Organisation in animals

Question 1

What is a tissue

Answer 1

Group of similar cell that work together to carry out a particular function. It can include more than one type of cell

Question 2

What is an organ

Answer 2

A group of different tissues that work together to perform a certain function.

Question 3

Give 3 types of tissues in mammals

Answer 3

• Muscular tissue: contracts to move whatever it’s attached to e.g. moves stomach walls to churn food
• Glandular tissue: makes and secretes chemicals like enzymes and hormones e.g. makes digestive juices to digest food
• Epithelial tissue: covers some parts of the body e.g. inside of the gut, and outside and inside of the stomach

Question 4

How does gas exchange happen in the alveoli?

Answer 4

• alveoli surrounded by blood capillaries. This is where gas exchange happens
• blood passing next to the alveoli has returned to the lungs from the rest of the body by the pulmonary artery
• blood coming from body contains lots of carbon dioxide and very little oxygen
• oxygen diffuses out of the alveolus (higher concentration area) to the blood (lower concentration)
  -carbon dioxide diffuse out of the blood(high concentration) into the **alveolus **(low concentration) to be breathed out

Question 5

What 3 components make up the circulatory system?

Answer 5

• Heart: heart muscle contracts to generate force to move the blood
• Blood vessels: tubular structures that carries blood through all organs and tissues of the body
• Blood: the transport medium that carries nutrients and chemical Messenger molecules(hormones) to the tissues and removes waste products for them

Question 6

What is a double circulatory system?

Answer 6

The blood passes through the heart twice per complete circuit around the body.

Question 7

What are the 2 routes in a double circulatory system?

Answer 7

• Pulmonary circuit: deoxygenated blood passes from the left ventricle to the lungs and then returns as oxygenated blood to the left atrium
• Systemic circuit: oxygenated blood passes for the left ventricle to the rest f the body and then returns as deoxygenated blood to the right atrium

Question 8

Where are the lungs?

Answer 8

Thorax

Question 9

What is the order in which air travels to the lungs after being inhaled?

Answer 9

trachea, bronchus, bronchiole, alveolus

Question 10

A blood cell enters the heart through the Vena Cava. Make a flow chart of its journey from there, ending at the aorta. Name the valves in your answer.

Answer 10

vena cava, right atrium, through tricuspid valve, right ventricle, semi-lunar valve, pulmonary artery, lungs, pulmonary vein, left atrium, through bicuspid valve, left ventricle, semi-lunar valve, aorta

Question 11

What is the heart made of?

Answer 11

• Cardiac muscle tissue
• Nervous tissue

Question 12

Around the heart, arteries called _____ arteries branch off the _____ and surround the __________ muscle tissue.

Answer 12

coronary, aorta, cardiovascular

Question 13

What does the pacemaker do?

Answer 13

Controls the natural rate of the heartbeat

Question 14

Where is the pacemaker located?

Answer 14

The electrical impulses are generated in specialised patch of cells that are located on the right atrium wall

Question 15

What can be used if a patient has an irregular heartbeat?

Answer 15

an artificial pacemaker

Question 16

What do artificial pacemakers do?

Answer 16

Artificial pacemakers are electrical devices used to correct irregularities in the heart rate by sending electrical impulses to the heart muscle

Question 17

Name the three types of blood vessels.

Answer 17

arteries, veins, capillaries

Question 18

Blood in the arteries is under high pressure, so they need valves. True or False?

Answer 18

False

Question 19

Veins have valves. True or False?

Answer 19

True

Question 20

Why do veins need valves?

Answer 20

blood in the veins flows at low pressure and often against gravity, so valves are needed to prevent backflow and pooling

Question 21

Describe and explain the layers of a vein.

Answer 21

• Thin walls with elastic fibres and muscle: blood pressure is low so valves are present to prevent back flow and pooling of blood
• Wide lumen: reduce resistance between the blood and the walls of the vein
• Irregular lumen

Question 22

Describe the layers and their functions of the artery wall (including the lumen).

Answer 22

• Walls are made of elastic fibres and smooth muscle
• Thick walls: to withstand high pressure
• Elastic tissue: allows walls to stretch when blood is forced through and recoil when pressure drops
• Narrow lumen- maintain high blood pressure
• Regular and round lumen

Question 23

Name 4 ways in which capillaries are adapted to their functions.

Answer 23

• Walls are 1 cell thick
  -Permeable walls: substance can diffuse in and out
• Lumen same size as red blood cell
• Pores(gaps between cells making up the capillary wall): allow substances to move through

Question 24

Function of artery?

Answer 24

• carries oxygenated blood at a high pressure away from the heart

Question 25

Function of vein?

Answer 25

- carries **deoxygenated blood** at a low pressure towards from the heart

Question 26

Function of capillaries?

Answer 26

- **exchange nutrients** e.g. glucose and oxygen from plasma to cells - **exchange of waste products** e.g. carbon dioxide from cells to plasma.

