Organ Systems Flashcards
What is an organ?
collection of tissues with a common function
What is an organ system?
group of organs with a common set of functions
What are the 10 main organ systems?
intergumentry, musculoskeletal, nervous, endocrine, urinary, reproductive, cardiovascular, lymphatic, respiratory, digestive
What is the intergumentry system?
the skin
What do the dermis and epidermis rest on?
hypodermis and subcutis
What type of cells is the epidermis made up of?
stratified squamous epithelium which is keratinised to various extents
What percentage of body fat does the hypodermis store?
50%
What are the functions of the intergumentry system?
protection, sensation, temperature regulation, vitamin D production, excretion
What layer of the skin is avascular and aneural?
epidermis
What is skin colour determined by?
melanin, blood flow and stratum corneum thickness (layer of keratin)
What is melanin?
a skin pigment
What is melanin produced by?
melanocytes
what do melanosomes contain?
melanin
What does melanin give protection from?
UV
What are the 2 layers of the dermis?
papillary and retiucular
What does the dermis contain?
connective tissue, blood vessels, nerve endings, hair follicles, smooth muscles, glands, lymphatic vessels
What is found in the connective tissue in the dermis?
fibroblasts (collagen, elastic and reticular fibres), few andipocytes and macrophages
What are the blood vessels in the dermis used for?
nutrient and waste exchange for the dermis and live epidermis
Give an example of smooth muscles found in the dermis
erector pili cases the hair to stand up on skin
What layer of the dermis are fingerprints produced by?
papilary layer
What is the function of fingerprints?
increase friction and improve grip
What is dermal bone?
bone that grows within the dermis
What is the process of dermal bone growth called?
intra membranous ossification
How does dermal bone grow?
accretion only
What does accretion mean?
gradual accumulation of layers
What is the outer layer of dermal bone deposited by?
osteoblasts
What is the musculoskeletal system made up of?
skeletal muscles and the skeleton
What is the skeleton made up of?
bones, tendons and ligaments
What important function of life does the skeleton allow?
movement
What are the two parts of the skeleton?
axial and appendicular
What bones make up the axial skeleton?
skull, mandible, spinal column, ribs, sternum
What bones make up the appendicular skeleton?
limbs (thoracic and pelvic), scapula, clavicle
What part of the appendicular skeleton is not found in some quadrupeds?
clavicle
What does the marrow in long bones produce?
blood cells
What is a joint?
a place where 2 or more bones come together
What do joints make possible?
movement
What are the 3 main types of joint?
fibrous, cartilaginous, synovial
How are the articulating surfaces of 2 bones joined in a fibrous joint?
joined with fibrous tissue
Is there a joint cavity in fibrous joints?
no
How much movement is there between fibrous joints?
little to none
What are the 3 types of fibrous joint?
sutures, syndesmoses, gomphoses
Where may you find sutures joints?
top of the skull
What are syndesmoses joints joined by?
ligaments
give an example of a syndesmoses joint
radius and ulna
What are gomphoses joints?
one bone is fixed into a socket formed in another
give and example of a gomphoses joint
teeth
What are cartilaginous joints joined by?
cartilage
What sort of cartilage are primary cartilaginous joints made of?
hyline
Where would you find primary cartilaginous joints?
growth plates, ribs and sternum
What sort of cartilage are secondary cartilaginous joints made of?
fibrocartilage
Where would you find secondary cartilaginous joints?
within the pelvis
Where are synovial joints found?
in limbs and between vertebra
What is the joint contained in in a synovial joint?
synovial capsule
What is the function of synovial fluid?
lubricates the joint
What are the ends of bones covered by in a synovial joint?
hyline cartilage
What do ligaments do?
prevent movement of joint in some directions
What are ligaments made of?
dense regular collegenous connective tissue
how do muscles attach to bone?
via tendons
What can a muscle be attached to?
bone, cartilage or skin
Where is the origin of a muscle fixed to?
the least mobile bone or area
Where is the insertion of a muscle located?
in the more mobile bone or area
What are the 2 main types of muscles?
agonist and antagonist
What does an antagonist muscle do?
performs the opposite movement to the agonist muscle
How are muscles grouped?
according to function
What does the nervous system control?
movement, physiological processes and intellectual functions
What sort of system is the nervous system?
regulatory
What are the 2 elements of the nervous system?
central and peripheral
What makes up the central nervous system?
brain, cerebellum, spinal chord
What does the relative size of a structure in the brain reflect?
the importance of that area for a species
Where does the spinal chord exit the cranium?
foramen magnum
What does the spinal cord run through?
vertebral canal
What is white matter?
mylinated fibres
What is grey matter?
non-mylinated neuron bodies
Where do spinal nerves carrying sensory and motor fibres exit the vertebral canal?
intravertebral formina
What are nerve cells called?
neurones
What is the role of neurones?
transmit electrical stimuli through the body
what are the 3 main components of a neurone?
body, dendrites and axon
What do neuralgia do?
