Chap 40-42 - Animals Flashcards
4 main types of animal tissue
- Epithelial
- Connective
- Muscle
- Nervous
Epithelial tissue basics
- An apical and a basal side
- Can be squamous (flat sheets of cells) or columnar (cells are vertical)
Connective tissue structure
A few cells scattered through an extracellular matrix of fibres.
Fibres could be embedded in solid or liquid base.
Types of fibres in connective tissue (3)
- Collagenous
- Reticular
- Elastic
Collagenous fibres function
Provide strength while being flexible.
Reticular fibres function
Join connective tissue to adjacent tissues.
Elastic fibres function
Its in the name.
Fibroblasts
Cells in connective tissue that secrete connective fibres.
Structure of bone
Consists of many microscopic units called osteons.
A dense matrix of collagen, mineralised by calcium, phosphate and magnesium.
Adipose cells
Specialised loose connective cells that store a large fat droplet in them.
Three types of muscle tissue
- Skeletal
- Smooth
- Cardiac
epinephrine
adrenaline
Set point (homeostasis)
The value at which a controlled variable is maintained at.
Eg. blood pH of 7.4
Endotherm vs Ectotherm
Ecto - external, environmental temperature
Endo - internal, temperature regulated itself
Poikilotherm vs Homeotherm
Poikilotherm - temperature values a lot with environment
Homeotherm - temperature mostly constant
Endotherms can be poikilothermic (eg. cold during hibernation) and ectotherms can be homeothermic (eg. in the ocean)
Vasodilation
Widening of superficial blood vessels (near body surface) to increase heat loss.
Vasoconstriction
Opposite of vasodilation - decreases heat loss.
Countercurrent exchange
Two fluids moving in opposite directions, maximizing diffusion of heat/molecules.
Countercurrent exchange in blood (thermoregulation)
Veins arranged near arteries.
Heat from nearby arteries diffuse into veins - veinous blood is warm when it reaches the central body & arteries lose less heat to environment when they reach extremities.
Metabolic rate
Total amount of energy an organism uses in a unit of time.
Basal metabolic rate (BMR)
MINIMUM metabolic rate of an endotherm who is:
- not growing
- at rest
- has an empty stomach
- not under stress
- under comfortable temperatures
Standard metabolic rate (SMR)
Metabolic rate of an ectotherm who is:
- not growing
- fasting/not digesting food
- not under stress
- at a comfortable temperature
BMR vs SMR
BMR for endotherms.
SMR for ectotherms.
Aestivation
Hibernation but Summer.
Bolus
A blob of mashed food.
Malnutrition vs Undernourishment
Malnutrition - not enough essential nutrients :C
Undernourishment - not enough calorie :C
Alimentary canal
Digestive track with a mouth on one end and anus on the other.
“Opposite” to just a gastrovascular cavity like starfish.
Peristalsis
Process which moves food along oesophagus/intestines.
Pepsinogen
Inactive form of pepsin that chief cells in stomach secrete.
Sphincter
A ring of muscle that controls the width of a tube - such as the sphincter controlling stomach contents entering the small intestine.
Sections of small intestine
- Duodenum (mainly digestion)
- Jejunum
- Ileum
Transport of nutrients into epithelial cells
Some diffuse through.
Some (amino acids & glucose) are co-transported with sodium ions.
Hepatic portal vein
Blood vessel going from small intestine to liver.
Insulin & Glucagon
Both hormones produced by pancreas.
Insulin - activates glycogen production & glucose uptake.
Glucagon - increases blood glucose by activating glycogen breakdown.
Leptin
Appetite-suppressing hormone produced by adipose (fat) cells.
Open circulatory system
The circulatory fluid (haemolymph) is also the interstitial fluid (around the cells).
Arthropods.
Capillary beds
Networks of capillaries in tissues.
Portal veins
Vessels that carry blood between capillary beds (not towards the heart).
Eg. Hepatic vein
Single vs Double circuit circulation
Single circuit - in fish; blood does one loop from heart to gills to body and back.
Double circuit - in terrestrial vertebrates; blood does a loop between heart and lungs, and then a second loop into the body.
Path of blood in mammals!
- Right atrium/ventricle
- Pulmonary artery, lungs, pulmonary vein
- Left atrium/ventricle
- Aorta, body capillary beds
- Superior or inferior vena cavae
Systole
Phase in cardiac cycle where heart contracts.
Diastole
Phase in cardiac cycle where heart relaxes.
AV valves
Valves between atria and ventricles.
Semilunar valves
Valves between ventricles and arteries.
Sinoatrial (SA) node
‘Pacemaker’ in the heart.
Located in the Right Atrium.
Endothelium
Single layer of squamous epithelial cells that line the inside of blood vessels.
Mechanisms controlling blood flow in capillaries (2)
- Dilation/constriction of arterioles.
- Pre-capillary sphincters.
Pancreas beta cells
Cells that produce insulin.
(Alpha cells are the ones that trigger insulin production)
Composition of mammalian blood
- Plasma (55%) water, ions and proteins
- Cellular elements (45%) erythrocytes, leucocytes and platelets
Atherosclerosis
Accumulated fats in arteries leads to Problems. (stiffening of artery, blockage, inflammation)
Thrombus
A blood clot - formed by platelets and a mesh of fibre.
Partial pressure (gas exchange)
Pressure exerted by a specific gas that is in a mix of gases.
(The amount of pressure the gas contributes to the overall pressure of the mixture)
Gas exchange depends on partial pressure not concentration of the gases.
Surfactant
Surface active agent. A mix of proteins/phospholipids that alveoli produce to prevent them collapsing under surface tension.
Positive pressure breathing
Air is pushed into lungs by making the oral cavity smaller with the mouth/nostrils closed. Used by frogs!
Mammal inhalation/exhalation
Inhale when diaphragm & rib muscles CONTRACT.
Exhale when muscles relax.
Lung’s double-membrane
One membrane around lungs, one in contact with the thoracic cavity. Fluid in-between keeps the two stuck together but allows them to slide past eachother.
Tidal volume
Volume of air inhaled/exhaled each breath.
Vital capacity
Maximum volume of air that can be inhaled/exhaled.
Blood pH in mammal gas exchange
Medulla oblongata and the heart detect when CO2 concentration is too high through pH - CO2 makes it more acidic.
Deeper and faster breathing activated (along with faster heart rate)
Respiratory pigments
Oxygen binding proteins for gas exchange;
- Haemoglobin for vertebrates/some inverts.
- Haemocyanin for blue-blooded critters.
Structure of haemoglobin
4 subunits, each a polypeptide with a haem (a cofactor with an iron atom)
The units display cooperativity.
Myoglobin
Oxygen-storing protein found in muscles, especially in diving animals that need to hold breath for ages.
Bohr shift
Haemoglobin shifts to have less oxygen-carrying capacity in low pH conditions (such as when active tissue release more CO2)
