Biology Final End of Year Exam

Question 1

Histology of the alimentary canal

Answer 1

Lumen outward - Muscosa, sub mucosa, muscularis externa, serosa

Question 2

4 tunics of the GI Tract

Answer 2

Lumen outwards :
Mucosa
Sub mucosa
muscularis externa, serosa

Question 3

Lumen outwards :
Mucosa
Sub mucosa
muscularis externa, serosa

Answer 3

Mucosa : absorption of end products
secretes mucus
protection against infectious diseases

Lining epithelium :
Mucus that protects the organ from digesting itself

Helps food along the tract

Lamina propria:
Loose areolar and reticular connective tissue
nourishes the epithelium and absorbs nutrients
Contains Lymph nodes important for defense against bacteria

muscularis mucosae : Smooth muscle cells that produce local movements of mucosa

Question 4

Lamina propria

Answer 4

Loose areolar and reticular connective tissue
nourishes the epithelium and absorbs nutrients
Contains Lymph nodes important for defense against bacteria

Question 5

submuscosa

Answer 5

dense connective tissue containing elastic fibres, blood and lymphatic vessels, lymph nodes and vessels

Question 6

Muscularis externa :

Answer 6

responsible for the segmentation and peristalis

Question 7

serosa

Answer 7

the protective visceral peritoneum

Question 8

esophages has what type of call connective tissue

Answer 8

stratifies squamous epithelium

Question 9

Small Intestine:
The epithelium of the mucosa is made up of:

Answer 9

Absorptive cells and goblet cells
▪ Enteroendocrine cells
▪ Interspersed T cells called intraepithelial
lymphocytes (IELs)
▪ IELs immediately release cytokines upon
encountering Ag

Cells of intestinal crypts secrete intestinal juice
▪ Peyer’s patches are found in the submucosa
▪ Brunner’s glands in the duodenum secrete alkaline
mucus

Question 10

Bile leaves the liver via:

Answer 10

Bile ducts, which fuse into the common hepatic
duct
▪ The common hepatic duct, which fuses with the
cystic duct
▪ These two ducts form the bile duct

Question 11

Chemical Digestion: Carbohydrates

Answer 11

Absorption: via cotransport with Na+, and facilitated
diffusion
▪ Enter the capillary bed in the villi
▪ Transported to the liver via the hepatic portal vein
▪ Enzymes used: salivary amylase, pancreatic
amylase, and brush border enzymes

Question 12

Chemical Digestion: Fats

Answer 12

Absorption: Diffusion into intestinal cells where
they:
▪ Combine with proteins and extrude chylomicrons
▪ Enter lacteals and are transported to systemic
circulation via lymph
▪ Glycerol and short chain fatty acids are:
▪ Absorbed into the capillary blood in villi
▪ Transported via the hepatic portal vein
▪ Enzymes/chemicals used: bile salts and pancreatic
lipase

Question 13

Fatty Acid Absorption

Answer 13

Fatty acids and monoglycerides enter intestinal cells
via diffusion
▪ They are combined with proteins within the cells
▪ Resulting chylomicrons are extruded
▪ They enter lacteals and are transported to the
circulation via lymph

Question 14

Respiratory Membrane

Answer 14

▪ This air-blood barrier is composed of:
▪ Alveolar and capillary walls
▪ Alveolar walls:
▪ Are a single layer of type I epithelial cells
▪ Permit gas exchange by simple diffusion
▪ Secrete angiotensin converting enzyme (ACE),
(has a role in regulation of BP)
▪ Type II cells secrete surfactant (to prevent surface
tension)

Question 15

Alveoli

Answer 15

Surrounded by fine elastic fibers
▪ Contain open pores that:
▪ Connect adjacent alveoli
▪ Allow air pressure throughout the lung to be
equalized
▪ House macrophages that keep alveolar surfaces
sterile

Question 16

Gross Anatomy of the Lung

Answer 16

Lungs occupy all of the thoracic cavity except the
mediastinum
▪ Root – site of vascular and bronchial attachments
▪ Costal surface – anterior, lateral, and posterior
surfaces in contact with the ribs
▪ Apex – narrow superior tip
▪ Base – inferior surface that rests on the diaphragm
▪ Hilus – indentation that contains pulmonary and
systemic blood vessels

Question 17

Pulmonary Ventilation

Answer 17

A mechanical process that depends on volume
changes in the thoracic cavity
▪ Volume changes lead to pressure changes, which
lead to the flow of gases to equalize pressure

Question 18

Nasal mucosa & Nasal Cavity

Answer 18

pseudostratified ciliated colomnar epithelium with goblet cells

Question 19

Kidney Functions

Answer 19

Filter 200 liters of blood daily, allowing toxins,
metabolic wastes, and excess ions to leave the body
in urine
▪ Regulate volume and chemical makeup of the blood
▪ Maintain the proper balance between water and
salts, and acids and bases

Question 20

Cortex –

Medulla –

Answer 20

Cortex – the light colored, superficial region

▪ Medulla – exhibits cone-shaped medullary (renal)
pyramids

Pyramids are made up of parallel bundles of
urine-collecting tubules
▪Renal columns are inward extensions of cortical
tissue that separate the pyramids
▪ The medullary pyramid and its surrounding
capsule constitute a lobe

Question 21

The Nephron

Answer 21

Nephrons are the structural and functional units that
form urine, consisting of:
▪ Glomerulus – a tuft of capillaries associated with a
renal tubule
▪ Glomerular (Bowman’s) capsule – blind, cupshaped end of a renal tubule that completely
surrounds the glomerulus

Question 22

Proximal convoluted tubule (PCT

Answer 22

Reabsorbs water and solutes from filtrate and
secretes substances into it

Question 23

Blood pressure in the glomerulus is high because:

Answer 23

Arterioles are high-resistance vessels
▪ Afferent arterioles have larger diameters than
efferent arterioles
▪ Fluids and solutes are forced out of the blood
throughout the entire length of the glomerulus

Question 24

Urine formation and adjustment of
blood composition involves three
major processes

Answer 24

Glomerular filtration
▪ Tubular reabsorption
▪ Secretion

Question 25

Factors governing filtration rate at the capillary bed are

Answer 25

Total surface area available for filtration
▪ Filtration membrane permeability
▪ Net filtration pressure

Question 26

Chemical Composition of Urine

Answer 26

Urine is 95% water and 5% solutes
▪ Nitrogenous wastes include urea, uric acid, and creatinine
▪ Other normal solutes include:
▪ Sodium, potassium, phosphate, and sulfate ions
▪ Calcium, magnesium, and bicarbonate ions
▪ Abnormally high concentrations of any urinary constituents may
indicate pathology

Question 27

Ureters

Answer 27

Slender tubes that convey urine from the kidneys to the bladder
▪ Ureters enter the base of the bladder through the posterior wall
▪ This closes their distal ends as bladder pressure increases and prevents
backflow of urine into the ureters
▪ Ureters actively propel urine to the bladder via response to smooth
muscle stretch

Question 28

Upon ejaculation the epididymis

Answer 28

Upon ejaculation the epididymis contracts, expelling sperm into the
ductus deferens