support nourish and insulate neurones
What is the function of ependymal cells?
produce CSF and move it around with cilia
What is the function of microglia?
phagocytic cells which clear nerve cells
What do astrocytes form?
form the blood/brain barrier
What is the function of schwann cells?
produce mylin for axon insulation, within the PNS
What is the function of oligodendrocytes?
form mylin sheaths around many cells, within the spinal cord
What sort of system is the endocrine system?
regulatory
What does the endocrine system produce?
hormones
name glands in the body which secrete hormones?
pituitary, pineal, thyroid, thymus, adrenal, pancreas, overies/testes
What is the role of the pituitary gland?
regulates all other glands
What is the role of the pineal gland?
regulates circadian rhythms
What is the role of the thyroid?
regulates metabolism and homeostasis
What is the role of the thymus?
an immune organ, it produces T Lymphocytes
Name the 9 functions of the endocrine system
metabolism, ion regulation, immune system regulation, control of blood glucose/nutrient levels, tissue maturation, water balance, heart rate and blood pressure regulation, control of reproductive functions, uterine contractions and milk release
Where is the pituitary gland located?
near the brainstem
What regulates the pituitary gland?
hypothalamus
What does the pineal gland affect?
reproductive function
What function regulates the effect of the pineal gland in some species?
photoperiod, affected by light e.g. in horses where their season only occurs in spring/summer
What are the two lobes of the thyroid connected by in humans?
isthmus
What does the thyroid affect?
metabolic rate
What trace element is found in thyroid hormone?
iodine
What can a deficiency in iodine cause?
hypertrophy of thyroid gland
Where is the thyroid located?
in the throat
Where are the adrenal glands located?
on the kidneys
What does the cortex of the adrenal gland release?
corticosteriods, mineral corticoids, androgens
What does the medulla of the adrenal glands release?
adrenaline and noradrenaline
What hormones do the ovaries produce?
oestrogen and progesterone
What hormones do the testes produce?
testosterone
What does the reproductive system influence?
behavior
What does the reproductive system include?
gonads and products (hormones and gametes) and tubes to transport gametes
What is the female reproductive system made up of?
ovaries, uterus, vagina
What is the uterus the site of?
fertilisation and foetal development
What is the male reproductive system made up of?
testes, ducts, accessory glands, penis
What is an example of an accessory gland in the make reproductive system?
prostate
What do differences between species of the female reproductive systems depend on?
the number of offspring the mother is able to have at one time
How does the uterus of humans, horses, cattle and sheep compare?
large uterus as single offspring is most likely
What part of the uterus of quadrupeds is not present in humans?
uterine horns
Why are uterine horns large in species that have litters/multiple offspring?
the foetuses develop here
How many functional ovaries do reptiles and birds have?
1
What may be different about male reproductive organs between different species?
orientation of testes (horizontal or vertical), penis (some become engorged with blood and others unfold/straighten)
What is the urinary system the main system for in the body?
excretion
Why are kidneys so vital?
some products of body processes (e.g. protein catabolism produces ammonia) are toxic and could kill if not safely removed
What do kidneys do?
pressure filter blood to produce urine, process blood plasma, remove waste products from blood, regulate blood pH, water and ion balance.
What do the ureters basically do?
transport urine to the bladder
What does the bladder do?
stores urine until it can be released
What does the urethra do?
transports urine out of the body ( and forms part of the male reproductive tract)
Where are the kidneys located?
in the lumbar region
What is the hilum?
area of all organs where blood vessels and nerves move in and out
What makes up the outer layer of the kidney?
fibrous capsule
What is found in the cortex of the kidney?
renal corpuscles and convoluted tubules
What is found in the medulla of the kidneys?
renal tubules
What shapes are formed in the medulla?
pyramids
What structure does urine collect in?
calyces
Where does urine drain into once it is in calyces?
pelvis of the kidney
from the pelvis of the kidney where does the urine go?
out of the hilum through the ureter
What is the name of the smooth muscle that surrounds the bladder?
detrusor
Where does the detrusor muscle thicken in the bladder and why?
around the urethra to act as internal urethral sphincter
What makes the bladder distensable?
rugae stretch to allow the bladder to increase in size, transitional epithelium lines bladder
What is the name of the transitional epithelium found within the bladder?
uroepithelium
Where else in the urinary system does transitional epithelium line?
ureters and urethra
What type of muscle are the ureters and urethra made of?
smooth
What makes up the cardiovascular system?
heart, blood vessels and blood
What is the function of the cardio vascular system?
transports substances through the body, involved in immune response and temperature regulation
What substances does the cardiovascular system transport through the body?
gasses (exchanged at lungs), nutrients, waste products (filtered by kidneys), hormones
How is the cardiovascular system involved in an immune response?
transports cells and chemicals to site
How is the cardiovascular system involved in temperature regulation?
vasodilation or constriction
Where is the heart located?
in the thoracic cavity close to the lungs
What sort of pump is the heart?
double
What is the left sided pump involved with?
systemic circulation
What is the right sided pump involved with?
pulmonary circulation
How many chambers are there in the heart?