Question 27

rate of blood flow =

Answer 27

Volume of blood / number of minutes

Question 28

How are red blood cells adapted to their function?

Answer 28

- **Biconcave shape**: gives larger surface area - **No nucleus**: allows more room to carry oxygen - **Contains haemoglobin**: binds to oxygen to become **oxyhaemoglobin** to transport oxygen to lungs and tissue

Question 29

What is the function of a white blood cell?

Answer 29

Defend the body against microorganisms that cause infection

Question 30

How can white blood cells perform their function?

Answer 30

- **engulf foreign microorganisms** through process of **phagocytosis** and digest them - **produce antibodies**: proteins that bind to foreign antigens and destroy them - **produce antitoxins**: to neutralise any toxin produced by foreign microorganisms

Question 31

Description of plasma

Answer 31

Yellow translucent liquid

Question 32

What is the function of plasma?

Answer 32

- carries: - **red and white blood cells, platelets** - **glucose, amino acids** : these are soluble products of digestion which are absorbed from the gut and taken to the cells of the body - **carbon dioxide**: from organs to the lungs - **urea**: from liver to kidneys - **hormones, proteins** - **antibodies and antitoxins** produced ny white blood cells

Question 33

What is the description and structure of platelets?

Answer 33

- tiny fragments of cells - no nucleus

Question 34

Function of platelets?

Answer 34

- **help blood to clot** (clump together) at a wound- this seals the wound and stops you from loosing too much blood - **stops microorganisms entering the wound** - **lack of platelets** can cause excessive **bleeding and bruising**

Question 35

what are blood products

Answer 35

components of blood prepared from donated blood - blood tranfusion centres

Question 36

Advantages of using blood component thearpy:

Answer 36

- **more patients can be treated** - the **dose** of required component can be **optimised** - more **cost effective** + **effcient**

Question 37

what is the use of the blood product : Packed red blood cells

Answer 37

- used to **restore oxygen carrying capacity** - paitients with **anaemia / blood loss**

Question 38

what is the use of the blood product : fresh frozen plasma

Answer 38

treatments for patients with **excessive bleeding**

Question 39

what is the use of the blood product : Platelets

Answer 39

**treatment / prevention** of **bleeding** in **low platelet count** patients

Question 40

what is a stent

Answer 40

metal mesh that insets into the artery to keep lumen open

Question 41

describe how a stent is inserted into an artery

Answer 41

- **catheter** used to insert **inflated balloon** to open up artery - **stent** inserted and **balloon deflated** - **catheter + balloon removed**

Question 42

why would someone have a stent fitted

Answer 42

when **artery narrows** due to **fatty deposits** in the artery wall

Question 43

Advantages of stents:

Answer 43

- **lowers risk of heart attack** with people with CHD - **operation is quick, effective** - patients recover quickly

Question 44

Disadvantages of stents:

Answer 44

- **compilcations** can occur during surgery - **risk of infection** - **risk of forming blood clot** - can lead to stroke / heart attack

Question 45

what are statins used for

Answer 45

to **reduce blood cholesterol levels** which **slow down rate of fatty material deposit**

Question 46

How do statins work: (LDL + HDL)

Answer 46

- **reducing** amount of **LDL** cholesterol on blood - LDLs **carry fat to artery wall** + **increase** amount of **fat deposited** - **Increasing** amount of **HDL** - HDL **carry fat away** from **artery wall + decrease** amount of **fat deposited**

Question 47

Advantages of statins:

Answer 47

- reduces risk of strokes, CHD, heart attacks - may prevent other diseases

Question 48

Disadvantges of statins:

Answer 48

- must be **taken regularly** over **long period of time** - **Negative side effects** - headaches, kidney failure - **not immediate effect** - takes time for beneficial effect

Question 49

causes of faulty heart valves:

Answer 49

- heart attack - infection - old age

Question 50

function of heart valves

Answer 50

**maintain** the **blood flow in one direction**

Question 51

consequences of faulty valves:

Answer 51

- breathless - low oxygen supply - death - chest pain

Question 52

what 2 types of valves can faulty valves be replaces with

Answer 52

- biological valves - mechanical valves

Question 53

advantages of mechanical valves:

Answer 53

- **last** a **long time** - very **effective** - **permanent** - no need for replacement - **no ethical issues**

Question 54

advantages of biological valves:

Answer 54

- **no medication needed** - fully **effective**

Question 55

Disadvantages of mechanical valves

Answer 55

- **anticoagulants** for life (increase risk of blood clotting) - **Open heart surgery** needed - **unsuitable for children** - cant be still growing

Question 56

Disadvantages of biological valves

Answer 56

- need **replacing** after **~15 yrs**

Question 57

why have scientists developed artifical heart

Answer 57

- **shortage of donor hearts** - **extend patients life**