FSC Part 2 Biology Notes

Chapter 1: Circulation

Blood Composition

• Plasma (55%): Water, proteins, nutrients, hormones
• Red Blood Cells: Transport oxygen (hemoglobin)
• White Blood Cells: Immunity
• Platelets: Blood clotting

Blood Groups

• AB: Universal recipient
• O: Universal donor

Heart Structure

• Right atrium → Right ventricle → Pulmonary artery
• Left atrium → Left ventricle → Aorta

Cardiac Cycle

1. Systole: Contraction
2. Diastole: Relaxation

Blood Vessels

• Arteries: Carry away from heart, thick walls
• Veins: Carry to heart, thin walls, valves
• Capillaries: Exchange site

Chapter 2: Immunity

Types of Immunity

Innate (Non-specific)

• Skin and mucous membranes
• Phagocytes
• Inflammatory response
• Natural killer cells

Adaptive (Specific)

• Humoral: B cells → antibodies
• Cell-mediated: T cells → directly kill

Antigen and Antibody

• Antigen: Foreign substance (pathogen)
• Antibody: Protein produced against antigen

Immunization

• Active: Vaccine (own immune response)
• Passive: Ready-made antibodies

Allergies

Hypersensitivity to harmless antigens (pollen, food).

Autoimmune Diseases

Immune system attacks own body.

• Rheumatoid arthritis
• Diabetes Type I
• Multiple sclerosis

Chapter 3: Gaseous Exchange

Respiratory Surfaces

• Humans: Lungs (alveoli)
• Fish: Gills
• Plants: Stomata, lenticels

Human Respiratory System

1. Nasal cavity → filters, warms, moistens air
2. Pharynx → common passage
3. Larynx → voice box
4. Trachea → windpipe
5. Bronchi → branch to lungs
6. Lungs → contain alveoli

Mechanism of Breathing

• Inhalation: Diaphragm contracts, ribs rise, air in
• Exhalation: Diaphragm relaxes, ribs fall, air out

Gas Exchange

Transport

• O₂: 98% bound to hemoglobin (oxyhemoglobin)
• CO₂: 70% as bicarbonate, 23% bound to hemoglobin

Chapter 4: Nutrition and Digestion

Types of Nutrition

• Autotrophic: Make own food (plants)
• Heterotrophic: Get food from others

Digestive System

1. Mouth: Mechanical (chewing), chemical (salivary amylase)
2. Stomach: Mechanical (churning), chemical (HCl, pepsin)
3. Small Intestine: Main digestion and absorption
4. Large Intestine: Water absorption, feces formation

Enzymes

• Salivary Amylase: Starch → Maltose
• Pepsin: Proteins → Peptides
• Trypsin: Proteins → Amino acids
• Lipase: Fats → Fatty acids + Glycerol
• Maltase: Maltose → Glucose

Vitamins and Minerals

• Vitamin A: Vision
• Vitamin C: Immunity, collagen
• Vitamin D: Calcium absorption
• Iron: Hemoglobin
• Calcium: Bones, teeth

Chapter 5: Homeostasis

Osmoregulation

Water and salt balance.

Excretory System

• Kidneys: Filter blood, produce urine
• Ureters: Urine to bladder
• Bladder: Store urine
• Urethra: Remove urine

Nephron

1. Filtration: At Bowman's capsule
2. Reabsorption: In proximal tubule (glucose, amino acids, water)
3. Secretion: In distal tubule (drugs, H⁺, K⁺)
4. Concentration: In loop of Henle

Kidney Functions

• Remove waste (urea, creatinine)
• Regulate water balance
• Regulate pH
• Produce hormones (erythropoietin, renin)

Thermoregulation

• Hot: Sweating, vasodilation
• Cold: Shivering, vasoconstriction, piloerection

Chapter 6: Support and Movement

Skeleton

• Axial: Skull, vertebral column, ribs
• Appendicular: Limbs, girdles

Joints

• Ball and Socket: Hip, shoulder
• Hinge: Knee, elbow
• Pivot: Atlas-axis
• Gliding: Carpals, tarsals

Muscles

• Skeletal: Voluntary, striated
• Smooth: Involuntary, non-striated
• Cardiac: Heart, striated, involuntary

Muscle Contraction

Sliding filament theory: Actin slides over myosin using ATP.

Chapter 7: Nervous Coordination

Neuron Structure

• Dendrites: Receive signals
• Cell Body: Contains nucleus
• Axon: Conducts signal
• Myelin Sheath: Insulation (Schwann cells)
• Axon Terminals: Release neurotransmitters

Nerve Impulse

Resting potential: -70mV (more Na⁺ outside, more K⁺ inside).

Action potential: Depolarization → Repolarization.

Synapse

Neurotransmitters carry signal across synapse.

Central Nervous System

• Brain: Cerebrum (conscious), Cerebellum (balance), Medulla (vital functions)
• Spinal Cord: Reflexes

Reflex Arc

Receptor → Sensory neuron → Interneuron → Motor neuron → Effector

Chapter 8: Chemical Coordination

Endocrine Glands

Pituitary

Master gland. Produces growth hormone, TSH, FSH, LH, ADH.

Thyroid

Thyroxine (metabolism), Calcitonin (blood calcium).

Pancreas

Insulin (lowers blood sugar), Glucagon (raises blood sugar).

Adrenal

Adrenaline (fight or flight), Cortisol (stress).

Gonads

Testosterone (male), Estrogen/Progesterone (female).

Hormone Mechanism

• Second Messenger: cAMP (peptide hormones)
• Direct Gene Activation: Steroid hormones