4
What are the names of the 4 chambers?
left atrium, right atrium, left ventricle, right ventricle
What are the chambers of the heart regulated by?
valves
What are differences in the heart between species?
size, shape, orientation, coronary circulation, branching of aorta
What is the main artery in the body?
aorta
Where does the aorta originate?
exit of left ventricle
Which arteries supply the head, thoracic limbs and thoracic structures?
brachiocephallic trunk and subclavian arteries
Which arteries supply abdominal structures?
coeliac and mesenteric arteries
Which arteries supply the pelvic structures and pelvic limbs?
common iliacs
Which vein takes blood from the superior/cranial body to the right atrium?
superior vena cava
Which vein takes blood from the inferior/caudal body to the right atrium?
inferior vena cava
Which vein delivers blood from the digestive tract to the liver?
hepatic portal vein
What system is the lymphatic system closely related to?
cardiovascular
What is the lymphatic system made up of?
lymph, lymphatic vessels, lymphatic tissues, lymph nodes, tonsils, spleen, thymus
What is lymph?
clear fluid that runs in lymph vessels
What are the 3 functions of the lymphatic system?
fluid balance, fat absorption, defence
How does the lymphatic system assist with fluid balance?
removes fluid from tissues, that has not been directly returned to blood vessels.
Why is fluid balance important?
reduces oedema and tissue damage
Where is fat absorbed from into the lymphatic system?
the digestive tract
What are the specialised cells of the lymphatic system which absorb fat in the small intestine?
lacteals
How do lymph nodes act to defend the body?
filter microorganisms and act locally if they are encountered
What organs produce lymphocytes?
spleen and thymus (only in the young)
What is the other role of the spleen in horses and dogs?
stores blood
In which body cavity is the respiratory system located?
thoracic cavity
What separates the thoracic cavity from the abdominal cavity?
diaphragm
What is the main muscle of respiration?
diaphragm
What does the respiratory system include?
lungs and respiratory passages
Name the 5 respiratory passages
nasal cavity, larynx, pharynx, bronci, trachea
Which parts of the respiratory system form the upper and lower respiratory tract?
upper: nasal cavity, pharynx, larynx
lower: trachea, lungs, bronchi
What are the functions of the respiratory system?
oxygen and carbohydrate exchange between blood and air. Regulation of blood pH
What happens to air in the nasal cavity?
inspired air is warmed and humidified
What does increased humidity in inspired air do?
helps with smell
What happens at the pharynx?
oral and nasal cavities meet
What is the larynx used for?
pronation and protection of trachea by the epiglottis
What 2 species cannot breathe through their mouths due to the epiglottis permanently covering the trachea at the back of the mouth?
horses and rabbits
What is the trachea held open by?
incomplete cartilage rings
What type of cartilage is found in the trachea?
hyline
What are lungs the organ of?
respiration
What is exchanged within the lungs?
gas (oxygen and carbon dioxide)
Via what blood vessel do lungs receive de oxygenated blood?
pulmonary arteries
What is the texture of the lungs in mammals?
spongy due to alvioli
What 2 main parts make up the digestive system?
digestive tract and accessory organs
What is the digestive tract?
muscular tube of smooth muscle that goes from mouth to anus
What parts of the body make up the digestive tract?
mouth, pharynx, oesophegus, stomach, small and large intestines, rectum and anus
What are the parts of the small intestine?
duodenum, jejunum and illium
What are the parts of the large intestine?
caecum, ascending colon, transverse colon, descending colon
What are the accessory organs?
salivary glands, liver, pancreas
What does the liver do?
produces bile which digests fats and processes products of digestion and blood
What does the pancreas do?
secretes digestive enzymes directly into duodenum
What are the 6 ways that food is processed during digestion?
ingestion, mastication, propulsion, mixing/secretion, digestion/absorption, elimination
What happens during ingestion?
intake of solid/liquid through oral cavity
What is mastication?
chewing of food to reduce it’s size and expose it to salivary enzymes which will start digestion
What is propulsion?
movement of food usually by peristalsis
What is the purpose of mixing and secretion during digestion?
food is mixed with digestive enzymes and further broken down
What happens during the digestion/absorption phase of digestion?
breakdown of large organic molecules into component parts that can then be absorbed
What happens during elimination?
waste products from digestion are removed from the body via faeces
What do species digestive systems reflect?
where they live and what they eat
What sort of fermenters are cows and sheep?
foregut
What do foregut fermenters have in their stomach that enables them to break down cellulose?
bacteria that ferment cellulose
What is the relationship between fermenters and the bacteria they use known as?
symbiotic relationship
Why do cows and sheep have an expanded stomach?
to accommodate the bacteria
What sort of fermenters are horses?
midgut
Where are the fermenting bacteria located in midgut fermenters?
caecum and part of the colon
