Anatomy of the Ear

from reportlab.lib.pagesizes import A4
from reportlab.lib.units import cm
from reportlab.lib.styles import getSampleStyleSheet, ParagraphStyle
from reportlab.lib.enums import TA_CENTER
from reportlab.platypus import (
    SimpleDocTemplate, Paragraph, Spacer, Image, Table, TableStyle,
    PageBreak, ListFlowable, ListItem, KeepTogether
)
from reportlab.lib import colors
from PIL import Image as PILImage
import os

ASSETS = "/tmp/workspace/ear-anatomy/assets"
OUT = "/tmp/workspace/ear-anatomy/output/Anatomy_of_the_Ear.pdf"

styles = getSampleStyleSheet()

title_style = ParagraphStyle(
    "TitleStyle", parent=styles["Title"], fontSize=22, spaceAfter=6, textColor=colors.HexColor("#1a3c6e")
)
subtitle_style = ParagraphStyle(
    "Subtitle", parent=styles["Normal"], fontSize=11, alignment=TA_CENTER, textColor=colors.grey, spaceAfter=18
)
h1 = ParagraphStyle(
    "H1", parent=styles["Heading1"], fontSize=16, textColor=colors.HexColor("#1a3c6e"),
    spaceBefore=14, spaceAfter=8, borderPadding=0
)
h2 = ParagraphStyle(
    "H2", parent=styles["Heading2"], fontSize=13, textColor=colors.HexColor("#2f5d8a"),
    spaceBefore=10, spaceAfter=6
)
body = ParagraphStyle(
    "Body", parent=styles["Normal"], fontSize=10.5, leading=15, spaceAfter=8, alignment=4
)
bullet_style = ParagraphStyle(
    "Bullet", parent=body, leftIndent=14, spaceAfter=4
)
caption_style = ParagraphStyle(
    "Caption", parent=styles["Normal"], fontSize=9, alignment=TA_CENTER, textColor=colors.grey,
    spaceAfter=14, spaceBefore=4, fontName="Helvetica-Oblique"
)
source_style = ParagraphStyle(
    "Source", parent=styles["Normal"], fontSize=8.5, textColor=colors.grey, spaceBefore=20
)

def img_flowable(path, max_width=13*cm, max_height=8*cm):
    with PILImage.open(path) as im:
        w, h = im.size
    ratio = w / h
    width = max_width
    height = width / ratio
    if height > max_height:
        height = max_height
        width = height * ratio
    return Image(path, width=width, height=height)

story = []

# Title page header
story.append(Paragraph("Anatomy of the Ear", title_style))
story.append(Paragraph("External, Middle, and Internal Ear Structures & Function", subtitle_style))

# Intro
story.append(Paragraph(
    "The ear is divided into three anatomical regions: the <b>external (outer) ear</b>, the "
    "<b>middle ear</b>, and the <b>internal (inner) ear</b>. The first two are concerned mainly "
    "with conducting sound, while the internal ear houses the organs of hearing and balance.",
    body
))

# Composite image
story.append(img_flowable(os.path.join(ASSETS, "composite_cross_section.jpg"), max_width=14*cm, max_height=8*cm))
story.append(Paragraph("Labeled cross-section of outer, middle, and inner ear structures", caption_style))

# 1. External Ear
story.append(Paragraph("1. External Ear", h1))
story.append(Paragraph("Consists of two parts:", body))
ext_items = [
    "<b>Auricle (pinna)</b> - the visible projection on the side of the head, made of elastic cartilage covered by skin, shaped to capture sound. Landmarks include the <b>helix</b> (outer rim), <b>antihelix</b>, <b>tragus</b> and <b>antitragus</b>, <b>concha</b> (hollow center), and the <b>lobule</b> (the only part without cartilage support).",
    "<b>External acoustic meatus</b> - the canal leading from the concha inward to the tympanic membrane, directing sound waves toward the middle ear.",
]
story.append(ListFlowable([ListItem(Paragraph(t, bullet_style)) for t in ext_items], bulletType="bullet"))
story.append(Paragraph(
    "Both intrinsic and extrinsic auricular muscles are present but are largely vestigial in humans; "
    "they are innervated by the <b>facial nerve (CN VII)</b>. Sensory supply to the auricle comes from "
    "multiple sources: the great auricular and lesser occipital nerves (cervical plexus), the auriculotemporal "
    "nerve (CN V3), and branches of CN VII and CN X.",
    body
))

story.append(img_flowable(os.path.join(ASSETS, "auricle.png"), max_width=9*cm, max_height=7*cm))
story.append(Paragraph("Fig. Auricle - surface landmarks", caption_style))

story.append(img_flowable(os.path.join(ASSETS, "innervation.png"), max_width=9*cm, max_height=7*cm))
story.append(Paragraph("Fig. Sensory innervation of the auricle", caption_style))

