Anatomy and Physiology of the Cardiovascular and Respiratory Systems: Asthma Case Study

from docx import Document
from docx.shared import Inches, Pt, RGBColor
from docx.enum.text import WD_ALIGN_PARAGRAPH
from docx.enum.table import WD_TABLE_ALIGNMENT, WD_CELL_VERTICAL_ALIGNMENT
from docx.oxml import OxmlElement
from docx.oxml.ns import qn
from docx.enum.section import WD_SECTION
from docx.enum.style import WD_STYLE_TYPE
from docx.enum.text import WD_BREAK
import matplotlib.pyplot as plt
from matplotlib.patches import FancyBboxPatch, FancyArrowPatch
import os, re

BASE = '/tmp/workspace/cardiopulmonary-report'
OUT = os.path.join(BASE, 'output', 'Cardiovascular_and_Respiratory_Systems_Report.docx')
ASSETS = os.path.join(BASE, 'assets')
os.makedirs(ASSETS, exist_ok=True)

# ---------- diagrams ----------
def box(ax, x, y, text, w=1.7, h=.55, color='#eaf2f8'):
    p = FancyBboxPatch((x-w/2,y-h/2),w,h,boxstyle='round,pad=0.04',facecolor=color,edgecolor='#1f4e79',linewidth=1.1)
    ax.add_patch(p); ax.text(x,y,text,ha='center',va='center',fontsize=8,wrap=True)
def arrow(ax, x1,y1,x2,y2):
    ax.add_patch(FancyArrowPatch((x1,y1),(x2,y2),arrowstyle='-|>',mutation_scale=12,color='#1f4e79',linewidth=1.2))
fig, ax = plt.subplots(figsize=(9,5)); ax.set_xlim(0,10); ax.set_ylim(0,5); ax.axis('off')
box(ax,1,2.5,'Body tissues\n(deoxygenated blood)',2.0,.72,'#fdecea'); box(ax,3.1,2.5,'Venae cavae',1.45,.55)
box(ax,5.0,3.5,'Right atrium',1.45,.55); box(ax,6.9,3.5,'Right ventricle',1.55,.55); box(ax,8.9,3.5,'Lungs\nO₂ in, CO₂ out',1.55,.7,'#e8f6f3')
box(ax,8.9,1.35,'Pulmonary veins',1.65,.55); box(ax,6.8,1.35,'Left atrium',1.45,.55); box(ax,4.85,1.35,'Left ventricle',1.55,.55); box(ax,2.8,1.35,'Aorta',1.25,.55)
for a in [(2.05,2.5,2.38,2.5),(3.83,2.5,4.65,3.3),(5.75,3.5,6.1,3.5),(7.7,3.5,8.1,3.5),(8.9,3.13,8.9,1.75),(8.05,1.35,7.55,1.35),(6.05,1.35,5.65,1.35),(4.05,1.35,3.45,1.35),(2.18,1.35,1.0,2.1)]: arrow(ax,*a)
ax.text(5,4.6,'Blood flow through the heart and pulmonary circulation',ha='center',fontsize=13,fontweight='bold',color='#17365d')
fig.tight_layout(); heart_img=os.path.join(ASSETS,'heart_circulation.png'); fig.savefig(heart_img,dpi=200,bbox_inches='tight'); plt.close(fig)

fig, ax = plt.subplots(figsize=(7.5,7)); ax.set_xlim(0,10); ax.set_ylim(0,12); ax.axis('off')
for y,label,w in [(11,'Nose / nasal cavity',2.3),(9.9,'Pharynx',1.6),(8.8,'Larynx',1.5),(7.7,'Trachea',1.5)]: box(ax,5,y,label,w,.52)
box(ax,2.8,6.3,'Right primary\nbronchus',1.8,.65); box(ax,7.2,6.3,'Left primary\nbronchus',1.8,.65)
box(ax,2.3,4.7,'Bronchioles',1.7,.52); box(ax,7.7,4.7,'Bronchioles',1.7,.52)
box(ax,2.2,3.1,'Alveolar sacs\n(alveoli)',1.8,.65,'#e8f6f3'); box(ax,7.8,3.1,'Alveolar sacs\n(alveoli)',1.8,.65,'#e8f6f3')
box(ax,5,1.25,'Diaphragm',2.0,.55,'#fcf3cf')
for a in [(5,10.72,5,10.18),(5,9.62,5,9.08),(5,8.52,5,7.98),(4.45,7.45,3.2,6.65),(5.55,7.45,6.8,6.65),(2.65,5.95,2.4,5.0),(7.35,5.95,7.6,5.0),(2.3,4.43,2.2,3.45),(7.7,4.43,7.8,3.45)]: arrow(ax,*a)
ax.text(5,11.7,'Major structures of the respiratory system',ha='center',fontsize=13,fontweight='bold',color='#17365d')
fig.tight_layout(); resp_img=os.path.join(ASSETS,'respiratory_system.png'); fig.savefig(resp_img,dpi=200,bbox_inches='tight'); plt.close(fig)

