Organ Systems || Earth & Life Science || SHS Quarter 4 Week 5

Scientific concepts and nature phenomena presented

Biological organization & homeostasis

• Question: How do complex organisms obtain raw materials for many trillions of cells?
• Core concept: Levels of organization in living things (unifying theme of biology).
• Body system: A group of organs working together for a common purpose.
• Interdependence: Body systems work together to maintain homeostasis (internal balance).

Organ systems (representative animals; structure–function ideas)

1) Skeletal system (support/protection)

Functions:

• Support and protection of internal organs
• Attachment sites for muscles
• Production of blood cells (implied)

Vertebrate examples:

• Fish: endoskeleton
• Tortoise: backbone connected to the shell
• Ostrich, frog, snake (vertebrates)
  • Example note: snake jaw flexibility helps swallow prey

Key numerical detail:

• Typical human bone count: ~206 (after development/aging)

Types:

• Endoskeleton (“inside”)
• Exoskeleton (“outside”)

---

2) Muscular system (movement/heat/posture)

Functions:

• Movement (with the skeletal system)
• Posture
• Produces heat

Quantitative detail:

• About 600–650 muscles (as stated)

Muscle types:

• Cardiac muscle (heart)
• Skeletal muscle
• Smooth muscle (e.g., stomach)

Structure hierarchy (as described):

• Muscle made of muscle fibers
• Bundles called fascicles
• Each muscle fiber contains smaller units (noted as myofibril/myofibran in subtitles)
• Mention of tendon connection and related connective structures

---

3) Digestive system (mechanical + chemical digestion; absorption)

Functions:

• Break down food
• Absorb nutrients for growth and maintenance

Process (step-by-step):

1. Mouth (mechanical digestion)
2. Tongue
3. Esophagus
4. Stomach (gastric juices; partial digestion)
5. Small intestine (main digestion + nutrient absorption)
6. Large intestine (water absorption; forms feces)

Accessory organs:

• Liver, gallbladder, etc.

Types:

• Complete digestive system (humans/higher animals): distinct mouth and anus
• Incomplete digestive system (e.g., jellyfish):
  • Gastrovascular cavity acts as both digestive space and waste exit

Jellyfish life-cycle trivia:

• Polyp stage → jellyfish stage (with tentacles)

Ruminant digestive adaptation:

• Cattle, sheep, goats, deer are ruminants
• Four-compartment stomach:
  • intake sequence: rumen → reticulum → omasum → abomasum
  • subtitles include “abomin/final processing”
• Purpose: process cellulose-containing plant material (implied)

---

4) Circulatory system (transport of nutrients, gases, hormones, wastes)

Main function:

• Transport nutrients, gases, hormones
• Remove wastes

Heart chamber comparisons (as stated):

• Fish: 2 chambers
• Amphibians (frogs): 3 chambers
• Mammals and birds: 4 chambers

Types:

• Open circulatory system:
  • Blood not enclosed in vessels
  • Blood pumped into a body cavity (hemocoel)
  • Example: insects (grasshopper)
• Closed circulatory system:
  • Blood pumped through vessels
  • Blood separated from interstitial fluid
  • Example: earthworms and higher animals

---

5) Respiratory system (gas exchange)

Function:

• Gas exchange between blood and environment via diffusion:
  • oxygen (O₂)
  • carbon dioxide (CO₂)

Representative strategies:

• External gills (mentioned, for an axolotl in subtitles)
• Internal gills (fish)
• Tracheal system (insects such as grasshopper/mantis):
  • Air enters/exits through spiracles
  • Tracheae → smaller tubes (trachioles) reaching cells
• Lungs (mammals; described as “developed/evolved”)

---

6) Excretory/urinary system + excretion concept

Function:

• Remove cellular waste, toxins, excess water (and excess substances)

Urinary system parts:

• Kidneys, ureters, bladder, urethra

Excretory system (broader definition):

• Includes the urinary system and other waste-removing organs like the skin (sweat/body wastes)

Kidney details:

• Nephrons filter blood
• Stated value: about 1.3 million nephrons per kidney
• Stated detail: kidneys filter about ~1 liter of blood per minute (as claimed in subtitles)

Invertebrate excretion examples (as listed):

• Flatworms: protonephridia
• Insects: Malpighian tubules
• Segmented worms (earthworms): metanephridia
• Subtitles also mention something like “plant/to plants” (unclear transcription)

---

7) Endocrine system (hormonal regulation via glands)

Concept:

• Endocrine glands secrete hormones internally
• Hormones deliver chemical messages to regulate:
  • metabolism
  • growth and development
  • tissue function
  • sexual function/reproduction
  • sleep
  • mood (as stated)
  • hormone imbalances

Major glands mentioned (subtitles):

• Pituitary gland: FSH and LH
  • follicle-stimulating hormone; luteinizing hormone
• Pineal gland: melatonin (controls biological clock)
• Thyroid gland: affects metabolic rate
• Adrenal glands: “fight-or-flight” response
• Pancreas: regulates blood sugar
• Ovaries and testes: reproductive hormones
• Brain: involved via nervous/endocrine interaction context

Note: A table/screen section connects glands to target functions (too many names to list fully beyond those above).

---

8) Nervous system (signal relay and control of behavior/movement)

Function:

• Relays signals controlling behavior, movement, and physiological processes

Division:

• Central nervous system (CNS): brain and brain stem (information processing)
• Peripheral nervous system (PNS): nerves/neurons; carries signals and responses

Representative animals:

• Hydra: nerve nets
• Flatworms: nerve cords and associative neurons
• Earthworms: central + peripheral nerves (described)
• Squid: more developed (including brain and “giant axon” mention)
• Grasshopper: brain connected to ventral nerve cords

---

9) Immune system (defense against pathogens)

Concept:

• Complex network of immune cells and proteins
• Protects against foreign invaders like viruses and bacteria (“germs”) and harmful materials

Three lines of defense:

• First line (physical + chemical barriers):
  • Skin
  • Mucous membranes (nose, etc.)
  • Secretions
• Second line (innate immune responses):
  • Phagocytic cells engulf pathogens
  • Natural killer cells
  • Antimicrobial proteins
  • Inflammatory response
• Third line (adaptive immunity):
  • White blood cells, especially lymphocytes
  • Antibodies
  • Antigen-presenting cells (subtitles mention macrophages and antigen-presenting cells)

---

10) Reproductive system (sex cells + sex hormones)

Functions:

• Produces sex cells and sex hormones

• Male: testes produce sperm

• Female: ovaries produce eggs

---

11) Integumentary system (external protection)

Components:

• Skin, hair, nails (as stated)

Functions:

• External covering
• Protection against:
  • infection
  • desiccation (drying out)
  • abrasion
  • radiation damage

---

Interactions among body systems (tandem relationships; activity outline)

The final activity explicitly connects systems in pairs, for example:

• Digestive + Muscular: food moved down the esophagus
• Urinary + Circulatory: kidneys filter materials out of the body
• Respiratory + Muscular: inhalation/exhalation relates to muscle activity
• Endocrine + Nervous: brain glands control functions via hormones
• Respiratory + Circulatory:
  • oxygen delivery to the bloodstream
  • removal of carbon dioxide
• Endocrine + Circulatory: adrenaline (“adrenaline rush”) increases heart rate during danger
• Digestive + Circulatory: nutrients transported from intestines via the circulatory system
• Endocrine + Skeletal: testosterone increases bone density in a growing male
• Skeletal + Circulatory: bone marrow produces red blood cells (immune response correction noted in subtitles)

---

Researchers or sources featured (at end)

• Marceli/Marcello Malpighi (Italian scientist): namesake of Malpighian tubules (also noted as “named after Italian scientist Marcel Fiji” in subtitles)
• News-Medical.net: referenced as a source for “three lines of defense”
• Department of Education (DepEd) / DepEd officials / DepEd modules: curriculum/module source (referenced throughout)

(No specific additional named scientists, authors, or institutions are clearly credited beyond those above.)