Excretion + Circulation

Two main needs of organisms -- excretory system and

1. Osmoregulation -- maintain H2O balance
2. Removal of toxic substances -- dilute these with H2O

Catabolic reactions

Breaks down; hydrolytic reaction

Anabolic reaction

To build, so synthesize; dehydration synthesis

Egestion

Undigested waste, feces

Excretion

Removal of metabolic waste, cell waste

Metabolic wastes

Waste created through metabolism of cells

Main metabolic waste

* CO2: cell respiration -- catabolic, breaking down of glucose
* H2O: cell respiration or any dehydration synthesis reaction
* Salt: neutralization reactions, acid + base
* Nitrogenous wastes: protein metabolis

Protein metabolism

Break down protein/amino acids and produces nitrogenous wastes

Deamination (liver)

Breaks apart amino acids → ammonia

NH3: ammonia

* Very toxic
* Must be diluted
* To dilute -- 1NH3: 1,000,000 H20
* then need to excrete out of the organism
* Marine organisms

Urea

* Land organisms
* Ammonia → (convert) → urea
* Uses a lot of ATP
* to dilute - 1 Urea: 100,000 H2O

Uric acid

* Not soluble in H2O
* No/minimal H2O lost
* Large ATP cost
* Reptile, birds, insects, desert creatures (not camels)
* Comes out as a white paste

Four main excretory organs

* Kidney
* urine → urea, water, salt
* Liver
* salt \[bile\]
* Skin 
* sweat (water/salt), urea
* Lungs 
* CO2, water

What does the skin do?

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* Protects our body
* Physical
* Pathogens (disease-causing organisms)
* Chemical protection
* Radiation (melanin absorption/ UV)
* Thermoregulation – maintains body temperature
* Waterproof
* Sensations
* Vitamin D production
* Stores energy

Liver performs many functions, including the production of urea:

1. Deamination → secretion of NH3

NH3 → Urea


2. Creates bile

How many kidneys do you need?

You can survive with one but it is better to have two

Functions of the kidney

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* Filter Blood – MAIN FUNCTION
* Once the unclean blood enters, the kidneys filter it, and out comes urine and clean blood
* Regulates blood pressure
* Through water retention (holds onto water)
* Red blood cell production (control of rbc production – don’t actually make them)
* Monitors blood cell count
* Erythropoietin (EPO) – a hormone that the kidney sends to the blood marrow to tell it to make more RBC
* High altitude results in less oxygen in the air so your body needs to make more which makes more EPO and makes more RBC
* Regulates pH

What could kidney stones be due to?

Diet or genetics

Dialisis

external kidney, a machine does the filtering of blood for you and the clean blood goes back in

How much urine does your kidney produce a day and what does the color of your urine say about your drinking habits?

It makes about 1L of urine per day. If your urine isn’t clear, your a probably dehydrated.

Bladder

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* Fills up
* Has stress receptors on it telling you that you have to go to the bathroom
* Not good to keep stretching out your bladder and letting it get full because it will lose its elasticity
* Sphincter at the bottom prevents bladder from bursting

Bacterial infections (bladder)

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* Bacterial goes up the urethra
* UTI: bacterial infection of the urinary tract
* If left untreated it could cause kidney failure

Nephron

Functional unit of kidney that cleans blood and makes urine

Three processes nephron uses to clean blood and create urine/filtrate

* Filtration
* Reabsorption
* Secretion

Filtration

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* Happens between blood ball of capillaries (called glomerulus) and bowman's capsule
* Works because of blood pressure
* Passive transport – no energy used here
* Non-selective – don’t differentiate good vs bad
* Sort by size
* All the small stuff goes in the Bowman’s capsule (Urea, H2O K+, Amino acids, creatine, salt, glucose)
* Glucose, amino acids, and H2O shouldn’t be thrown out and the body will have to take them back
* Big chunky stuff like RBC and WBC remains in the blood vessels/capillaries

Reabsorption

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* Specific – use specific protein channel (passive)/pumps (active)
* Passive and active depending on what you are going to use
* Tubule → blood
* Take back the good stuff that got filtered and pull it out of the filtrate
* Substances reabsorbed
* H2O – osmosis – passive
* Glucose – active (w/ pumps)
* Salt – X factor (can do anything) – passive/active
* Body moves it around in order to move the water, changes tonicity
* Amino acids – active

Secretion

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* Throw out more bad stuff (toxins/drugs)
* Blood → tubule
* Selective and active

Filtrate

Stuff in the nephron tubule, stuff that is supposed to be garbage

Nephron tonicity

Blood is hyper and Bowman’s capsule is hypo so that water flows into the blood vessels

Cortex (region of kidney)

