25 pages covering all 12 lectures. Provides an overview of all body systems and goes into detail on the urinary, skeletal, integumentary, cardiovascular, digestive and muscular systems. Also covers the visual and hearing system.
(I achieved a score of 20.6/78.6%/first in this module)
Levels of Organisation:
1. Chemical level – atoms -> molecules ->
2. Cellular level ->
3. Functional tissue level ->
4. Organ level ->
5. Functional System level – completes 1 overall function
6. Organism level
Body Systems:
1. Integumentary System: skin + accessory organs e.g. hair, sweat glands, oil glands
➔ Protects internal organs from external conditions e.g. UV light, microorganisms, chemicals
➔ Water retention – sweat glands
➔ Temperature regulation – sweat glands = evaporative cooling, hairs on skin = erect/unerect,
➔ Waste elimination – sweat glands = lose electrolytes through sweating
➔ Produces vitamin D – absorbs calcium from being in contact with UV light
➔ Detects sensations with NS – hot, cold
2. Skeletal System: bones, joints + cartilage
➔ Supports + protects organs + tissues
➔ Muscle attachments to skeleton allow movement
➔ Bone marrow cells produce red blood cells
➔ Stores minerals in red bone marrow e.g. calcium + phosphorous
➔ Stores lipids in yellow bone marrow
3. Muscular System: skeletal muscle
• Under voluntary control
➔ Enables movement
➔ Stabilises body position – walking on 2 feet uses less energy
➔ Generates heat – shivering = muscles contract involuntary to generate heat
4. Cardiovascular System: blood, heart, blood vessels
➔ Blood transports substances – gases, nutrients, waste – urea, hormones
➔ Temperature regulation - vasodilation
➔ Water content regulation – drinking fluid changes pcy -> remove excess water
➔ Defence against disease – white blood cells
➔ Tissue repair – blood clots
5. Lymphatic + Immune System: lymphatic fluid, lymphatic vessels, lymph nodes, bone marrow,
spleen, thymus, tonsils
• Lymphatic fluid comes from blood – excess fluid stuck in tissue when being transported
➔ Returns proteins + fluid to blood
➔ Carries lipids from Gastro Intestinal tract to blood
➔ Protects against disease + cancer – WBC detect pathogens from blood
➔ Tonsils – white blood cells detect inhaled pathogens
➔ Spleen – filter for blood
➔ Thymus – where white blood cells mature + develop
,6. Endocrine System: hormone-producing glands e.g. hypothalamus - ADH, pituitary, thymus =
thymosin, thyroid gland = thyroxine, adrenal gland = aldosterone, pancreas, ovaries, testes…
➔ Releases hormones from glands to have specific effects on target organs
➔ Maintain homeostasis
➔ Co-ordinate range of body functions
7. Nervous System: brain, spinal cord, nerves, special sense organs = eyes, ears
➔ Generate nerve impulses to regulate body activities
➔ Detects stimuli + responds
➔ Stimuli = baroreceptors, chemoreceptors, thermoreceptors, osmoreceptors -> homeostasis
➔ Responses = Initiates muscle contraction, gland secretion
8. Respiratory System: lungs, air passages, pharynx = throat, larynx = voice box, trachea = connects
lungs + larynx, bronchioles, alveoli
➔ Gaseous exchange
➔ Regulates acid-base balance within body – regulates CO2 levels –
CO2 + H20 <-> H+ + HCO3- <- Bicarbonate ion = buffer
➔ Enables sound production when air passes through vocal cords inside larynx
9. Digestive System:
• Organs of GI tract = mouth, pharynx, oesophagus, stomach, small + large intestines +
• Accessory organs = salivary glands, gall bladder, liver, pancreas
➔ Physical breakdown of food = chewing + churning of stomach
➔ Chemical breakdown of food = enzymes
➔ Absorbs nutrients from food
➔ Eliminates solid waste from food which can’t be absorbed
10. Urinary System: kidneys -> ureters -> bladder -> urethra
➔ Makes, stores + eliminates urine
➔ Eliminates metabolic waster
➔ Regulates volume + chemical composition of blood
➔ Maintains acid-base balance of body fluids (pH -> enzyme denaturation -> metabolic death)
➔ Regulates production of RBC = kidneys secrete erythropoietin protein -> increases RBC
production
11. Reproduction System: ovaries, uterus, fallopian tubes, vagina + testes, epididymis, vas deferens,
penis
➔ Gamete production
➔ Hormone release
Regulates reproduction + associated body changes during puberty
L2 – Tissue Types + Structures
Tissue: a group of similar cells that usually have common embryonic origins + function together to
perform specialise functions
Embryo Tissues:
Inside endoderm -> epithelial cells
Middle mesoderm -> muscle tissue, epithelial cells, connective tissue
Outside ectoderm -> muscle tissue, epithelial cells
, Cell Junctions: connect cells in tissues together
Cell Junctions:
a) Tight Junction:
• Forms impermeable seals between adjacent cells
• Run continuously around cell circumference
• Impermeable barrier – water, pathogens, virus – cant
enter
• Mostly in epithelial cells e.g. skin
• Made of transmembrane protein
b) Adherens Junction:
• Mechanical role = hold cells together to resist strains + stresses -> cells
don’t get pulled open
• Adhesion belt: cadherin = transmembrane protein connects internally to
actin = microfilament
• Spread stresses through whole cell
• Part of cytoskeleton
• Doesn’t prevent substance exchange
c) Desmosome Junction:
• Holds cell together
• Confined to small regions around adjacent cells
• Cadherin joins adjacent cells together in intracellular space
• Keratin = intermediate filament -> connects to desmosome junctions
➔ Stresses spread throughout whole tissue
d) Hemidesmosome:
• Resists cells being pulled off basement membrane
• Integrin = transmembrane protein – connects plaque to basement
membrane
• Keratin = intermediate filament
e) Gap Junction:
• Forms pore between adjacent cells
• Allows cell-cell communication
• Allows movement of ions + small molecules e.g. ATP
• Each cell has 6 connexons = join in intercellular space
• Cells electrically coupled together
➔ Electrical signal delivered to cardiac muscle
gets passed onto adjacent cells allowing heart to contract
Tissue Types:
1. Nervous Tissue:
• Detects internal + external changes in environment + acts to
maintain homeostasis
• Responsible for detection of signals, cognition + self-awareness
Cell Types:
a. Neurons: generate + conduct nerve impulses
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