Quiz on Digestive System Anatomy

Digestive System

• Esophagus: 25 cm long

• Begins in the neck, enters the thoracic cavity, and ends in the cardiac end of the stomach

• Parts: short cervical part, long thoracic part, very short abdominal part

• Stomach: Important organ

• Parts: cardiac, fundus + body, pyloric (antrum + canal + pylorus)

• The cardiac end is where the esophagus ends

• The pyloric end is where the duodenum begins

• Curvatures:

  • Lesser curvature (right border)
  • Greater curvature (left border)

• Surfaces: anterior and posterior

• Position: on the side of the abdominal cavity, behind the liver lobe

• Shape: J-shaped when empty

Small Intestine

• Parts: duodenum, jejunum, ileum

Large Intestine

• Parts: caecum/vermiform appendix/ascending colon/right colic/flexure/transverse colon/left colic flexure/descending colon/pelvic colon/rectum/anal canal
• Characteristics: taenia coli, appendices epiploicae, sacculations

Liver

• Weight: 1.5 kg
• Shape: large wedge-shaped
• Position: upper right part of the abdominal cavity, below the diaphragm
• Function: storage and concentration of bile
• Number of lobes: 2 (large right lobe + small left lobe)

Pancreas

• Length: 12-15 cm
• Position: posterior wall of the abdomen, extending from the duodenum on the right to the spleen on the left
• Parts: head, neck, body, tail
• Function:
  • Endocrine: secretes hormones that regulate blood glucose levels (insulin lowers, glucagon elevates)
  • Exocrine: secretes pancreatic enzymes that aid in digestion

Cardiovascular System

• Heart Chambers: right atrium/right ventricle, left atrium/left ventricle
• Valves: Tricuspid valve – pulmonary valve, mitral valve – aortic valve
• Veins: superior vena cava, inferior vena cava, right pulmonary veins, left pulmonary veins
• Arteries: aorta, left Pulmonary artery, right Pulmonary artery

Respiratory System

• Larynx: Tube shaped
• Formation: 9 cartilages (3 single + 3 paired) - thyroid, cricoid, epiglottis
• Position: from the root of the tongue to the beginning of the trachea
• Function: passage of air to trachea and lungs, production of voice, reflex expulsion of foreign bodies

Trachea

• Length: 10 cm
• Forming: 16-20 C-shaped cartilages
• Position: upper half in neck, lower half in thorax, ends in thorax behind sternal angle, branches into two bronchi
• Function: transmits air from larynx to lungs

Lungs

• Shape: half-cone shaped, apex above and base below
• Structure: 2 surfaces (lateral convex + medial concave), covred by pleura (visceral and parietal) with pleural cavity in-between
• Difference: Right lung is short and wide (625g, three lobes, two fissures, 10 segments, no cardiac notch); Left lung is long and narrow (565g, two lobes, one fissure, 8 segments, has cardiac notch)

Endocrine System

• Pituitary gland: Weight: 1/2 gm, position: middle part of the base of the skull, below the brain
• Thyroid Gland: Position: front of lower part of the larynx, upper part of trachea, lower part of the neck, Shape : Butterfly Secretes: thyroxine
• Parathyroid glands: 4 yellow glands, Position: posterior surface of the thyroid gland, Secretes: parathyroid hormone, Function: regulates calcium and phosphorus metabolism.
• Suprarenal glands (Adrenals): Shape: Two semilunar/triangular, Position: upper poles of the kidneys, Formation: Cortex and medulla, Secretes: Cortex (cortisone and aldosterone hormones), Medulla (adrenaline and noradrenaline hormones)
• Pancreas: endocrine and exocrine gland, Position: lies transversely on the posterior abdominal wall extending from the duodenum till the spleen; Secretes: insulin and glucagon (endocrine), enzymes (exocrine)
• Gonads: Testes (male) secretes testosterone, Ovaries (female) secretes estrogen and progesterone

Urinary System

• Kidney: Position: upper part of the posterior abdominal wall, from the last rib to the level of L3 vertebra. Shape: bean shaped, Structure: 2 ends (upper and lower), 2 margins (lateral convex and medial concave containing hilum), 2 surfaces (anterior and posterior), Size: 12 x 6 x 3 cm
• Ureter: Shape: muscular tube, Length: 25 cm, Position: from the hilum of the kidney to the urinary bladder, Structure: sites of narrowing or constrictions at its beginning, Function: transmitting urine
• Urinary Bladder: Shape: pyramidal shape when empty, Position: present inside the pelvic cavity behind the symphysis pubis, Function: reservoir of urine, receives the 2 ureters, urine leaves through the urethra
• Urethra: Function: carries urine to outside the body.
• Difference between male and female urethra: Male (20 cm - prostatic, penile, membranous); Female (4 cm - short and wide tube, anterior wall of vagina).