3ºESO BIOLOGÍA-GEOLOGÍA PROFESOR: PABLOALCARAZ
NOTES UNIT 4: NUTRITION: CIRCULATORY AND
RESPIRATORYSYSTEMSCHAPTER 1 : INTERNAL ENVIRONMENT & BLOOD
INTERNAL ENVIRONMENT
It is the liquid environment that surrounds all body cells and with which they
exchangesubstances: nutrients and waste. Different parts:
1) INTERSTITIAL PLASMA: fluid in between the cells of every tissue. Pass nutrients intocells andreceive their
waste products. This is constantly rennovated by:
2) BLOOD. Carry and pass nutrients + fluid into the interstitial plasma and removes wastesubstances
from it. Nutrients don’t run out for cells and toxic waste molecules don’t accumulate(their
concentration stay constant). Composition and functions:
→ Blood plasma: liquid, 90% water, 10% disolved substances (minerals, all
nutrients,waste products, hormones...). Transport waste.
→ Blood cells: solid. Types:
- Red blood cells (The most abundant. Transport oxygen attachedto
their haemoglobin protein, as well carbon dioxide).
- White blood cells (The least abundant. Defend against infectionand
deasease (destroy phatogens).
- Plateletes (coagulate blood to stop bleeding).
Blood moves through the CIRCULATORY SYSTEM, connecting the other 3 systems
involvedinnutrition: digestive, respiratory and excretory.
CHAPTER 2: CIRCULATORY SYSTEM (BLOOD CIRCULATION) 2.2. BLOOD
VESSELS
Blood flows within these tubes/ducts. (bloodstream = torrente sanguíneo).
Arteries
Capillaries
Take blood out fro
the heart. Reach and connect w
body tissues.
Veins
Take blood back totheheart. a
Thick and elastic muscularwalls. Microscopic vessels. Very thin
walls, (single-celled).
Thin walls with valves(toprevent
fromcoming
back. It only travelsdirection).
Branch into smaller
Small branches calledvenules
Allow molecules tooutside and
vessels:arterioles.
(exchange).
pass
join to formveins.
inone
Each organ has an artery coming and a vein leaving it.
3ºESO BIOLOGÍA-GEOLOGÍA PROFESOR: PABLOALCARAZ
2.2. THE HEART
Pumps blood (=bombear)
Organ with thick wall of muscle tissue
Hollow (=hueco)
Divided in 2 halves not connected (right & left) Each half with 2 chambers:
atrium (upper), ventricle (lower)
Parts and blood vessels: *(write them in an schematic drawing)
Pulmonary veins (4 veins) Left atrium (pl. atria)
Vena cava (2 veins)
Right atrium
Right “atrium→ventricle” valve
Left “atrium→ventricle” valve
Left ventricle
Right ventricle
Right “ventricle→artery” valve (= Semilunar valve)
Left “ventricle→artery” valve (= semilunarvalve)
Pulmonary artery THE HEARTBEAT (= latido Aorta artery
cardiaco)
Continuous movement of the heart pumping
Heart frecuency (= frecuencia card.) = nº heartbeats/minute (average when resting:
70beats/min)Contraction-relaxation phases:
Both right and↓
1st) Atrial systole
2nd) Ventricular systol
3rd) Diastole
left
Atria
contract
relax
“atrium→ventricle”
valves open
close
Ventricles
“ventricle→artery”
contract
valves
Blood move
open
a
ventricles ventricles
(pulmonar &
relax
close
veins (cava &pulmo
arteri
→atria
aorta)
(collect/suckblood)
Blood pressure (=tensión arterial): blood presses with more force the walls of arteries, soas bloodgoes
through them there is a wave of tension on their flexible walls = pulse (=pulso).
2.3. BLOOD CIRCUITS. Circulation is:
1) DOUBLE: to complete the whole round blood passes twice through the heart , each timegoingout and back
through a different circuit: *(draw it in your schema)
General circuit (larger)
Pulmonary circuit (smaller)
Right ventricle → pulmonary art. → arterioles →
left ventricle →aorta art. →arterioles →
→ capillaries (exchage with alveoli air: give CO2 ,
→ capillaries (exchage with all bodyorganstake O2) → venules → pulmonary veins → left tissues-cells: give nutrients &O2, takewaste&
atrium
CO2) → venules →cava v. →right atrium
2) COMPLETE: oxygenated and deoxygenated blood do not mix.
