Body Systems Flashcards
What is the gland that releases hormones in response to the messages sent by the control centre?
Pituitary gland
Why is it important to maintain good glucose levels?
So cellular respiration can occur
What is the role of the digestive system?
Break down ingested foods and liquids into substances that the body can absorb and use for tissue repair, energy and growth. Removes waste products (maintaining homeostasis)
What is the first organ of the digestive system?
Mouth
What is the main purpose of the mouth?
Mechanical digestion of food, through mastication and the movement of the tongue. This increase the SA:V ratio of the food. Mastication also combines saliva from the salivary glands with the food, which digests foods
Where are the salivary glands located?
Lining of the mouth
How does the mouth break down the food?
Mastication and movement of the tongue
What does saliva contain?
Salivary amylase, water, mucus
What are the tissues of the mouth?
Lips, hard and soft palate, uvula and tossils, tongue, gums, teeth, cheeks
What is the oesophagus?
A muscular tube that connects the pharynx to the stomach
How does the oesophagus move food forwards?
Peristalsis
How does peristalsis work?
Muscles in the oesophagus wall contract behind the bolus and relax in front of the bolus, in wave-like movements
What is the LES?
Lower oesophageal sphincter
What is the purpose of the LES?
Prevent food from reentering the oesophagus
What is the stomach?
A J-shaped organ that mixes food with enzymes that chemically digest
What happens when food enters the stomach?
The stomach walls begin to contract (mechanical digestion)
What is the first section of the small intestine called?
Duodenum.
What organs empty into the duodenum?
Digestive juices (from the pancreas) and bile (from the gallbladder).
What substances are secreted by the small intestine walls into the duodenum?
Digestive enzymes.
What is further broken down in the small intestine?
Starches, proteins, lipids
What is the second section of the digestive system called?
Jejunum
What happens to food as it travels along the small intestine?
Nutrients get absorbed by villi and microvilli
How is food moved into the jejunum?
Peristalsis
What are the structures that absorb nutrients in the small intestine?
Villi and microvilli.
What are villi?
Small projections that line the small intestine and increase surface area.
What are microvilli?
Even smaller projections that further increase surface area.
What nutrients are absorbed by the ileum?
Vitamin B12 and bile acids.
What are the connections of villi to the circulatory system?
Connected to many capillaries that circulate nutrients around the bloodstream.
What are the components of what is left in the small intestine?
Dead cells, electrolytes, and waste products.
What are the layers of tissue that make up the small intestine?
Mucosa, submucosa, muscularis externa, and serosa.
What has happened by the end of the small intestine?
Nutrients have been absorbed
What does the pancreas do?
Produce pancreatic juices
What is the liver’s function in relation to digestion?
Produceand secrete bile (digestive enzyme)
What is the gallbladder’s purpose?
Store bile until needed
What is the function of the large intestine?
Absorb excess water, mineral salts and vitamins
What does the large intestine produce?
Stool
What is the purpose of the rectum?
Store faeces until appropriate time to expel
What is the purpose of the anus?
Allow faeces to be expelled
What is the purpose of the herbivore’s digestive system?
Break down food so nutrients can be absorbed
What do most herbivores rely heavily on for nutrients?
Cellulose
What do herbivores use instead of enzymes to break down cellulose?
Bacteria that can break it down
What is an extra organ that some herbivores?
Caecum
What is an example of an animal with a caecum?
Wombat
What occurs in the caecum?
Bacteria ferment the cellulose
What do some animals with a caecum do?
Re-ingest their poo to get more nutrients
What is an example of an animal that re-ingests their poo?
Possums
What do some fibrous-eating herbivores do?
Using ruminatory digestion
How does ruminatory digestion work?
The animal has a four chambered stomach. the first two stomachs mechanically digest before regurgitating the cud, chewing it again and then using the next two stomachs to chemcially digest
What is an adaptation to the length of the small intestine in herbivores?
Some have very long small intestines, to allow more nutrients to be absorbed
What is the role of the excretory system?
Maintain osmotic balance, remove metabolic waste/byproducts
What happens in the kidney?
Filtration, selective reabsorption, urine production
What is the kidney mainly made up of?
Nephrons
What the kidney do?
Filter blood and remove waste products to be made into urine
What are the ureters?
Tube-like structures that transport urine from the kidney to the bladder
How does urine travel through the ureters?
Peristalsis
What is the purpose of the urinary bladder?
Store and expel urine
What is the urethra?
Tube that urine leaves the body through
What is the goal of the nephron?
Process waste products to create urine
What is the first part of the nephron?
The glomerulus
What is the glomerulus?
Specialised mass of capillaries
What is the glomerulus surrounded by?
Bowman’s Capsule
What happens to blood in Bowman’s Capsule?
Blood pressure squeezes out much of the fluid within the glomerulus
Where does the blood go after the glomerulus?
Travels through proximal convoluted tubule (highly important products are reabsorbed here)
Where does the blood go after proximal convoluted tubule?
The descending arm of the Loop of Henle. Some water is reabsorbed here
Where does the blood go after the descending arm of the Loop of Henle?
the ascending arm of the Loop of Henle
What is redabsorbed out of the ascending arm of the Loop of Henle?
Ions
Where does the blood go after the Loop of Henle?
the distal convoluted tubule. then the collecting duct (water leaves here)
What is the name for what is left after nephron filtration?
Urine: water, urine, excess salts
What does the endocrine system do?
Use glands to produce hormones that tell certain organs to carry out/change functions
What are some things that the endocrine system regulates?
Metabolism, urine production, blood sugar
What are the hormones that the hypothalamus produces?
ADH, oxytocin
What are the hormones the pituitary gland makes?
Antidiuretic hormone: helps nephrons control amount of water reabsorbed
Oxytocin: stimulates contraction of uterus and mammary glands
Human growth hormone (HGH): stimulates growth, especially of the bones and muscles
Gonadotropins (LH and FSH): regulate testes and ovaries
Thyroid stimulating hormone (TSH): stimulates thyroid
Adrenocorticotropic hormone (ACTH): stimulate the release of cortisol
Prolactin: causes breasts to grow and make breast milk
What is the role of the pineal gland?
Produce melatonin, regulating sleep
What is the role of the parathyroid glands?
Make parathyroid hormone, which increases blood calcium levels. Regulates other vitamins
What hormone controls the thyroid gland?
Thyroid-stimulating hormone (TSH)
What does the thyroid gland regulate?
Metabolism (through thyroxine), reducing calcium (calcitonin)
What is the purpose of the thymus gland?
Produce a hormone called thymosin, which stimulates T lymphocytes (white blood cells)
What do the adrenal glands do?
Make cortisol (response to stress, increased metabolism, decreased immune system), corticosteroids, aldosterone and sex hormones.
Make adrenaline and noadrenaline
What system are the ovaries a part of?
Female reproductive system
What is the purpose of the ovaries?
Function of secreting oestrogen (promotes the development and maintenance of female characteristics) and progesterone (stimulates growth of the lining of the uterus).
What is the purpose of the testes?
Make testosterone: promotes the development of male reproductive tissue and secondary sexual characteristics.
Where is TSH released from?
Anterior pituitary gland
What is the function of TSH?
Stimulate the thyroid to release thyroxine. Thyroxine is essential for regulating how fast metabolism occurs, and has the secondary functions including managing the heart, muscles, digestion, bone health, and brain development.