# ---------- document helpers ----------
doc=Document()
sec=doc.sections[0]; sec.top_margin=Inches(.75); sec.bottom_margin=Inches(.75); sec.left_margin=Inches(.8); sec.right_margin=Inches(.8)
styles=doc.styles
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for name,size,color in [('Title',18,'17365D'),('Heading 1',14,'17365D'),('Heading 2',12,'1F4E79')]:
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caption=styles.add_style('Figure Caption',WD_STYLE_TYPE.PARAGRAPH); caption.font.name='Arial'; caption.font.size=Pt(9); caption.font.italic=True; caption.paragraph_format.alignment=WD_ALIGN_PARAGRAPH.CENTER; caption.paragraph_format.space_after=Pt(5); caption.paragraph_format.line_spacing=1

def set_cell_shading(cell, fill):
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def add_para(text, italic=False):
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    r=p.add_run(text); r.italic=italic
    return p

def add_heading(text, level=1): doc.add_heading(text, level=level)

# cover
p=doc.add_paragraph(); p.alignment=WD_ALIGN_PARAGRAPH.CENTER; p.paragraph_format.space_before=Pt(80)
r=p.add_run('Anatomy and Physiology of the\nCardiovascular and Respiratory Systems'); r.bold=True; r.font.size=Pt(20); r.font.color.rgb=RGBColor(23,54,93)
p=doc.add_paragraph(); p.alignment=WD_ALIGN_PARAGRAPH.CENTER; p.add_run('Including a Case Study of Asthma').italic=True
for label in ['Student name: ______________________________','Student ID: __________________________________','Module: ______________________________________','Submission date: ______________________________']:
    p=doc.add_paragraph(); p.alignment=WD_ALIGN_PARAGRAPH.CENTER; p.paragraph_format.space_before=Pt(9); p.add_run(label)
doc.add_page_break()

p=doc.add_paragraph(); p.alignment=WD_ALIGN_PARAGRAPH.CENTER; r=p.add_run('Anatomy and Physiology of the Cardiovascular and Respiratory Systems: Asthma Case Study'); r.bold=True; r.font.size=Pt(16); r.font.color.rgb=RGBColor(23,54,93)
p=doc.add_paragraph(); p.alignment=WD_ALIGN_PARAGRAPH.CENTER; p.add_run('Approximate word count: 1,900 words (excluding references and captions)').italic=True

add_heading('1. Introduction')
add_para('This report explains the anatomy and physiology of the cardiovascular and respiratory systems and evaluates how they work together to maintain oxygen delivery and carbon dioxide removal. It examines the structure and pumping action of the mammalian heart, the cardiac cycle and its electrical control, blood vessels and red blood cells. The report also discusses respiratory anatomy, ventilation, alveolar gas exchange and the response to exercise. Finally, it presents a case study of asthma to demonstrate how disease can disrupt normal cardiopulmonary function.')

