The Machine that Repairs Itself Flashcards
Muscular Tissue
- Contracts to move
- Three types:
> Skeletal - voluntary, muscles attached to the skeleton
> Smooth - involuntary, in the walls of hollow visceral organs
> Cardiac - involuntary, in walls of the heart
Epithelial Tissue
- Covers all body surfaces, line body cavities, and hollow organs
- Major tissue in glands
- Protection, secretion, excretion, absorption, sensory reception, etc.
Connective Tissue
- Structure and support
- 6 types: dense, adipose, areolar, compact, blood, loose.
Skin: Epidermis
- Protection, secretion, and absorption
- Epidermis
> Consists mainly of cells called keratinocytes
> Epithelial-type tissue
Skin: Dermis
- Dermis
> Held together by collagen (gives skin flexibility and strength)
> Connective tissue layer
> Contains blood vessels, nerves, hair follicles, sweat glands, etc.
Skin: Sensations
Mechanoreceptors: - Pressure - Vibrations - Texture Thermoreceptors: - Temperature - Hot and cold receptors Pain receptors: - Detect pain or stimuli Proprioceptors: - Sense the position of different body parts in relation to each other and the surrounding environment
Structures of the Musculoskeletal System: Muscles
- Muscle fibres
- Give us the ability to constrict
Structures of the Musculoskeletal System: Bones
- Osteocytes
- Give us strength and structure
Structures of the Musculoskeletal System: Ligaments
- Fibrocytes (spindle-shaped cells)
- For stability at joints from bone to bone
Structures of the Musculoskeletal System: Cartilage
- Chrondocytes
- Elastic tissue that covers and protects long bones at the joints
- Main function is to connect bones together
Structures of the Musculoskeletal System: Tendons
- Fibroblasts
- Attach muscle to the bone
Skeletal Muscle: Contracting to Produce or Hold a Movement
- Concentric contraction: contracting
- Eccentric contraction: lengthening
- Isometric contraction: holding
Skeletal Muscle: Myosin and Actin
Two types of proteins that form contractile filaments in muscle cells. Myosin is a motor protein involved in muscle contraction. Actin is a protein that forms filaments, which are involved in muscle contraction.
Bones: Function
- Protection e.g. skull, ribs, etc.
- Longer bones for movement
- Dexterity - small bones in hands
- House hemopoietic stem cells
Bones: Bone Tissue
Bone tissue is connective tissue defined as a matrix made up of:
- Organic: approx. 20% collagen
- Inorganic: approx. 65-70% calcium
It can be compact or spongy.
Bones: Osteoblasts
Cells with only one nucleus that form new bone. Produce new bone - osteoid - which is made of bone collagen and other protein. The process is called ossification.
Bones: Osteoclasts
Multinucleated cells that reabsorb bones.
Cartilage: Hyaline
Translucent cartilage found on many joint surfaces. It provides support, flexibility and helps hold the body together.
Found mainly in the ribs, nose, larynx, and trachea.
Cartilage: Elastic
It provides support with moderate elasticity.
Found mainly in the larynx, pinna, and eustachian tube.
Cartilage: Fibrocartilage
Tough, very stringy tissue found mainly in the intervertebral discs and at the insertions of ligaments and tendons.
It helps fill in torn part of cartilage, although it is not a good substitute as it is tough.
Tendons
- Connect muscle to bone
- Outer sheath for protection and also anchors the tendon to the muscle and the bone
- Tendonitis can occur after repeating a movement many times
Ligaments
- Connects bone to bone
- Provide stability
- Like an elastic band
Joints
Where bones, ligaments, and cartilage come together.
Joints: Fibrous Joints
- Fixed/immovable joints
- Held together by tough fibre
- E.g. skull
Joints: Cartilagenous Joints
- Slightly moveable joints
- Held together by ligaments
- Joined by cartilage
- E.g. ribs
Joints: The Synovial Joint
- Freely moveable joints
- E.g. hips, shoulders and knees
Joints: Flexion and Extension
- Flexion: the angle at joint getting smaller
- Extension: the angle at a joint getting bigger
Phase of Tissue Healing: Inflammatory
It starts immediately and lasts a few days.
- Increasing blood flow to the area - allows nutrients, immune cells to get out, various growth factors secreted by cells
- Making the damaged tissue painful and tender - stops us from using the area to prevent more damage
Phase of Tissue Healing: Repair/Proliferation
It starts after a few days, lasts for a few weeks.
- Rapid cell division to replace damaged tissue
Phase of Tissue Healing: Maturation/Remodelling
It starts after a few weeks, may last for a couple of years.
- Remodelling and reorganisation to same as before the injury
- Whether damaged tissue will regenerate completely or leave a scar depends on tissue type (some cells don’t regenerate), and the degree and type of injury
Healing: Primary Intention
When damage is minimal e.g. minor cut
Healing: Secondary Intention
- Epithelial cells and laying down of scar tissue
- Scar tissue increases the strength
