HB EXAM CRAM

What is mucosa

The inner most layer of the stomach, it’s a mucous membrane that lines the stomach and protects it from the harsh acidic environment

How does bone tissue provide movement of materials

Diffusion

caniliculi contains blood vessels which link to the central canal which contain arteries

Stomach lining and digestive juices

Pepsinogen = pepsin in highly acidic environments pH 2-3

Mucus is neutralising, making hydrochloric acid not break down the stomach wall

Secretion of gastric juice is regulated as its only released when food enters the stomach

Has an epithelial lining

Contractibility

Refers to muscles ability to respond to stimulus by shortening, producing force

Extensibility

Muscles ability to be stretched

Elasticity

Muscles ability to return to its original length after stretching

Catabolism

Break DOWN big molecules into smaller ones which releases energy

Anabolism

BUILD up smaller units into larger molecules which requires energy

Enzymes

Biological catalysts are proteins that are specific for a particular substrate, the active site is a complimentary shape to the substrate, allowing them to fit together

Optimal temp is 36°C, Optimal pH is 7, pepsin is 2,3. Body regulates enzyme concentration

If these factors go above the enzyme will denature where an enzyme looses its shape

Steps of muscle contraction

1. Muscle is stimulated by a nerve

2. Binding site are present as tropmyosin / toponin acts as a barrier

3. ATP binds to myosin heads, priming them

4. Calcium binds to troponin causing it to move, exposing chin binding site

5. Cross bridges form between myosin heads + actin binding sites (release of ATP)

6. Power stroke, actin filaments slide past myosin towards centre of sarcomere

7. Fresh ATP attached to myosin head, releasing them from binding sites and reprising them for another movement

Hyaline Cartilage

Closely packed collagenous fibres in matrix, so fine not distinguishable under light microscope STRENGTH W FLEXIBILITY

Rings of trachea

Elastic Cartilage

Conspicuous elastic fibres + collagenous fibres, similar to hyaline but not as closely packed, found in external ear

FLEXIBILITY

Fibrocartilage

Course appearance, parallel bundles of collagenous fibres

ABLE TO COMPRESS SLIGHTLY, eg intervetebreal discs of spinal column

Villus

Single 1 is 1mm long. Extend from a folded surface, suited for function of absorption, covered by a single cell

Villi path of absorption

Amino acids and simple sugars by active transport

Water + water soluble vitamins via diffusion

Fatty acids + glycerol diffuse into lacteal, along w fat soluble vitamins

What is pleura

A thin double membrane that covers the surface of the lungs (visceral pleura) and the other layer that lines the inside of the chest (parietal pleura), between the two layers is pleural fluid which holds lungs against chest wall and allows the lungs to slide across the chest when breathing

It also creates surface tension so lungs can expand

Leukocytes

WBC

Thrombocytes

Platelets

Transport of oxygen

97% on haemoglobin and 3% dissolved in plasma

Transport of carbon dioxide

22% on haemoglobin 70% as bicarbonate ions in plasma

Amylase

Enzyme that breaks down carbohydrates

Proteases

Enzyme that breaks down proteins

Lipases

Enzymes that break down lipids

Carbohydrate digestion stages

(Mouth) Salivary amylase = polysaccharides and disaccharides

(Duodenum) Pancreatic amylase = disaccharides

Disaccharidases = monosaccharides

Lipids digestion stages

(Duodenum) bile salts and lipase

Fatty acids and glycerol

Protein digestion stages

(Stomach) Pepsin = polypeptides

(Duodenum) trypsin (pancreatic protease)from pancreas’s and other enzymes break down it into peptides

Peptidase = amino acids

Mechanical digestion

The physical breakdown of food particles into smaller particles, not involving new substances being made. Aim is to increase SA of food

Chemical digestion

The break down of food via chemical reactions into smaller simpler molecules, small enough to be absorbed into the blood stream,

Involves use of enzymes

Small intestine 1st section

Duodenum

Small intestine 2nd part

Jejunum

Small intestine 3rd part

Ileum

Axial skeleton

Consists of bone around the centre of the body, erect posture. Skull vertebral column ribs sternum

Protects CNS + organs in the thoracic cavity

Appendicular skeleton

Bones of upper and lower limbs, facilitates movement and connects to axial

Clavicle, scapula. Pelvic girdle, pectoral girdle = articulation

Origin

End of muscle fixed to stationary bone

Insertion

Point of muscle that attaches to bone that allows the bone to move