Visual Pathway
Cornea aqueous humor of anterior segment lens vitreous humor of posterior segment retina (photoreceptors bipolar cells ganglion cells) optic nerve optic chiasm optic tract thalamus (sensory integration center) primary visual cortex (occipital lobe)
Auditory Pathway
Auricle external auditory meatus (canal) tympanic membrane malleus incus stapes oval window auditory hair cells (in spiral organ of Corti in cochlea) cochlear nerve medulla inferior colliculus (auditory reflex center in midbrain) thalamus(sensory integration center) primary auditory cortex (temporal lobe)
Olfactory Pathway
Olfactory receptor cells olfactory nerve olfactory bulb olfactory tracts (two pathways)
1. thalamus olfactory cortex to interpret and identify smells
2. hypothalamus, amygdala, limbic system to elicit emotional responses to odors
Gustatory Pathway
Gustatory hair cells cranial nerves (facial nerve, glossopharyngeal nerve, vagus nerve) medulla oblongata thalamus gustatory cortex (in insula cortex) and hypothalamus, amygdala, limbic system to elicit emotional responses to tastants
Pathway of blood through the heart
Superior & Inferior Vena Cavas and coronary sinus Right atrium Tricuspid valve Right ventricle Pulmonary semilunar valve Pulmonary trunk Pulmonary arteries Lung capillaries Pulmonary veins Left atrium Bicuspid (mitral) valve Left ventricle Aortic semilunar valve Aorta to the systemic arteries systemic capillaries systemic veins superior & inferior vena cavas and coronary sinus
Intrinsic conduction system of the heart
Sinoatrial node (intrinsic pacemaker cells) Atrioventricular node Atrioventricular bundle (Bundle of His) Left and right Bundle branches Purkinje fibers
Pathway of air
Nares Nasal cavity Nasopharynx Oropharynx Laryngopharynx Larynx Trachea Primary Bronchus Secondary Bronchus Tertiary Bronchus Bronchiole Terminal bronchiole Respiratory bronchiole Alveolar duct Alveolus (alveoli)
Upper respiratory tract: Nasal cavity, pharynx and larynx
Lower respiratory tract: Trachea, bronchi, bronchioles, lungs
Pathway of food
Oral cavity Oropharynx Laryngopharynx Upper esophageal sphincter Esophagus Lower esophageal (cardiac) sphincter Stomach Pyloric sphincter Duodenum* Jejunum Ileum Ileocecal valve Cecum** Ascending colon Hepatic flexure Transverse colon Splenic flexure Descending colon Sigmoid colon Rectum Anal canal Anus
* The common bile duct and pancreatic duct enter the duodenum.
** The vermiform appendix is attached to the Cecum.
Small intestine: Duodenum, Jejunum, Ileum
Large intestine: Cecum, Ascending Colon, Transverse Colon, Descending Colon, Sigmoid Colon, Rectum, Anal Canal
Pathway of urine formation
Renal artery Afferent arteriole Glomerulus Bowman's capsule Proximal convoluted tubule Descending limb of Loop of Henle Ascending limb of Loop of Henle Distal convoluted tubule Collecting duct Minor calyx Major calyx Renal pelvis Ureter Bladder Urethra
Pathway of Sperm
Seminiferous tubules Rete testis Epididymis Ductus (vas) deferens Ejaculatory duct
Urethra Vagina Cervix Uterus Uterine (Fallopian) tube (oviduct)