Chapter 17 / 17.1 Types of Movement

Chapter 17: Locomotion and Movement

Movement is a key feature of all living things! 🌱🐾 Plants and animals show many types of movement.
Examples:
- Protoplasm streaming in Amoeba (unicellular organisms)
- Cilia, flagella, or tentacle movements in many organisms
- Human movements: limbs, jaws, eyelids, tongue
When movement changes an organism’s place/location (e.g., walking, running, swimming), it’s called locomotion 🚶‍♂️🏊‍♀️.
Key idea: All locomotion is movement, but NOT all movement is locomotion! (e.g., chewing food moves your jaw but doesn’t change your location).
Locomotion helps animals find food, shelter, mates, breeding grounds, good climates, or escape predators 🐾🌧️.

Amoeboid Movement:
- Seen in specialized cells like macrophages and leucocytes (white blood cells).
- Happens using pseudopodia (temporary protoplasm extensions) like in Amoeba.
- Involves cytoskeletal elements (e.g., microfilaments).
Ciliary Movement:
- Occurs in internal tubes lined with ciliated epithelium.
- Functions:
  - Trachea: Cilia push out dust/foreign particles from airways 🫁✨.
  - Female reproductive tract: Cilia help move ova (eggs).
Muscular Movement:
- Used for limb, jaw, and tongue movements 💪.
- Muscle contractions power locomotion in humans & most multicellular organisms.
- Requires teamwork between muscular, skeletal, and neural systems!

Muscles are mesoderm-derived tissues making up 40-50% of adult body weight.
Special properties:
- Excitability (respond to signals)
- Contractility (shorten force)
- Extensibility (stretch)
- Elasticity (return to original shape)

Skeletal Muscle:
- Attached to bones 🦴.
- Striped (striated) under a microscope.
- Voluntary control (you decide to move them!).
- Used for locomotion/posture changes (e.g., running, waving).
Visceral Muscle:
- Found in hollow organs (e.g., gut, reproductive tract).
- Smooth (non-striated) appearance.
- Involuntary control (automatic, e.g., digestion).
- Moves food through the digestive tract & gametes in genital tracts 🍲🔁.
Cardiac Muscle:
- (Mentioned as a type, but details not in this section).

Movement vs. Locomotion: Locomotion always changes location; other movements don’t.
3 human cell movements: Amoeboid (immune cells), ciliary (trachea/ovaries), muscular (limbs).
Muscle types & control:
- Skeletal → striated + voluntary
- Visceral → smooth + involuntary
Muscle properties: Excitability, contractility, extensibility, elasticity.
Ciliary function: Clears airways & moves ova.