Organisation of Cells Into Tissue and Organs Flashcards
3 major salivary glands and locations? Other glands?
Parotid (under ear and cheekbone)
Submandibular (posterior top of neck)
Sublingual (below mouth)
Many smaller glands scattered in oral mucosa
What type of cells does the parotid gland have?
Serous secreting cells (stain intensely)
What type of cells does the submandibular gland have?
Mucous secreting cells
Striated ducts in relation to salivary glands? What does this do?
In most glands with ducts, they only convey the product but striated ducts MODIFY saliva passing though, by pumping salt out of fluid so saliva is HYPOTONIC to blood (saliva does not taste salty)
What are basal striations?
Infoldings of cell membrane accompanied by lines of mitochondria to power molecular pumps in membrance
4 layers of the digestive tract?
Mucosa
Submucosa
Muscularis externa
Serosa/adventitia (if the layer attaches to surrounding tissue, it is adventitia, but otherwise, it is serosa)
Structure of the mucosa?
3 parts:
Epithelium - sits on BASAL LAMINA
Lamina propria - loose connective tissue
Muscularis mucosae - thin layer of smooth muscle
What is the submucosa?
Loose connective tissue
What is the muscularis externa?
2 thick layers of smooth muscle (inner circular layer and outer longitudinal layer)
What is the serosa?
Outer layer of connective tissue that either suspends the digestive tract or attaches to other organs
Different types of mucosa?
Protective - non-keratinised, stratified, squamous epithelium, as in oral cavity, pharynx, oesophagus, anal canal
Absorptive - columnar epithelium with villi and tubular glands, as in small intestine
Secretory - columnar epithelium with extensive tubular glands, as in the stomach
Protective and absorptive - columnar epithelium with tubular glands, as in the large intestine
What is the digestive tract’s own nervous system? How does it work?
Enteric Nervous System (ENS) - receives input from autonomic nervous system but coordinates gut mobility locally.
Neurones are arranged as groups -called ganglia - between the 2 muscle layers of muscularis externa
What are the layers of the trachea?
Respiratory epithelium
Lamina propria (loose connective tissue)
Submucosae (contain seromucous glands)
Hyaline cartilage of tracheal ring
How is mucous produced in trachea?
Goblet cell in respiratory epithelium produce mucous together with submucosal glands.
Difference between bronci and bronchioles?
Bronchi are large diameter airways and have hyaline cartilage in walls
Bronchioles have no cartilage in walls; have smooth muscle (allow contraction)
How do epithelial cells of respiratory tree vary?
Epithelial columnar cells tend to get shorter further down tree
Lining of alveoli?
Simple squamous epithelium
Structure of liver?
Consist of lobules - have similar hexagonal arrangement
At each corner, branch of hepatic portal vein and hepatic artery (deliver blood to lobule)
Blood passes sheets of liver cells,called hepatocytes, when passing from corner to centre lobule
In centre is central vein which drains to hepatic vein
What is the portal triad?
Branch of hepatic portal vein + bile duct + hepatic arteriole
Functions of exocrine pancreas?
Produce approx 1 litre of digesetive juices per day, containing proteases (to breakdown proteins), lipases (to breakdown lipids), nucleases (to breakdown DNA/RNA, etc)
These enter duodenum (1st part of small intestine) via pancreatic duct
Structure and function of endocrine pancreas?
Consists of small, scattered island of tissues (Islets of Langerhans) which produce a number of hormones, including insulin
Similar in appearance to parotid gland
Structure of kidney?
Renal corpuscle - tuft of capillaries, surrounded by epithelium, where production of urine begins
Complex tubule system - many components (liquid/dissolved) of blood pass into here and are then selectively reabsorbed
Renal corpuscle + tubule units = NEPHRONS
Structure of the blood?
45% cells and 55% plasma
99% of cell are rbcs (erythrocytes) - lack a nucleus
1% are wbcs (leukocytes); 5 principal types:
Eosinophils
Neutrophils
Basophils
….are collectively termed granulocytes
Monocytes
Lymphocytes
Structure of muscular arteries?
3 layers:
Tunica intima - extends to an internal elastic membrane
…and separated by the external elastic membrane are the
Tunica media
Tunica adventitia
Structure of arterioles?
Only 1 or 2 layers of smooth muscle in tunica media and almost no adventitia
Structure of capillaries?
Composed of endothelial cells and a basal lamina
Structure of veins?
Thin muscular walls - lower BP than arteries
What is the lymph vascular system?
System of relatively thin-walled vessels that drain excess tissue fluid into bloodstream
Lymph transported to lymph nodes for immunological surveillance
Lymphatic system structure and method for flow production?
System has no central pump but no smooth muscle in walls and this, together with hydrostatic pressure in tissue and compression of vessels by voluntary muscle, combines with valves in vessels, produce FLOW.