add_heading('2. Heart structure and function')
add_para('The heart is a muscular organ located in the mediastinum, between the lungs and slightly to the left of the midline. It acts as a double pump: the right side pumps deoxygenated blood to the lungs through the pulmonary circulation, whereas the left side pumps oxygenated blood to the body through the systemic circulation.')
add_para('The heart has four chambers. The right atrium receives deoxygenated blood from the superior and inferior vena cava. Blood then passes through the tricuspid valve into the right ventricle. When the right ventricle contracts, blood is ejected through the pulmonary valve into the pulmonary artery and travels to the lungs. In the lungs, carbon dioxide is removed and oxygen is absorbed.')
add_para('Oxygenated blood returns from the lungs in the pulmonary veins and enters the left atrium. It flows through the mitral, also called bicuspid, valve into the left ventricle. The left ventricle has the thickest myocardium because it must generate sufficient pressure to pump blood around the entire body. During ventricular contraction, blood passes through the aortic valve into the aorta and systemic circulation (Tortora and Derrickson, 2021).')
add_para('The septum separates the right and left sides of the heart, preventing mixing of oxygenated and deoxygenated blood. Heart valves maintain one-way flow. The atrioventricular valves, tricuspid and mitral, prevent blood returning to the atria during ventricular systole. The semilunar valves, pulmonary and aortic, prevent blood flowing back into the ventricles after ejection.')
p=doc.add_paragraph(); p.alignment=WD_ALIGN_PARAGRAPH.CENTER; p.add_run().add_picture(heart_img,width=Inches(6.55)); doc.add_paragraph('Figure 1. Simplified route of blood through the heart and lungs.',style='Figure Caption')
add_para('The myocardium requires a continuous oxygen supply. The right and left coronary arteries arise from the aorta and supply the heart muscle. If a coronary artery becomes narrowed or blocked, myocardial oxygen supply can become inadequate, leading to angina or myocardial infarction.')

add_heading('The cardiac cycle and electrical activity',2)
add_para('The cardiac cycle consists of coordinated relaxation, termed diastole, and contraction, termed systole. During ventricular diastole, the ventricles relax and fill with blood. Most filling occurs passively, but atrial systole provides an additional volume at the end of ventricular filling, often called the atrial kick. Ventricular systole begins when ventricular pressure rises above atrial pressure. The atrioventricular valves close, producing the first heart sound, “lub”. When ventricular pressure exceeds pressure in the pulmonary artery and aorta, the semilunar valves open and blood is ejected. As the ventricles relax, their pressure falls below that in the great arteries; the aortic and pulmonary valves close, producing the second heart sound, “dub”.')
add_para('The heartbeat is myogenic, meaning cardiac muscle generates its own electrical impulses. The sinoatrial node in the right atrium is the natural pacemaker. Its depolarisation spreads across both atria, causing atrial contraction. The impulse reaches the atrioventricular node, where a brief delay permits ventricular filling before ventricular contraction. The signal then travels through the bundle of His, right and left bundle branches, and Purkinje fibres. This produces coordinated contraction from the ventricular apex upwards, enabling efficient ejection into the pulmonary artery and aorta. The autonomic nervous system modifies this intrinsic rhythm: sympathetic stimulation increases heart rate and contractility, while parasympathetic vagal stimulation lowers heart rate (Hall, 2021).')

add_heading('3. Blood vessels and red blood cells')
add_para('Blood vessels form a continuous network that supports the pumping action of the heart. Arteries carry blood away from the heart, veins return blood to the heart, and capillaries are microscopic exchange vessels linking the two.')
table=doc.add_table(rows=1, cols=4); table.alignment=WD_TABLE_ALIGNMENT.CENTER; table.style='Table Grid'
hdr=table.rows[0].cells
for c,t in zip(hdr,['Feature','Arteries','Capillaries','Veins']): c.text=t; set_cell_shading(c,'D9EAF7'); c.vertical_alignment=WD_CELL_VERTICAL_ALIGNMENT.CENTER
rows=[('Direction','Away from heart','Between arterioles and venules','Towards heart'),('Wall','Thick, muscular and elastic','One endothelial cell thick','Thinner, less muscle and elastin'),('Lumen','Relatively narrow','Extremely narrow','Wide'),('Pressure','High','Falls across capillary bed','Low'),('Valves','Absent, except at heart exits','Absent','Present, especially in limbs'),('Main function','Distribute blood under pressure','Exchange gases, nutrients and wastes','Return blood and act as reservoir')]
for row in rows:
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for row in table.rows:
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add_para('All vessels are lined by endothelium, providing a smooth surface for blood flow, but their structures reflect different functions. Arterial walls contain smooth muscle and elastic tissue. Elastic recoil helps maintain pressure between heartbeats, and smooth muscle changes vessel diameter to control tissue perfusion. Capillaries have a single-cell wall, giving a short diffusion distance for oxygen, carbon dioxide, nutrients and metabolic wastes. Their narrow diameter slows flow and brings red blood cells near the wall. Veins have wider lumens and operate under low pressure; skeletal-muscle contractions and valves assist venous return, particularly from the lower limbs.')
add_para('Red blood cells, also called erythrocytes, transport oxygen from the lungs to tissues and assist carbon dioxide transport back to the lungs. Their main component is haemoglobin, an iron-containing protein that binds oxygen reversibly. In the lungs, where oxygen partial pressure is high, haemoglobin loads oxygen. In metabolically active tissues, where oxygen partial pressure is lower and carbon dioxide is higher, it releases oxygen.')
add_para('Their biconcave disc shape provides a large surface-area-to-volume ratio for rapid diffusion. The thin centre shortens diffusion distance. Mature red blood cells lack a nucleus and most organelles, leaving more space for haemoglobin. They also lack mitochondria and therefore do not consume the oxygen they transport. Flexibility allows passage through capillaries narrower than their resting diameter (OpenStax, 2023).')

