Functioning Systems Flashcards
What are Meristematic tissues?
Are made of cells that can undergo cell division and can continue to divide for the life of the plant.
* Found in the tips of roots and shoots
What are Permanent tissues?
Are made of cells that can no longer divide.
- Dermal tissue
- Ground tissue
- Parenchyma tissue
- Collenchyma tissue
- Sclerenchyma tissue
- Vascular tissue
- Xylem tissue
- Phloem tissue
Tissues involved in intake of water?
Absorption and uptake of liquid water through root hairs.
* Root hairs are extensions of cells of the epidermal tissue that forms the outer cellular covering of the root
* Water enters the root hairs from the soil solution by osmosis > water moves across the cells of the cortex to the xylem > transported as a fluid to all cells.
Xylem tissue:
- is the transport of water and dissolved minerals taken up by root hair cells to
the rest of the plant. - Consist of
o Tracheids
o Vessels
o Fibres
o Parenchyma
What is Transpiration?
Water travels up the plant and evaporates out of the leaves. - leaf stomata open
Stomata?
- Leaves contain pores (stomata)(singular: stoma).
- Each is surrounded by two guard cells.
- They open and close depending on whether the guard
cell is Turgid or Flaccid.
Turgid Stoma?
o If the guard cell has a high water content they are turgid
o The pore is open
Flaccid Stomata?
o The guard cells lose water
o The stoma close
Tissues in Animals?
Tissues are formed by groups of cells of similar type —
or even a single type — that act in a coordinated manner
to perform a common function.
Types of Tissues in mammals?
- Epithelial tissues: sheets of cells that cover external and internal surfaces.
- Muscle tissues: contract and enable movement.
- Connective tissues: provide structural support.
- Nervous tissues: are made of different kinds of nerve cells
(neurons).
Organs in Animals?
An organ is a group of different kinds of tissue grouped
together to form a discrete structure that works
cooperatively to perform a specific function.
Systems in Animals?
A system is composed of a group of organs that
cooperate to carry out a single life-sustaining
function, such as excretion or digestion
Organs of the Digestive System?
Mouth
Salivary Glands
Oesophagus
Stomach
Liver
Pancreas
Gall Bladder
Small/Large Intestines
Rectum/Anus
Alimentary canal (gastro-intestinal tract)?
Muscular tube, approximately 8m long,
* Includes the mouth, oesophagus, stomach, duodenum, small intestine, and large intestine (colon and rectum).
Peristalsis?
The muscular contractions of the wall of the gut move food along the tract.
Mechanical digestion:
Breaking down food into smaller pieces. Chewing and churning
Chemical digestion:
Enzymes
Tissues in the Digestive System?
Epithelial tissue > mucosa (the innermost lining of the digestive system)
* Connective tissue > sub-mucosa (connective tissue forming the second layer of the gut lining muscularis muscle tissue of the gut)
* Muscle tissue > muscularis.
* Connective tissue > serosa (outer connective tissue which encloses the gut)
Epithelial Tissue: Functions
- Protection
- Absorption
- Secretion
Connective Tissue: Functions
Forms the second layer of the gut wall, the sub-mucosa,
where it occurs as areolar connective tissue with blood
vessels, lymphatics and nerves; it also forms the outermost
layer, the serosa.
* Is also present in the solid organs of the digestive system.
* In the hollow organs of the alimentary canal provides
structural support to other tissues.
Muscle Tissue: Functions
Is important in the structure and function of the digestive
system
* Muscles have the ability to contract (and relax)
Sphincters?
- Thickened rings of muscle which control the opening and closing of a tube
- When relaxed and open, the sphincter allows food to pass and, when contract and closed, prevents the forward movement of food.
The Mouth
Saliva contains the enzyme amylase, which acts on the
starch molecules and begins to break them down into shorter chains such as dextrins and disaccharides.
When a person decides to swallow the food in the mouth. A
rounded mass of food, a bolus, is forced to the back of the
mouth at the start of swallowing. Once the swallowing process has begun, it then becomes automatic.
The Oesophagus
- The oesophagus is a soft, muscular tube, about 20 to 23
centimetres long in an adult. - The oesophagus secretes mucus and transports food
from the mouth to the stomach. - Peristalsis is the contraction of muscles in the walls
which moves the food from the mouth to the stomach.
The Stomach
- Gastric juice is a mixture of mucus, enzymes,
hydrochloric acid and water. - Chyme is the food, saliva and gastric juice.
- The gastric juices contain hydrochloric acid and pepsinogen,
which is the inactive form of the enzyme pepsin.
The Large Intestine
- The large intestine is about 1.5 metres long and consists of two
main parts, the colon and the rectum. - Bacteria in the colon digest about 30–40 per cent of the fibre into
fatty acids and also produce small amounts of some vitamins,
particularly vitamin - Water moves freely, in either direction, across the membranes of the
intestine at any point along its length. - The contents of the rectum are called faeces.
- Faeces leave the gut by the anus.
Digestion in Herbivores
- Hind-gut fermenters have modified regions of the colon and caecum for bacterial digestion.
- Foregut fermenters have an enlarged stomach or part of the oesophagus to accommodate bacterial digestion.
- Ruminants have one stomach and many compartments.
Enzymes
- Are biological catalyst.
- Are made of proteins.
- Lowers the activation energy
- Has a specific active site shape that is complimentary to the substrate.
- Denaturing: when the enzyme’s structure is changed so that they can no longer function as enzymes.
- Inactive: When the conditions are optimal the enzyme will begin to work.
