Anatomy

Question 1

What are the functions of skeletons?

Answer 1

Support

Protection

Movement

Question 2

What are the three types of skeleton?

Answer 2

Hydrostatic

Exoskeleton

Endoskeleton

Question 3

What is a hydrostatic skeleton and what does it need?

Answer 3

A fluid filled sac under pressure

Organism must live in aquatic/moist environment

Question 4

What are the main features of hydrostatic skeletons?

Answer 4

Organs are situated internally and are protected by fluid - anchored by connective tissue

Muscles act on the sac to allow movement

Question 5

How do hydrostatic skeletons undergo locomotion?

Answer 5

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

Question 6

What are setae?

Answer 6

Bristles underneath the organism

Used to grip substrate as the body moves forward

Question 7

What is an exoskeleton?

Answer 7

Hard outer casing that provides support and protection

Question 8

What are different exoskeletons made from?

Answer 8

Arthropods are made from chitin

Molluscs are made from calcium carbonates

Question 9

What is the problem with endoskeletons and how is this overcome?

Answer 9

The organism cannot grow

Must be shed and replaced by ecdysis

Question 10

What are the disadvantages of ecdysis?

Answer 10

Energetically costly

Leaves individual vulnerable as the new skeleton hardens

Question 11

Do muscles attach inside or outside the animal in exoskeletons?

Answer 11

Inside

Question 12

What do endoskeletons comprise of?

Answer 12

Bones, muscles, tendons and ligaments

Question 13

How do endoskeletons allow movement?

Answer 13

Multiple bones work together

Muscles attach to bone using soft tissue

Question 14

What are ligaments made from?

Answer 14

Connective tissue - which are made from extracellular matrix

Question 15

What are tendons made from and why are they needed?

Answer 15

Made from keratin and hold blood supply etc

Also attach ligaments to the bones

Question 16

Where do biceps attach?

Answer 16

Top of the humorous and bottom of the radius

Question 17

Where do triceps attach?

Answer 17

Bottom of the humorous and top of the ulnar

Question 18

What do male mantis shrimp reflect?

Answer 18

Circular polarised light

Question 19

How many bones and muscles to humans have?

Answer 19

206 bones

Over 650 muscles

Question 20

What is cartilage?

Answer 20

Made of collagen fibres embedded in a solid gel matrix

If need something to have flexibility, cartilage is used

Question 21

What is bone?

Answer 21

Framework of collagen filled in with calcium phosphate

Gives strength and resilience

Question 22

What are the two types of bone marrow?

Answer 22

Yellow = fatty tissue

Red = blood cell production and O cells

Question 23

What are the types of bone?

Answer 23

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

Question 24

What are types of bone weight in percentage?

Answer 24

Compact bone is ~80%

Spongey bone is ~20% (has larger SA)

Question 25

What allows good blood supply to bones?

Answer 25

Periosteum

Also allows anchoring points

Question 26

Main features of osteoclasts?

Answer 26

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)

Question 27

Main features of osteoblasts?

Answer 27

Small cells

Single nuclei

Work in teams

Forms/re-shapes the bone

Question 28

What are the main features of osteocytes?

Answer 28

Formed from osteoblasts

Sit inside the bone

New bone forms around them

Connect to one another via branches

Sense damage and direct repair