add_heading('4. Structure and function of the respiratory system')
add_para('The respiratory system conducts air to the gas-exchange surfaces of the lungs and removes carbon dioxide. Air usually enters through the nose or mouth. The nasal cavity warms, filters and humidifies inspired air. Air then passes through the pharynx, larynx and trachea. The trachea is supported by C-shaped cartilage rings that prevent airway collapse.')
add_para('The trachea divides into right and left primary bronchi, which enter the lungs. Repeated branching forms smaller bronchi, bronchioles, terminal bronchioles and respiratory bronchioles. These end in alveolar ducts and alveoli. The lungs are covered by pleural membranes. Pleural fluid between the visceral and parietal pleura reduces friction as the lungs move during breathing.')
p=doc.add_paragraph(); p.alignment=WD_ALIGN_PARAGRAPH.CENTER; p.add_run().add_picture(resp_img,width=Inches(5.6)); doc.add_paragraph('Figure 2. Labelled diagram of the respiratory system.',style='Figure Caption')
add_para('Inhalation is active. The diaphragm contracts and flattens while the external intercostal muscles lift the ribs upwards and outwards. Thoracic volume increases, reducing intrathoracic pressure below atmospheric pressure. Air moves into the lungs down this pressure gradient. During quiet exhalation, the inspiratory muscles relax. Elastic recoil of the lungs and chest wall reduces thoracic volume, increasing intrapulmonary pressure and moving air out. During exercise or forced expiration, the internal intercostal and abdominal muscles actively decrease thoracic volume further.')

add_heading('Alveolar gas exchange and diffusion',2)
add_para('Alveoli are microscopic air sacs surrounded by dense capillary networks. They provide a large surface area for gas exchange. Each alveolus has a very thin wall, principally made of type I alveolar epithelial cells. Capillary walls are also only one cell thick, creating a short alveolar-capillary diffusion distance. Type II alveolar cells make surfactant, which lowers surface tension and helps prevent alveolar collapse.')
add_para('Gas exchange occurs by simple diffusion: molecules move from an area of higher partial pressure to one of lower partial pressure. Oxygen partial pressure is higher in alveolar air than in deoxygenated pulmonary capillary blood, so oxygen diffuses into blood and binds to haemoglobin. Carbon dioxide partial pressure is higher in pulmonary capillary blood than in alveolar air, so it diffuses into alveoli and is exhaled. Fick’s law states that diffusion increases with surface area and the partial-pressure gradient, but decreases as membrane thickness rises. The lungs are adapted to this law through millions of thin-walled alveoli and continuing ventilation and perfusion, which maintain steep gradients (Hall, 2021).')

add_heading('5. Exercise, ventilation and homeostasis')
add_para('At rest, ventilation maintains relatively stable arterial oxygen, carbon dioxide and pH. During exercise, working muscles require more ATP, consume more oxygen and produce more carbon dioxide. Ventilation rises through increases in tidal volume, the volume of each breath, and respiratory rate. Minute ventilation equals respiratory rate multiplied by tidal volume.')
add_para('Initially, neural signals from the motor cortex and sensory input from working muscles stimulate respiratory centres in the medulla. As exercise continues, increased carbon dioxide and hydrogen ion concentrations are detected by chemoreceptors. Central chemoreceptors respond mainly to carbon dioxide-related changes in cerebrospinal-fluid pH; peripheral chemoreceptors in the carotid and aortic bodies respond to changes in oxygen, carbon dioxide and pH. Increased ventilation removes excess carbon dioxide and helps limit acidosis. At the same time, cardiac output increases through increased heart rate and stroke volume. More oxygenated blood reaches active skeletal muscles and more carbon dioxide returns to the lungs. These coordinated adjustments illustrate homeostasis because stable internal conditions are maintained despite greater metabolic demand.')