Endocrine System
Is composed of a network of endocrine glands and it functions as a chemical messenger system.
* Hormones: chemical messengers, released by endocrine
glands, that regulate the function of distant organs, each with a specific receptor for its hormone
* Protein hormones are hydrophilic and so cannot diffuse
easily across the plasma membrane > complementary
receptors are on the plasma membrane.
* Steroid hormones are hydrophobic and so can easily
diffuse across the plasma membrane > complementary
receptors are in the cytosol/nucleus.
Pituitary Gland
- Is located at the base of the brain immediately below the hypothalamus
- Is composed of two major lobes:
o Anterior pituitary: anterior lobe of the pituitary gland; it is made of glandular tissue that synthesises and secretes several releasing hormones that activate other endocrine glands.
o Posterior pituitary: posterior lobe of the pituitary gland; it is made of neural tissue that stores and releases hormones sent from the hypothalamus.
Adrenal Gland
Small endocrine glands located on top of the kidneys
that produce various hormones
* Corticoid hormones: are steroid hormones, including
aldosterone and cortisol, produced by cells of the cortex
of adrenal glands
* Cortisol: a steroid hormone produced by the adrenal
cortex that has many roles, including control of blood
glucose levels during stress and the body’s recovery
from the stress response
* Adrenaline: Fight or flight hormone
Thyroid gland
An endocrine gland located in throat that produces and
secretes the hormones including T3 and T4
Parathyroid glands
- Are endocrine glands located on the rear surface of the
thyroid gland. - The parathyroid glands are surrounded by a thin fibrous
capsule and have networks of capillary vessels
throughout their tissue.
Excretion:
The process of removal from the body of
various types of waste material arising from its metabolic
activities.
Urinary tract:
A series of hollow organs comprising ureters, bladder and urethra that transport urine to the outside of the body
Tissues in the Excretory System
- Epithelial Tissue
o Linings of the hollow organs are formed by transitional
epithelium
o Linings of the tubules are composed of simple epithelial tissue > the nephron. - Connective Tissue
- Muscle Tissue
Kidney
- The basic functions performed by the nephrons are:
o Filtration
o Reabsorption
o Secretion
o Excretion. - It is through these processes that the kidneys:
o Remove metabolic wastes from the blood
o Conserve salts and water: maintained within narrow limits - osmoregulatory function.
Hollow Organs
- Ureter: transport of the urine made in the kidney to the
bladder. - Urinary Bladder: is a sac-like structure that serves as a
temporary storage for urine. - Urethra: is a tube that allows urine to pass outside the body
Excretory System in Invertebrates
- Ammonia (NH3) is the initial N-waste
- Ammonia can be converted into urea (NH2CONH2) or
uric acid (C5H4N4O3) but these conversions require an
investment of energy
What is Negative Feedback?
When the response feeds back to and counteracts the
change in the variable. This is a homeostatic mechanism.
What is Positive Feedback?
When a change in a variable produces a response that
further amplifies the stimulus and increases its effect.
Thermoregulation
The regulation of body temperature
What is Piloerection?
Hair standing on end
Hypothermia?
Condition in which an individual has an extremely low body
temperature and is at risk of death
Acute hypothermia?
Occurs when a person is suddenly exposed to extreme cold
Exhaustion hypothermia?
Occurs when a person is exposed to a cold
environment and cannot generate sufficient metabolic heat to maintain their core body temperature due to exhaustion or lack of food
Hyperthermia?
Condition in which core body temperature exceeds the
upper end of the normal range without any change in the temperature set point
Heat exhaustion?
An increase in core body temperature; symptoms include poor coordination, slower pulse and excessive sweating; may develop into heat stroke
Heat stroke?
A critical and life- threatening condition where brain function is affected; symptoms include high core body temperature in excess of 40 °C, slurred speech, hallucinations and multiple organ damage
Osmoregulation
Process by which the volume of body fluids and their
solutes concentrations are controlled
Antidiuretic hormone:
Hormone produced by neuro-secretory cells in the hypothalamus; increases reabsorption of water into the blood from distal tubules and collecting ducts of nephrons in the kidney
Type 1 Diabetes
*When the blood glucose level is higher than normal
Hyperglycaemia
*Insulin production is defective
Type 2 Diabetes
*Build up of glucose in the blood
*Insulin is present, but the cells are said to be
insulin resistant.
Symptoms of Diabetes include:
*Thirst
*Frequent urination
*Fatigue
*Blurred vision
*Hunger
Treatment of Diabetes
*Type 1: Insulin injections
*Type 2: Lifestyle changes
Hypoglycaemia
*Is a condition in which there is too little glucose in the blood.
*The most common time hypoglycaemia occurs is during diabetes treatment.
*May lead to fainting or even coma.
*Signs of hypoglycaemia include:
– Excessive hunger
– Trembling
– sweating
– nausea.
Hyperthyroidism
*Excessive production of thyroid hormones drives up the basal metabolic rate, affecting many functions.
*Symptoms
– An increase in the resting heart rate
– An elevated body temperature
– An increase in appetite
– Unexplained weight loss
– Sensitivity to and sweating in warm conditions
– Relative insensitivity to cold conditions.
*Management of hyperthyroidism may involve surgical removal of part of the thyroid gland or the administration of anti-thyroid medication that interferes with the ability of the thyroid gland to take up iodine from the blood.
Hyperglycaemia
A condition where glucose levels in the blood rise above normal
Symptoms -
- Dry Mouth
- Thirst
- Weakness
- Headache
- Blurred Vision
- Frequent Urination
