Unit 4 Part 2 Flashcards
B3.2
Where do capillaries receive their blood from?
Arterioles, the smallest of arteries
What does an arteriole branch into w/in body tissue?
A capillary bed
Where will a single capillary bed drain its blood into?
Venule, the smallest vein
Why do blood cells line up in a single file when they enter a capillary bed?
B/c lumen (inside diameter) of each capillary is large enough to accommodate one cell at a time
What is a capillary composed of?
It is a small tube consisting of a single-cell thickness of inner and outer tissue
What is highly vascular tissue?
Metabolically active tissues enriched w/ capillary beds
Fenestrated capillaries?
Capillary beds that are designed to be even more permeable to substances than a regular capillary
What are fenestrations?
Small slits/ openings that allow significantly large molecules to exit/ enter the blood and allow increased movement of all molecules
Examples of fenestrated capillaries?
- Multiple small capillaries of the kidneys
- Areas of intestine where movement of molecules must be rapid
Adaptations of capillaries?
- Small inside diameter (lumen) = large surface area
- Thin wall = 1 cell thick, allows rapid exchange of materials by diffusion
- Permeable
- Fenestrations in some
What are capillaries?
small blood vessels which connect arteries to veins
What is the function of capillaries?
to exchange materials between the blood and cells
What do arteries do?
Receives blood from the heart and takes that blood to a capillary bed
What do veins do?
Receives blood from a capillary bed and takes that blood back to the heart
Why are arteries lined with a thick layer of smooth muscle and elastic fibres?
B/c blood the recieve from heart is under high pressure
What are arteries lined with?
a thick layer of smooth muscle and elastic fibres
Adaptations of arteries?
- Thick wall
- Proteins collagen + elastic in walls
- Smooth muscle
- Narrow lumen
What are the smooth muscles controlled by?
Autonomic nervous system (ANS)
What does the Autonomic nervous system do?
Controls those functions in your body that are necessary but not controlled
What do the thick walls of arteries do?
Allows arteries to withstand high blood pressure
What do the proteins collagen and elastin do?
Allow arteries to keep blood moving and withstand the high pressure
- When blood is pumped into the artery they will stretch to allow blood vessels to accommodate high blood pressure
Where can you measure your pulse rate?
- The carotid artery = Side of trachea in neck
- The radial artery = On wrist, pulse should be felt 2cm upwards from thumb base
Adaptations of veins?
- Thin walls
- Large lumen
What do thin walls in veins do?
Allows veins to be compressed by skeletal muscles
- compression moves blood back to the heart
What does a large lumen in veins do?
Allows veins to carry a large volume of blood
What are coronary arteries?
Arteries that supply blood to cardiac muscle
What is plaque in the lumen of arteries?
A build up of cholesterol and other substances in lumen
What is an occlusion?
The restriction in blood flow caused by a plaque
What is transpiration?
evaporation of water in leaves through open stomata
Where is water in plants located?
In the air spaces of the spongy metophyll layer
Cohesion tension theory?
When water is drawn out of the xylem,moving through cell walls, by capillary action, to replace water lost by mesophyll cells
- The loss of water in the xylem creates a negative pressure in the leaf.
How are xylem tubes formed?
when cells are stacked on top of each other creating cell walls, plasma membrane, organelles. Once dead, hollow cells have no end cell walls - forming a long hollow tube through them
What is lignin?
Provides resistance to collapse of tubes b/c of tension created by transpiration
What is the function of an epidermis in a plant stem and root?
Stem: Prevents water loss + provides protection from microorganism
Root: Grows root hair that increase the surface area for water uptake
What is the function of a cortex in a plant stem and root?
Stem and root: An unspecialized cell layer that sometimes stores food reserves
What is the function of a xylem in a plant stem and root?
Stem: Transport tubes that bring water up from the roots
Root: Transport tubes for water and minerals starting in roots
What is the function of a phloem in a plant stem and root?
Stem: Transports carbohydrates usually from leaves to other parts of the plant
Root: Transport tubes that receive sugars from leaves
What is the function of a vascular bundle in a plant stem and root?
Stem: Contains multiple vessels of both xylem and phloem
Root: Area in centre of root containing xylem and phloem
What is tissue fluid?
The fluid that surrounds cells, allowing the exchange of materials between the blood and cells
What is pressure filtration?
The release of tissue fluid
What is a venule?
The smallest of all veins
Why is the pressure of on the side of the venule low?
B/c it is further away from direct pulse of the heart
What does release of tissue fluid include?
- Blood leaves an artery (arteriole) at high pressure, and enters a capillary.
- The high hydrostatic pressure of the blood filters blood plasma through gaps in the capillaries, forming tissue fluid
What molecules diffuse through facilitated diffusion?
Molecules that have natural concentration gradient like oxygen, carbon dioxide, and glucose
What are lymphatic capillaries?
Small tubes that some tissue fluid enter
What are lymph?
Fluid that enters lymphatic capillaries
Pulmonary circulation (right side)?
The side of the heart that is used to pump the blood to capillaries in the lungs for reoxygenation
Systemic circulation (left side)?
The side of the heart that pumps returned blood out to capillaries in body tissues to supply oxygen to where its needed
What do arterioles do?
Very small blood vessels that carry blood from arteries to tissues and organs
Adaptations of the heart?
- Cardiac muscle
- A pacemaker
- Atria
- Ventricles
- Atrioventricular valves
- Semilunar valves
- Septum
- Coronary vessels
Cardiac muscle in heart?
Allows heart to contract to create high pressure
- Cardiac muscle for the left ventricle is much thicker than the right
- Left ventricle requires high pressure to move blood around the body
A pacemaker/ Sinoatrial node?
Initiates and controls the rate of heart beat.
Atria?
receive blood from the body and lungs
Ventricles?
Thick muscular chambers that pump blood out under pressure to lungs and body tissue
Atrioventricular valves?
Located between atria and ventricles that close each heart cycle to prevent backflow of blood into atria
Semilunar valves?
Valves that close after the surge of blood into pulmonary artery or aorta to prevent backflow of blood into ventricles
Septum?
Wall of muscular and fibrous tissue that separates the right side of heart from left
Coronary vessels?
Blood vessels that supply oxygenated blood to heart muscle
