Anatomy Flashcards
What are the functions of skeletons?
Support
Protection
Movement
What are the three types of skeleton?
Hydrostatic
Exoskeleton
Endoskeleton
What is a hydrostatic skeleton and what does it need?
A fluid filled sac under pressure
Organism must live in aquatic/moist environment
What are the main features of hydrostatic skeletons?
Organs are situated internally and are protected by fluid - anchored by connective tissue
Muscles act on the sac to allow movement
How do hydrostatic skeletons undergo locomotion?
Have circular muscles that goes around the body
Have longitudinal muscles that go along the body
When circular muscles contracts and the longitudinal muscles relaxes the body becomes long and thin
When circular muscles relax and the longitudinal muscles contract the body shortens
What are setae?
Bristles underneath the organism
Used to grip substrate as the body moves forward
What is an exoskeleton?
Hard outer casing that provides support and protection
What are different exoskeletons made from?
Arthropods are made from chitin
Molluscs are made from calcium carbonates
What is the problem with endoskeletons and how is this overcome?
The organism cannot grow
Must be shed and replaced by ecdysis
What are the disadvantages of ecdysis?
Energetically costly
Leaves individual vulnerable as the new skeleton hardens
Do muscles attach inside or outside the animal in exoskeletons?
Inside
What do endoskeletons comprise of?
Bones, muscles, tendons and ligaments
How do endoskeletons allow movement?
Multiple bones work together
Muscles attach to bone using soft tissue
What are ligaments made from?
Connective tissue - which are made from extracellular matrix
What are tendons made from and why are they needed?
Made from keratin and hold blood supply etc
Also attach ligaments to the bones
Where do biceps attach?
Top of the humorous and bottom of the radius
Where do triceps attach?
Bottom of the humorous and top of the ulnar
What do male mantis shrimp reflect?
Circular polarised light
How many bones and muscles to humans have?
206 bones
Over 650 muscles
What is cartilage?
Made of collagen fibres embedded in a solid gel matrix
If need something to have flexibility, cartilage is used
What is bone?
Framework of collagen filled in with calcium phosphate
Gives strength and resilience
What are the two types of bone marrow?
Yellow = fatty tissue
Red = blood cell production and O cells
What are the types of bone?
Spongey bone - lightweight but has criss-cross structure to provide strength
Compact bone which surrounds spongey bone and has tight packed layers - also provides strength
What are types of bone weight in percentage?
Compact bone is ~80%
Spongey bone is ~20% (has larger SA)
What allows good blood supply to bones?
Periosteum
Also allows anchoring points
Main features of osteoclasts?
Large cells (2+ cells that have fused together)
Multiple nuclei
Re-shape bone and is formed from bone marrow
Dissolves bone to free calcium ions and minerals (help form new bone along with collagen)
Main features of osteoblasts?
Small cells
Single nuclei
Work in teams
Forms/re-shapes the bone
What are the main features of osteocytes?
Formed from osteoblasts
Sit inside the bone
New bone forms around them
Connect to one another via branches
Sense damage and direct repair