3) CLOSED: blood/cells don’t go out from vessels. Only blood plasma is filtered out to intercellularmatrix.
3ºESO BIOLOGÍA-GEOLOGÍA PROFESOR: PABLOALCARAZ
CHAPTER 3: LYMPHATIC SYSTEM
- It is part of both immune system + circulatory system but with different vessels. - Transports lymph
(=linfa): transparent liquid with lymphatic plasma + lymphocytes (whitebloodcells).
- Not moved by the heart (no pump).
- It is NOT a closed system: thin lymphatic vessels are closed at one end (=ciegos) andhaveonlyone way of
transport: from tissues/intestitial plasma → lymphatic vessels →blood inveins. - It has 2 lymphatic organs
(thymus & spleen = timo y bazo) and lymph nodes (=gánglios linfáticos)all around like in the armpit=axila,
groin=ingles and neck. They produce lymphocytes &cleantheblood.
- FUNTION:
1) Maintain the liquid equilibrium/balance of the internal environment (collect,
cleanandreturn excess plasma from tissues to blood).
2) Helps to defend the body from infection.
CHAPTER 4: EXCRETORY SYSTEM
It is the group of organs that eliminate waste products, produced by cell activity, out fromthebody.
WASTE PRODUCTS (toxic if accumulated):
- Carbon dioxide (from cell respiration with which we obatin energy). - Urea (from
protein destruction)
- Uric acid (from nucleic acid destruction)
- Toxic substances (from alcohol, drugs, medicines...)
ORGANS
1) Respiratory system: Removes CO2 from the blood.
2) Liver: removes (or stores away) some of the extra cholesterol, other toxins substances (fromalcohol,
medicines) and the bilirrubin (from hemoglobin/red blood cells destruction). 3) Sweat glands: Keep the
skin cool and also realease waste substances. 4) URINARY SYSTEM (aparato urinario): excretion through
urine. Organs: kidneys &urinarytract↓
KIDNEYS
We have two. Structure:
- Cortex (corteza): external part.
- Medulla: internal part.
- Pelvis: cavity (funnel) which collects urine from nephrons. - NEPRHONS (nefronas): small tubes that filter
blood to form urine (=liquid with water, mineral salts, urea and uric acid). Over a million per kidney. Located
alongcortexand medulla.
3ºESO BIOLOGÍA-GEOLOGÍA PROFESOR: PABLOALCARAZ
NEPHRON PARTS & URINE FORMATION: *(write them in an schematic drawing) → Capsule:
rounded “tube” + contains a folded capillary (glomérulo).
1st STEP: FILTRATION. Water, mineral salts, other usefull molecules
(vitamins, glucose...) and waste molecules (urea, uric acid) pass from
the capillary blood into the capsule tube.
→ Twisted tubule (túbulo): long twisted tube. In the middle part it has a loop(asa). 2nd STEP:
REABSORPTION. Moving along the tubule muchof the
filtered substances return to blood in the capillaries aroundit: all the
useful molecules and most of the water and mineral salts (not all, to
keep its equilibrium back in the inner environment). But ureaanduric
acid don’t reabsorb.
it continues in the urinary tract, forming 1ml of urine every 125ml of
filtered blood.
Tubules end in collecting ducts: bigger tubes that collect urine frommany nephronsand
channel it into the pelvis. 3rd STEP: COLLECTION.
URINARY TRACT *(draw it in your schema)
- Ureters: two narrow tubes. Connect the two kidneys to the bladder. - Bladder: elastic sac. Accumulates
urine. When full, there is an involuntarily contractionreflex(ofits smooth muscle) that propells urine
towards the urethra. But it can be controlledvoluntarily.
- Urethra: tube that carries urine out of the body. It has an involuntarily sphincter (esfínter, músculo) that only
opens after the previous reflex. Only in men it’s a shared duct with thereproductive system, and it is longer
than in women.