Support and Movement Flashcards
Why are hollow tubes used as part of support systems?
Hollow tubes are stronger than solid tubes of equal mass.
How is support provided for plants?
Support is provided at a cellular, tissue and gross level.
They probably have their own equivalent of like the Samaritans as well.
What is turgor pressure? Whats is its benefit to the plant?
Turgor pressure is the cell vacuole applying pressure to the cell wall, which means the plant stays upright so can photosynthesise more efficiently.
What is the basic stem morphology of a plant? There’s 4 main sections.
Pith.
Vascular bundles.
Cortex.
Epidermis.
What cells make up pith?
Parenchyma cells.
Whats the function of parenchyma cells, in a plant?
They possess thin cell walls which allows the cells to expand in response to increased fluid storage in the vacuole.
Whats the function of pith?
To store essential nutrients.
What cells make up cortex?
Collenchyma cells and some parenchyma cells.
How does the structure of collenchyma cells relate to their function?
They have thicker cell walls as they are used less for storage and more to allow the plant to flex and move in the wind without breaking.
What is the function of the vascular bundles?
These contain xylem and phloem and are thickened with lignin. Sclerenchyma surrounds the bundles to ensure the plant returns to its original shape after deformation.
What is the function of the primary root?
To provide anchorage and stability.
How many primary roots are found in a plant?
Usually just one.
What is the function of the lateral roots?
To absorb water and dissolved minerals.
What are the 3 types of animal skeleton?
Endoskeleton.
Exoskeleton.
Hydrostatic skeleton.
What is the basic structure of a hydrostatic skeleton?
A capsule of fluid surrounded by 2 muscle layers running perpendicular to each other.
What are the 4 main components of a hydrostatic skeleton which allows the animal to move?
Fluid filled cavity.
Circular muscles.
Longitudinal muscles.
Surface bristles.
How do circular and longitudinal muscles allow an animal with a hydrostatic skeleton to move?
Circular muscles elongate and narrow the body; longitudinal muscles shorten and thicken the body.
What is the function of the fluid filled cavity in hydrostatic skeletons?
It acts as a rigid column on which muscles can act.
What is the function of the surface bristles in animals with a hydrostatic skeleton?
They prevent backward sliding.
What is the function of an exoskeleton?
To provide strength and mobility.
What polysaccharide makes up most exoskeletons? What are it’s properties?
Chitin because it is both light and strong, especially when mineralised.
What are the limitations of an exoskeleton?
Size limiting.
Organism has to go through ecedysis (moult) as the exoskeleton doesn’t grow in line with the body.
What are the two types of endoskeleton?
Cartilaginous and bony.
Why does cartilage have to be thin?
Because it is avascular.
What are the benefits of a cartilaginous skeleton?
It is efficient to produce, light and more flexible than bone.
How are bony skeletons produced?
They develop from a cartilaginous skeleton as an embryo.
What are the benefits of a bony skeleton?
Greater strength to provide rigid support against gravity and can act as levers.
What is a key benefit of a bony endoskeleton? Think about whether it is a constant structure.
The skeleton is dynamic as it can respond to physiological activity. Bones if used in a certain way will change to better suit that purpose.
What are the 5 classes of bone?
Long bones. Short bones. Flat bones. Sesamoid bones. Irregular bones.
What is the function of long bones?
To act as levers.
What is the function of short bones?
To provide strength.
What is the function of flat bones?
To provide a surface for muscle attachment.
What is the function of sesamoid bones?
To develop within a tendon and increase insertional angle eg in the knee joint.
What are the 2 structures of bone?
Spongy and compact bone.
What is the name given to the holes in spongy bone? How are they arranged?
Trabeculae are aligned along lines of principle stress - Wolff’s Law.
What are the 3 cell types that make up bone?
Osteoblasts, osteoclasts and osteocytes.
What are osteoblasts and what is their function?
Immature bone cells found on bone surfaces. They secrete organic bone matrix to form new bone.
What are osteoclasts and what is their function?
Bone cells found in the endosteum which secrete acids and enzymes to remove old bone.
What are osteocytes and what is their function?
These are mature bone cells and possess a sense loading ability. This means the bone will strengthen if put under increased stress.
What is osteopetrosis?
When osteocytes think the skeleton is lighter than it is, resulting in an unnecessary increase in bone mass.
What makes up bone matrix?
67% hydroxyapatite
33% collagen + other proteins
By what age are all your bones fused?
Around 30.
What are sutures?
Fused joints resulting in bones joining together.
What makes up the axial skeleton?
Skull, vertebral column, ribs and sternum.
What are the 4 types of vertebrae that make up the vertebral column?
7 cervical.
12 thoracic.
5 lumbar.
1 coccyx.
How many pairs of ribs are there? How many are floating/false ribs?
12 rib pairs. 7 true pairs, 5 false pairs.
What are the 3 classes of joint?
Fibrous, cartilaginous and synovial.
What are the characteristics of fibrous joints?
Most immobile joint type. Dense fibrous connective tissue.
What are the characteristics of cartilaginous joints?
Two types, one with hyaline cartilage and one with fibrocartilage. Hyaline = less flexible. 1° cartilaginous = less flexible.
What are the characteristics of synovial joints?
Freely mobile. Bone ends covered in articular cartilage. Joint cavity containing synovial fluid. Enclosed in an elastic joint capsule.
What are the 3 muscle types?
Skeletal, cardiac and smooth.
Muscles have ends. What are the terms given to these ends and how are they chosen?
The origin = the stationary end.
The insertion = the more mobile end.
What is a biarticular muscle?
A muscle that crosses more than one joint such as the hamstrings.
What are the characteristics of muscles in a parallel arrangement?
Weak but a large range of movement.
What are the characteristics of muscles in an unipennate arrangement?
Stronger than parallel but a shorter range of movement.
What are the characteristics of muscles in a bipennate arrangement?
Strong but a short range of movement.
What are the characteristics of muscles in a multipennate arrangement?
Strongest muscle arrangement but shortest range of movement.
What do tendons link?
Muscles to bones.
What is isotonic muscle contraction?
Muscle tension remains constant, the muscle’s length changes.
What is isometric muscle contraction?
The muscle contracts but doesn’t change length.
What is concentric muscle contraction?
Muscle tension increases as the muscle shortens.
What is eccentric muscle contraction?
Muscle tension increases as the muscle lengthens.
Which muscle generates the basic movement?
The agonist.
Which muscle controls the movement?
The antagonist.
