Block1: Foundations Of Medicine

Question 1

Primary function of cardiovascular system and its organs

Answer 1

To transport nutrients, oxygen and waste products to and from the cells of the body

Organs- heart and blood vessels

Question 2

What is the pulmonary circuit

Answer 2

A short loop in which blood is first pumped to the lungs to be oxygenated before flowing back to the heart

Question 3

What is The systemic circuit

Answer 3

A much larger loop in which freshly oxygenated blood is pumped around the entire body and back again via a vast interconnected network of arteries, capillaries and veins.

Question 4

What do the arteries do

Answer 4

Carry blood away from the heart and towards capillaries
The pressure is high due to their relative proximity to the heart

Question 5

What do the capillaries do

Answer 5

Connect the smallest arteries (arterioles) with the smallest veins (venules) and are involved in the exchange of gases and fluids between tissues and the blood
Capillary walls consist of a semi permeable simple squamous epithelium and a thin basement membrane

Question 6

What do the veins do

Answer 6

Carry blood away from capillaries and towards the heart

Question 7

Subdivision of arteries and eg

Answer 7

1. Large elastic arteries like the aorta
2. Medium muscular arteries eg femoral artery
3. Small arteries and arterioles

Question 8

What are large elastic arteries

Answer 8

Like an aorta are found nearest to the heart
Their walls contain layers of elastic fibres- a feature which helps maintain a steady flow of blood throughout the body

Question 9

What are medium muscular arteries

Answer 9

Lie distal to elastic arteries and are the main distributors of blood to organs and organ systems. Contraction of smooth muscle fibres in their walls help regulate blood flow according to the demands of the organs

Question 10

What are small arteries and arterioles

Answer 10

Have narrow linen but thick walls also containing smooth muscle
The dilation and contraction of arterioles help regulate systemic blood pressure

Question 11

The 3 layers of arteries and veins

Answer 11

Known as tunicae
1. Tunica intima
2. Tunica media
3. Tunica external/adventitia

Question 12

What is Tunica intima

Answer 12

Tunica intima - think of this innermost layer as being in intimate’ contact with the blood in the lumen. Lined with simple squamous epithelium.

Question 13

What is Tunica media

Answer 13

Tunica media - this middle layer consists primarily of concentric bands of smooth muscle.
Contraction of the smooth muscle cells decreases the diameter of the vessel, a process known as vasoconstriction.

Question 14

What is Tunica externa/adventitia

Answer 14

Tunica externa/adventitia - this outermost layer strengthens the vessel and helps anchor it to surrounding structures. In larger vessels, the tunica adventitia contains vasa vasorum (‘vessels of the vessels’) which supply blood to the outer parts of the vessel wall.

Question 15

What are the 3 categories of veins

Answer 15

1. Large
2. Medium
3. Venules

Question 16

What are large veins

Answer 16

Large veins have a well-developed tunica adventitia (connective tissue surrounding blood vessels, see Station 2) and are large, such as the inferior vena cava.

Question 17

What are medium veins

Answer 17

Medium veins frequently accompany medium arteries and have venous valves where needed to stop backflow of blood.

Question 18

What are venules

Answer 18

Venules drain capillary beds and are only visible with magnification.

Question 19

Description of the large intestine/colon

Answer 19

Distinctively shaped organ whose ascending. transverse and descending parts frame the small intestine. Functions primarily to absorb water from digested matter, resulting in semisolid waste.

Question 20

Description of pharynx

Answer 20

A muscular passageway that is found posterior to the oral and nasal cavities, and proximal to the oesophagus and larynx.

Question 21

Description of oral cavity

Answer 21

This multi-purpose cavity represents the start of the Gl tract. Contains the structures needed to grind, compress, lubricate, and taste foods prior to swallowing.

Question 22

Description of stomach

Answer 22

An expandable J-shaped organ.
Smooth muscle contractions help churn and squeeze its contents into chyme (an acidic fluid containing partially digested food).

Question 23

Description of oesophagus

Answer 23

A tube of smooth muscle. Its peristaltic (wave-like) contractions help conduct swallowed food from the pharynx to the stomach.

Question 24

Description of small intestines

Answer 24

Measuring approximately 6m, this is the longest and most convoluted part of the Gl tract. Most enzymatic digestion and nutrient absorption occurs here.

Question 25

The liver

Answer 25

The liver produces bile which helps the body digest and absorb lipids. It also processes absorbed nutrients and removes ingested toxins from the blood.

Question 26

The gallbladder

Answer 26

The gallbladder stores and concentrates bile produced by the liver, contracting to release its contents into the first part of the small intestine (the duodenum) when lipids are detected.

Question 27

The pancreas

Answer 27

The pancreas is a slender gland featuring head, body, and tail regions. Its secretions are collected via a long, central duct before being released into the duodenum. There, they help break down sugars, lipids, and starches.

Question 28

The salivary gland

Answer 28

The salivary glands are multiple small organs located close to the oral cavity. Their watery secretions (saliva) enter the mouth to begin breaking down food.

Question 29

Adaptations of small intestines

Answer 29

• Its length provides a huge surface area for absorption (despite its name, the small intestine is the longest part of the gastrointestinal tract)
It is lined with finger-like projections (villi) to maximise absorptive capacity. These projections are covered by a simple columnar epithelium of absorptive cells.

Question 30

Microscopic features of large intestines

Answer 30

• A simple columnar epithelium without villi.
• Intestinal glands (these will be covered in future sessions, focus on epithelia for now)

Question 31

The kidneys

Answer 31

The kidneys are paired organs which primarily filter and purify the blood, removing excess fluid, toxins, and waste products as urine.

Question 32

Ureters

Answer 32

The two expandable ureters carry urine from each kidney to the urinary bladder with contractions of their smooth muscular walls.

Question 33

Urinary bladder

Answer 33

The urinary bladder is an expandable sac which stores urine until it can be voided conveniently. Smooth detrusor muscle in the bladder wall contracts to help empty the bladder and return it to its usual size.

Question 34

Urethra

Answer 34

The urethra is a tube which allows urine to be drained out of the bladder and excreted from the body. Urethral sphincter muscles help prevent the accidental leakage of urine.