# 2. Middle Ear
story.append(Paragraph("2. Middle Ear (Tympanic Cavity)", h1))
story.append(Paragraph(
    "An air-filled space in the petrous temporal bone, situated between the tympanic membrane laterally "
    "and the internal ear medially. Key components:", body
))
mid_items = [
    "<b>Tympanic membrane</b> - thin, translucent partition that vibrates in response to sound.",
    "<b>Auditory ossicles</b> - the <b>malleus</b>, <b>incus</b>, and <b>stapes</b>, forming a lever chain that transmits and amplifies vibrations from the tympanic membrane to the oval window of the internal ear. The stapes footplate sits in the oval window.",
    "<b>Associated muscles</b> - <b>tensor tympani</b> (innervated by CN V3) and <b>stapedius</b> (innervated by CN VII), which dampen excessive ossicular movement (acoustic reflex).",
    "<b>Pharyngotympanic (Eustachian) tube</b> - connects the middle ear to the nasopharynx, equalizing air pressure across the tympanic membrane.",
    "<b>Mastoid antrum and air cells</b> - posterior air-filled extension of the middle ear cavity.",
]
story.append(ListFlowable([ListItem(Paragraph(t, bullet_style)) for t in mid_items], bulletType="bullet"))
story.append(Paragraph(
    "The <b>chorda tympani</b> (a branch of CN VII carrying taste fibers) and the tympanic plexus (CN IX) "
    "pass through this cavity.", body
))

# 3. Internal Ear
story.append(Paragraph("3. Internal (Inner) Ear", h1))
story.append(Paragraph(
    "Located in the petrous part of the temporal bone, medial to the middle ear. It consists of the "
    "<b>bony labyrinth</b> (bony cavities filled with perilymph) containing a <b>membranous labyrinth</b> "
    "(filled with endolymph):", body
))
inner_items = [
    "<b>Bony labyrinth</b>: vestibule, three semicircular canals, and cochlea.",
    "<b>Membranous labyrinth</b>: semicircular ducts, cochlear duct, and two sacs - the <b>utricle</b> and <b>saccule</b>.",
]
story.append(ListFlowable([ListItem(Paragraph(t, bullet_style)) for t in inner_items], bulletType="bullet"))

story.append(Paragraph(
    "<b>Vestibule</b> - the central chamber, contains the oval window and connects anteriorly to the cochlea, "
    "posterosuperiorly to the semicircular canals.", body
))
story.append(Paragraph(
    "<b>Semicircular canals</b> (anterior, posterior, lateral) - each forms two-thirds of a circle, oriented "
    "at right angles to one another, with a dilated <b>ampulla</b> at one end; they detect rotational "
    "(angular) head movements.", body
))
story.append(Paragraph(
    "<b>Cochlea</b> - a coiled bony tube (about 2.5 turns) housing the <b>cochlear duct</b> and the "
    "<b>organ of Corti</b>, the sensory organ of hearing, which converts fluid vibrations into neural signals.",
    body
))
story.append(Paragraph(
    "<b>Utricle and saccule</b> - contain maculae that detect linear acceleration and head position (gravity).",
    body
))
story.append(Paragraph(
    "The <b>vestibulocochlear nerve (CN VIII)</b> enters via the internal acoustic meatus and splits into:",
    body
))
cn8_items = [
    "<b>Vestibular part</b> - balance information from semicircular ducts, utricle, saccule",
    "<b>Cochlear part</b> - hearing information from the cochlear duct",
]
story.append(ListFlowable([ListItem(Paragraph(t, bullet_style)) for t in cn8_items], bulletType="bullet"))

story.append(img_flowable(os.path.join(ASSETS, "internal_ear_location.png"), max_width=9.5*cm, max_height=7.5*cm))
story.append(Paragraph("Fig. Location of the internal ear in the temporal bone", caption_style))

story.append(PageBreak())

story.append(img_flowable(os.path.join(ASSETS, "internal_ear_relationships.png"), max_width=12*cm, max_height=15*cm))
story.append(Paragraph("Fig. Anatomical relationships of internal ear structures", caption_style))

# Functional summary table
story.append(Paragraph("Functional Summary", h1))
table_data = [
    ["Region", "Main Structures", "Function"],
    ["External ear", "Auricle, external acoustic meatus", "Sound collection and conduction"],
    ["Middle ear", "Tympanic membrane, ossicles, Eustachian tube", "Sound transmission/amplification, pressure equalization"],
    ["Internal ear", "Cochlea, vestibule, semicircular canals", "Hearing (cochlea) and balance (vestibular apparatus)"],
]
tbl = Table(table_data, colWidths=[3.2*cm, 6.3*cm, 6.5*cm])
tbl.setStyle(TableStyle([
    ("BACKGROUND", (0, 0), (-1, 0), colors.HexColor("#1a3c6e")),
    ("TEXTCOLOR", (0, 0), (-1, 0), colors.white),
    ("FONTNAME", (0, 0), (-1, 0), "Helvetica-Bold"),
    ("FONTSIZE", (0, 0), (-1, -1), 9),
    ("GRID", (0, 0), (-1, -1), 0.5, colors.grey),
    ("VALIGN", (0, 0), (-1, -1), "TOP"),
    ("ROWBACKGROUNDS", (0, 1), (-1, -1), [colors.whitesmoke, colors.white]),
    ("LEFTPADDING", (0, 0), (-1, -1), 6),
    ("RIGHTPADDING", (0, 0), (-1, -1), 6),
    ("TOPPADDING", (0, 0), (-1, -1), 5),
    ("BOTTOMPADDING", (0, 0), (-1, -1), 5),
]))
story.append(tbl)

story.append(Paragraph(
    "Source: Gray's Anatomy for Students (pp. 1093-1106); Cummings Otolaryngology Head and Neck Surgery.",
    source_style
))

doc = SimpleDocTemplate(
    OUT, pagesize=A4,
    leftMargin=2*cm, rightMargin=2*cm, topMargin=2*cm, bottomMargin=2*cm,
    title="Anatomy of the Ear"
)
doc.build(story)
print("PDF written to", OUT)