pathways

Visual Pathway

The pathway of light travels through the Cornea → Aqueous Humor → Pupil → Lens → Vitreous Humor → Retina (photoreceptor cells) → Ganglion Cells → Optic Nerve → Optic Chiasm → Lateral Geniculate Nucleus (thalamus) → Primary Visual Cortex.

Auditory Pathway

The pathway of sound travels from the Auricle → External Auditory Canal → Tympanic Membrane → Ossicles (Malleus, Incus, Stapes) → Oval Window → Cochlea (hair cells) → Spiral Ganglion → Auditory Nerve → Brainstem Nuclei → Medial Geniculate Nucleus (thalamus) → Primary Auditory Cortex.

Olfactory Pathway

The pathway for smell travels from Olfactory Receptor Cells → Olfactory Bulb → Olfactory Tracts → Olfactory Cortex (temporal lobe) and other areas including the amygdala and hippocampus.

Gustatory Pathway

The pathway for taste travels from Gustatory Hair Cells → Cranial Nerves (VII, IX, X) → Nucleus of the Solitary Tract (medulla) → Thalamus → Gustatory Cortex.

Pathway of Blood through the Heart

The route is Vena Cavas → Right Atrium → Tricuspid Valve → Right Ventricle → Pulmonary Valve → Pulmonary Arteries → Lungs (oxygenation) → Pulmonary Veins → Left Atrium → Mitral Valve → Left Ventricle → Aortic Valve → Aorta.

Intrinsic Conduction System of the Heart

The rhythmic control travels through Sinoatrial Node (SA Node) → Atrioventricular Node (AV Node) → Bundle of His → Right and Left Bundle Branches → Purkinje Fibers.

Pathway of Air

The route for air is Nares → Nasal Cavity → Pharynx → Larynx → Trachea → Bronchi → Bronchioles → Alveoli (gas exchange).

Pathway of Food

The route food takes: Oral Cavity → Pharynx → Esophagus → Stomach → Small Intestine (duodenum, jejunum, ileum) → Large Intestine (cecum, colon, rectum) → Anus.

Pathway of Urine Formation

The journey travels from Renal Artery → Afferent Arteriole → Glomerulus (filtration) → Bowman's Capsule → Proximal Convoluted Tubule → Loop of Henle → Distal Convoluted Tubule → Collecting Duct → Renal Pelvis → Ureter → Bladder → Urethra.

Pathway of Sperm

The route sperm travels: Seminiferous Tubules → Rete Testis → Efferent Ductules → Epididymis → Vas Deferens → Ejaculatory Duct → Urethra → Female Reproductive System.

Small Intestine

Comprises Duodenum → Jejunum → Ileum.

Large Intestine

Includes Cecum → Ascending Colon → Transverse Colon → Descending Colon → Sigmoid Colon → Rectum → Anal Canal.