Male)

1. Testis → Epididymis → Vas deferens → Ejaculatory duct → Urethra → Out

Ovum Pathway (Female)

1. Ovary → Uterine tube (fallopian tube) → Uterus → Cervix → Vagina → Out

Major Reproductive Structures

Male	Female
Testis	Ovary
Epididymis	Uterine tube
Vas deferens	Uterus
Urethra	Cervix
Penis	Vagina

Additional info:

• Principle of complementarity: Structure and function are interrelated at all levels, from cells to organ systems.

• Histology: Identification of tissues and organs under the microscope is essential for understanding function.

• Clinical relevance: Knowledge of pathways and structures is foundational for diagnosis and treatment in health professions.