Study sheet: Human Biosciences Foundations

📋 Course Outline

1. Human Bioscience Disciplines
2. Homeostatic Control
3. Levels and Tissues
4. Cardiovascular Structures
5. Circulation and Cardiac Function
6. Blood and Haemostasis
7. Respiratory Structures and Exchange
8. Respiratory Regulation and Disorders

📖 1. Human Bioscience Disciplines

🔑 Key Concepts & Definitions

• Anatomy : the study of the structures of the human body
• Physiology : the study of the functions and activities of living organisms and their parts, including physical and chemical processes
• Pathology : the study of diseases, their causes, processes, development and consequences
• Pharmacology : the science of drugs and their effects on the human body

📖 2. Homeostatic Control

🔑 Key Concepts & Definitions

• Homeostasis : the process of maintaining a stable internal environment
• Control centre : determines the set point, analyses information and determines the appropriate response
• Effector : an organ that produces an effect after stimulation by the nervous system or a hormone, including muscles and endocrine glands that correct an imbalance

★ Must-know

• Homeostatic control maintains:

  • body temperature
  • fluid and electrolyte balance
  • blood pH
  • blood pressure
  • blood glucose

• 🔄 Homeostatic control proceeds through:

  1. receptors
  2. the control centre
  3. effectors

Further detail

• The receptor types respond to:
  • temperature changes
  • osmolarity changes
  • chemical changes

💡 Memory Hook

Receptor → control centre → effector

📖 3. Levels and Tissues

🔑 Key Concepts & Definitions

• Tissue : a collection of similar cells that act together to perform a function
• Connective tissue : joins tissues together, is the most common tissue in the body and ranges from fluid to solid

★ Must-know

• 🔄 The levels of organisation progress through:

  1. chemical
  2. cellular
  3. tissue
  4. organ
  5. system
  6. organism

• The four tissue types are:

  • epithelial tissue
  • connective tissue
  • muscle tissue
  • nervous tissue

• The three muscle tissue types are:

  • skeletal muscle attached to the skeleton
  • cardiac muscle in the heart
  • smooth muscle in internal organs and blood vessels

Further detail

• Nervous tissue rapidly transmits messages through neurons, while glia provide metabolic support for neurons.

💡 Memory Hook

Chemical → cellular → tissue → organ → system → organism

📖 4. Cardiovascular Structures

🔑 Key Concepts & Definitions

• Circulatory system : transports fluids around the body and consists of the heart, blood vessels, blood, lymphatic vessels and lymph fluid
• Heart : a muscular pump in the thoracic cavity’s mediastinum that creates pressure to force blood around the body

★ Must-know

• The four heart chambers are:

  • right atrium
  • left atrium
  • right ventricle
  • left ventricle

• Arteries carry blood away from the heart, veins return blood to the heart, and capillaries connect arteries and veins and allow material exchange through thin walls.

Further detail

• An average adult has approximately 5 to 5.5 L of blood, which consists of cells and plasma, with plasma being 90% water.

💡 Memory Hook

The heart as a muscular pump connected to vessel pipes

📖 5. Circulation and Cardiac Function

★ Must-know

📌 Systole is ventricular contraction that forces blood out of the heart, whereas diastole is ventricular relaxation during which the heart fills with blood.

• 🔄 The conduction pathway includes:
  1. sinoatrial node
  2. atrioventricular node
  3. atrioventricular bundle
  4. Purkinje fibres

📌 The pulmonary circuit carries blood between the heart and lungs, whereas the systemic circuit carries blood to and from the rest of the body.

• Normal blood pressure is approximately 120–129 mmHg during the heartbeat and 80–84 mmHg between beats.

Further detail

• Lymph moves toward the heart through one-way lymphatic valves, aided by nearby arterial pulsation and muscle squeezing, before draining into the bloodstream through ducts in the upper chest.

💡 Memory Hook

Systole ejects blood, whereas diastole fills the heart

📖 6. Blood and Haemostasis

★ Must-know

• The formed elements include:

  • red blood cells
  • white blood cells
  • platelets

• Red blood cells lack a nucleus, cannot divide, and are produced in red bone marrow by erythropoiesis.

• Haemostasis is a positive homeostatic feedback process in which vessel damage exposes collagen, platelets attach and recruit more platelets, a plug forms, and serotonin constricts the vessel.

📌 Blood type A has A antigens and anti-B antibodies, type B has B antigens and anti-A antibodies, type AB has both antigens and no antibodies, and type O has neither antigen but both antibodies.

Further detail

• Plasma makes up approximately 55% of blood volume and contains water plus dissolved nutrients, gases, hormones, salts and plasma proteins.

📖 7. Respiratory Structures and Exchange

🔑 Key Concepts & Definitions

• Respiratory system : brings oxygen into the body and removes carbon dioxide from it; oxygen and glucose are used to make ATP through cellular respiration
• Alveoli : terminal air sacs surrounded by capillaries where oxygen diffuses into blood and carbon dioxide diffuses into the alveoli across the respiratory membrane

📝 Essential Points

• The right lung has three lobes and the left lung has two lobes because the cardiac notch provides space for the heart.

• The upper and lower tracts contain:

  • nose and nasal cavity
  • oral cavity
  • pharynx
  • larynx
  • trachea
  • bronchi
  • bronchioles
  • alveoli

📌 Ventilation is the movement of air into and out of the lungs, whereas respiration is gas exchange across the respiratory membrane.

💡 Memory Hook

Trachea → bronchi → bronchioles → alveoli

📖 8. Respiratory Regulation and Disorders

★ Must-know

• Inhaled air contains approximately 20% oxygen and almost no carbon dioxide, whereas exhaled air contains approximately 16% oxygen and 5% carbon dioxide.

• Oxygen binds to haemoglobin, whose four subunits each contain an iron atom capable of binding one oxygen molecule, and binding becomes easier for the remaining molecules through cooperative binding.

• Carbon dioxide is transported:

  • as bicarbonate ions
  • bound to haemoglobin as carbaminohaemoglobin
  • dissolved in plasma

• When oxygen levels fall or carbon dioxide levels rise, chemoreceptor activity increases and breathing becomes deeper and faster; excessive ventilation lowers carbon dioxide and decreases breathing.

Further detail

• High-altitude acclimatisation involves:

  • deeper breathing
  • increased haemoglobin production
  • increased red blood cell production
  • more blood vessels in tissues

• Respiratory disorders include allergic rhinitis, asthma, chronic obstructive pulmonary disease, cystic fibrosis, respiratory infections, interstitial lung disease, blockages, acid-base imbalances, hypoxemia, hypoxia, hypercapnia, lung cancer, suffocation, drowning and aspiration.

💡 Memory Hook

Low oxygen or high carbon dioxide → deeper and faster breathing

📊 Synthesis Tables

Blood Vessel Comparison

Vessel	Direction	Main function
Arteries	Away from heart	Carry blood under pressure
Veins	Toward heart	Return blood passively
Capillaries	Between arteries and veins	Exchange gases, nutrients and waste

Respiratory Process Comparison

Process	Description	Main site
Ventilation	Movement of air into and out of lungs	Respiratory tract
External respiration	Gas exchange between alveoli and blood	Respiratory membrane
Gas transport	Movement of oxygen and carbon dioxide in blood	Bloodstream