Search results for: 'plant system'

Watch Later 2:15

Coaductile pathway, Timing of contraction signal & Conduction system and ECG

By: HWC, Views: 6867

• When the system is healthy, the signal to contract the entire conduction system originates in the SA node - known as the heart's pacemaker. • The SA node triggers contraction because it depolarizes at a faster rate than other parts of the conduction system. • The wave of excitation fr...

Watch Later 1:43

Polysaccharides

By: HWC, Views: 6197

More complex sugars are called polysaccharides (from "poly" meaning "many" and "saccharum" meaning "sugar"). Many things in nature are made of polysaccharides. Here we show one of the polysaccharides in corn, another in wood, and another in the exoskeletons of insects like grasshoppers. How are a...

Watch Later 1:22

Major Elements in Biological Molecules: Carbohydrates

By: HWC, Views: 6194

Carbohydrates include simple sugars (monosaccharides) as well as large polymers (polysaccharides). Glucose is a hexose, a sugar composed of six carbon atoms, usually found in ring form. A starch macromolecule is a polysaccharide composed of thousands of glucose units. Glucose molecules can be ...

Watch Later 1:20

Carbohydrate digestion - mouth and stomach & pancreas and small intestine

By: HWC, Views: 6400

• Digestion of complex carbohydrates (starches and glycogen) involves: • Amylases produced by the salivary glands and pancreas. • Brush-border enzymes in small intestine. • In the mouth, amylase from the parotid and submandibular salivary glands begins carbohydrate digestion. �...

Watch Later 1:10

Hormonal regulation of blood pressure - RAA system

By: HWC, Views: 7093

■ Long-term regulation of MABP is under hormonal control. • Hormones that affect blood pressure and volume: the renin-angiotensin-aldosterone (RAA) system, antidiuretic hormone (ADM), and atrial natriuretic peptide (ANP). ■ Most important hormonal regulator of MABP. Activated by drop in...

Watch Later 1:08

Carbon fixing adaptations Animation

By: HWC, Views: 329

Different plants trap carbon by different pathways. Most C3 plants evolved in moist, temperate zones. On hot dry days they close their stomata to conserve water and oxygen accumulates. Under these circumstances, the enzyme rubisco uses oxygen in an inefficient reaction that competes with t...

Watch Later 0:23

Components of the Nervous System

By: Administrator, Views: 384

The nervous system is the part of an animal that coordinates its actions by transmitting signals to and from different parts of its body. The nervous system detects environmental changes that impact the body, then works in tandem with the endocrine system to respond to such events. Nervous tissue...

Watch Later 2:12

Depolarization of the SA node, Action potentials of the myocardium & ANS effects

By: HWC, Views: 6495

• A typical contractile cell in the myocardium has a resting membrane potential. • The resting membrane potential of cells in the SA node is not fixed, and is known as the pacemaker potential. • The action potential of a healthy SA nodal cell has three parts: • Pacemaker potential: ...

Watch Later 2:09

Ventilation - phases and driving forces

By: HWC, Views: 6630

Respiration is the exchange of gases between the atmosphere, blood, and cells The combination of 3 processes is required for respiration to occur Ventilation (breathing) External (pulmonary) respiration Internal (tissue) respiration The cardiovascular system assists the respiratory system b...

Search Results