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* Top part
* Less salty
* Distal tubule
* Everything that’s left that’s good comes out, only waste should remain

Medulla (region of the kidney)

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* Bottom part
* Salty
* Loop of Henle
* Collecting duct

Loop of Henle

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* Descending
* Only permeable to water, eventually reaches equilibrium
* Ascending 
* Salt removal (active) to make the inside hypo
* Not permeable to water

Collecting duct

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* Has extra channels in it that only open when ADH (antidiuretic – stops you from peeing) opens them so that water can come out
* When ADH goes down, you pee more
* When it goes up, you retain the water
* Caffeine and alcohol blocks ADH causing you to pee more

ADH hormone (antiduretic)

* controls the rate of water excretion
* released for posterior pituitary gland
* acts when the body is in a state of under-hydration and needs to retain water
* causes more water to be reabsorbed by collecting ducts

Vena Cava

Veins that bring blood to the right atria/heart

Atria

Receive blood from the body

Left atrium

Pumps blood to the whole body

Right Atrium

Pumps blood to the lungs

Pulmonary artery

Brings blood to the lungs, only deoxygenated artery

Pulmonary vein

Only oxygenated vein in the body

Aorta

Largest blood vessel, under the most pressure

Which side of the heart is deoxygenated and which is oxygenated?

Right side -- deoxygenated

Left side -- oxygenated

Autorhythmic

Can generate its own electrical impulse and can contract on its own. The heart is autorhythmic.

Needs of organisms/cells

* Get O2, H2O, glucose, nutrients
* Removed CO2, nitrogenous (waste)

How do single celled organisms get nutrients and get rid of wastes?

Through diffusion and active transport. It can do this stuff since it is in contact with the environment.

Multicellular organisms use ___________ to get nutrients and remove wastes.

circulatory system

Parts of the circulatory system

* Pump -- “heart”
* Tubes -- “blood vessels“
* road ways
* Liquid - holds “stuff“ -- “blood“

Arteries and Arterioles

* carry blood away from the heart
* Oxygenated
* high pressure

Veins and venules

* carry blood to the heart
* Deoxygenated blood
* Low pressure

Capillaries

* next to every cell
* One cell thick
* Exchange of substances between the blood and the interstitial fluid occurs in several ways
* Non-polar molecules (O2 and CO2) diffuse through the epithelial cells of the capillary wall
* Larger molecules may be carried across an epithelial cell in vesicles formed by endocytosis on one side of the cell and release their contents by exocytosis on the other side
* Water and small solutes (sugars and salts) can move freely through the pores in the wall and narrow clefts between the epithelial cells making up the wall -- the capillary wall is leaky

Blood pressure

how much force the blood is exerting on the walls of the arteries

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Normal: 20/80

Systolic 20 means the heart is contracting/expanding

Diastolic 80 means the heart is relaxing

Why do veins and arteries dilate?

Because they have smooth muscles

What can smooth muscle do?

Moves around blood and has the ability to dilate as well as constrict

What do blood vessels on the skin’s surface do?

They dilate to remove heat from body into the environment

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Drinking alcohol increases this.

What do your veins do when it’s cold out?

They constrict to maintain body temperature

What is the only blood vessel where exchange with cells occur?

Capillary

Which blood vessel is on the surface and which is deeper? Why?

Veins are on the surface and arteries are deeper so that they are better protected.

Which has less smooth muscle, the veins or the arteries?

The veins

What does the valve do?

It prevents backflow

What is the result of the extremely low pressure in the veins?

It makes it hard to move blood valves however the wideness of the veins helps with that.

Why is the capillary under pressure? And why do you want this?

It is under pressure because it is narrow and you want it narrow so things move slower allowing diffusion to occur.

What does interstitial fluid do?

It acts as a buffer for the cells and allows us to maintain homeostasis

What does the constant movement of the blood vessels allow?

It allows for the maintaining of the concentration gradient by allowing diffusion to occur.

What are varicose veins?

When the valve malfunctions so the vein twists on itself and goes to the surface of the skin.

What is always placed next to a vein?

Contractile-type things like muscles are next to veins so the moving muscles can squeeze the veins to allow blood to move.

What does aspirin do?

It dilates and thins blood

Angioplasty

Inflate balloon to press plaque up against edge of blood vessel to create space

What is a heart murmur? What does it mean? How could you cure it?

It is a faulty valve in the heart.

It means that there is sometimes backflow.

Up until a human reaches a certain age, it can fix itself. After that, you will need a valve replacement.