add_heading('6. Case study: Asthma')
add_para('Asthma is a chronic inflammatory airway disease characterised by variable respiratory symptoms and variable expiratory airflow limitation. Symptoms include wheeze, breathlessness, chest tightness and cough. Common triggers include allergens, viral infection, cold air, smoke, pollution and exercise.')
add_para('A hypothetical case concerns Amelia, a 21-year-old university student with childhood eczema and seasonal allergic rhinitis. She reports intermittent wheeze, nocturnal cough and breathlessness when running. Symptoms worsened after a viral upper-respiratory infection. Spirometry shows reduced expiratory airflow with significant improvement following a bronchodilator, supporting an asthma diagnosis.')
add_para('In asthma, airway inflammation causes bronchial smooth-muscle constriction, mucosal swelling and increased mucus production. These changes narrow bronchi and bronchioles. Resistance rises sharply as airway radius falls. Expiration is particularly difficult because small airways narrow further as intrathoracic pressure increases, producing air trapping, hyperinflation and breathlessness.')
add_para('Asthma can disrupt ventilation and gas exchange. Some alveoli may receive inadequate ventilation despite maintained blood flow, causing ventilation-perfusion mismatch. Mild or moderate attacks often cause low carbon dioxide because the person hyperventilates. In severe asthma, fatigue and increasing obstruction can cause carbon dioxide retention, a serious sign requiring urgent assessment. Thus, asthma impairs the respiratory part of cardiopulmonary function and, during a severe attack, may increase the workload of the cardiovascular system.')
add_para('Amelia’s management should include education on trigger avoidance, correct inhaler technique and a personalised asthma action plan. Reliever bronchodilators relax airway smooth muscle and provide rapid symptom relief. Inhaled corticosteroids reduce airway inflammation and lower exacerbation risk. Treatment should be reviewed regularly because control and adherence can change. NHS guidance identifies inhaled medicines as the main treatment and stresses correct technique and routine review (NHS, 2025). An umbrella review indicates that appropriately managed exercise may improve fitness and quality of life in people with asthma, although exercise-induced symptoms require good underlying control and an individual plan (Huang, Yang and Ma, 2025).')

add_heading('7. Conclusion')
add_para('The cardiovascular and respiratory systems are interdependent. The heart generates pressure to circulate blood through pulmonary and systemic circuits, while arteries, capillaries and veins enable distribution, exchange and venous return. Red blood cells are specialised for oxygen transport. The respiratory system conducts air to alveoli, where diffusion across a thin alveolar-capillary membrane exchanges oxygen and carbon dioxide. During exercise, ventilation and cardiac output rise to preserve oxygen delivery, carbon dioxide removal and acid-base balance. Asthma demonstrates how airway inflammation, bronchoconstriction and mucus production impair ventilation and disrupt normal gas exchange.')

add_heading('Reference List')
refs=['Hall, J.E. (2021) Guyton and Hall textbook of medical physiology. 14th edn. Philadelphia: Elsevier.','Huang, F., Yang, S. and Ma, M. (2025) ‘Effects of physical exercises in asthma: an umbrella review of systematic reviews and meta-analysis’, Clinical Respiratory Journal, 19, e70075. doi: 10.1111/crj.70075.','NHS (2025) Asthma. Available at: https://www.nhs.uk/conditions/asthma/ (Accessed: 23 October 2026).','OpenStax (2023) Anatomy and Physiology 2e. Houston, TX: OpenStax, Rice University. Available at: https://openstax.org/details/books/anatomy-and-physiology-2e (Accessed: 23 October 2026).','Tortora, G.J. and Derrickson, B. (2021) Principles of anatomy and physiology. 16th edn. Hoboken, NJ: Wiley.']
for ref in refs:
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# footer page field
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doc.save(OUT)
print(OUT)