Thoracic Cavity

Area of the heart, lungs, ribcage, diaphragm

Pericardium

Membrane surrounding the heart

* fluid that lubricates heart results in less friction during heat beats

SA (sinoatrial) node

* Group of cells that act as the “pacemaker“
* Can be influenced by the brain

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* the pacemaker which sets the rate at which all the muscle cells of your heart contract
* Located on the upper wall of your right atrium
* It generates electrical impulses
* Sequence of electrical events in the heart
* Signals from the SA node spread through both atrium so they contract in unison
* Impulses pass to a relay point called the AV node (located between the RA and RV) which delay the signal about 0.1 second before the ventricles contract
* Specialized muscle fibers relay the signals to the apex of the heart and up through the walls of the ventricles triggering the strong contractions that drive blood out of the heart

What’s a normal bpm?

40-60 bpm

Heart attack

Cells die in heart due to a lack of O2 -- a blockage prevents the cells from getting O2 which kills them

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* damage or death of cardiac muscle tissue usually as a result of blockage of blood vessels
* Electrical shocks applied to the chest by a defibrillator may reset the SA node and restore proper cardiac function
* AED (automatic external defibrillators): designed to be used by laypeople and are placed in public places where they are easily accessible

Bypass surgery

Take blood vessel (vein) from another part of the body to replace the one in the area of the heart attack to increase blood flow in that area.

AV (atrioventricular) node

Tells ventricles to contract

ECG (electrocardiogram)

Shows the electrical impulse in the heart

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* Provides data about heart health such as the existence of arrhythmias
* Arrhythmias: abnormal heart rhythms including heart rates that are too slow or fast and fibrillations (flutterings) of the atria or ventricles
* Fibrillations may occur in a healthy heart when drugs such as caffeine cause a group of cells to generate heart beats outside the SA node

Tacchycardia

Heart beat is too fast (180 bpm)

Bradycardia

Heart beat is too low

What does an artificial pacemaker do?

It helps take over for a non-functional SA node

How much blood is there in human?

About 5L

What is the purpose of blood?

* Transports O2
* Immunity/ protection
* Temperature
* Thermoregulation

Red blood cells (erythrocytes)

* Carry O2
* Disc shape
* Contain hemoglobin which combines O2 and is iron derivative
* Anemia → low RBC/hemoglobin count
* hectorite
* Fatigue, internal bleeding
* 2-3 million RBC/sec
* 1 uL - 4 million RBC
* lives 120 days
* no nucleus or organelles
* made in the bone marrow
* Liver and spleen process out old ones

Polycethemia

* too many RBC
* caused by a tumor

Sickle-cell

* turn moon shaped and become rigid
* blocks blood vessels
* resistant to malaria

White blood cells (Leukocytes)

* 80-90 years
* Have all organelles, can leave circulatory system
* Different types of WBC
* Basophil
* Eosinophil
* Neutrophil
* Lymphocyte
* Monocyte
* Defense and immpunity

Platelets

* cell fragments
* responsible for blood clotting

Why is the shape of the red blood cells important?

It increases the surface area thereby increasing the amount of diffusion that can occur

Systemic circulation

Heart→whole body→heart

Pulmonary circulation

heart→lungs→heart

Renal circulation

Heart→kidney→heart

Coronary circulation

Heart→heart→heart

hepatic circulation

Heart→liver→heart

Order of circulatory system

Arteries→arterioles→capillaries→venules→veins→vena cava→heart

Open circulatory system

called “open” because fluid is pumped through open-ended vessels and flows out among the tissues; there is no distinction between the circulatory fluid and the interstitial fluid

Closed circulatory system

* the vessels keeping blood distinct from the interstitial fluid
* Three kinds of vessels:
* Arteries
* Carry blood away from the heart to body organs and tissues
* Capillaries
* Convey blood between arteries and veins within each tissue
* Veins
* return blood to the heart
* Often called the cardiovascular system

Human cardiovascular system

* Blood leaves the heart through the **pulmonary arteries** that carry deoxygenated blood to the lungs and the **aorta,** which begins the oxygenated blood’s journey to the body tissues
* Blood flows into the heart through **pulmonary veins** which bring oxygenated blood from the lungs and two large veins that carry blood from the body tissues
* The **superior vena** cava returns deoxygenated blood to the heart from the upper body and the **inferior vena cava** brings it from the lower body

Atrioventricular (AV) valve

valves between the atria and ventricles

Semilunar valve

Located at the exit from each ventricle

Cardiac Cycle

* the rhythmic sequence in which the heart contracts and relaxes
* When the heart contracts: it pumps blood
* when the heart relaxes: blood fills it’s chambers

Diastole (cardiac cycle phase) -- relaxed

blood flows into all four chambers; blood enters the RA and from the vena cava and the LA from the pulmonary artery, the AV valves are open and the semilunar valves are closed; lasts about 0.4 second and the ventricles nearly fill with blood