Tissue, Organs, and Organ Systems

function of circulatory system

transport blood around body/carry oxygen + nutrients to body cells+carry waste products away from cells

function of respiratory system

allow breathing

thorax

top part of body seperated from abdomen by diaphragm

bronchus

major air passages that diverge from trachea

bronchide

minor branches in which bronchus divides

lungs

gas exchange organ in mammals

trachea

airway leads from larynx to bronchi

alveoli

tiny air sacs where gas exchange occurs

pleural membranes

thin layer of tissue that covers lungs and lines interior walls of chest cavity, allows lungs to freely move inside ribcage

intercostal muscles

muscles that combine to fill space between ribs

ribcage

skeletal structure that forms thorax

diaphragm

muscular partition that seperates thorax from bdomen, contracts to increase volume of thorax and inflate lungs

How are alveoli adapted for diffusion?

• have large surface area to volume ratio

• have a thin membrane

How goes gas exhange work in the alveoli?

• oxygen leaves alveoli and enter blood stream

• carbon dioxide leave through alveoli and out

Oxygen moves from an area of high concentration to low concentration. This is called..

diffusion

breathing rate

number of breaths/time to take the breaths

heart rate

number of beats/time to take the beats

Humans have a

• double circulatory system

  • blood passes through heart twice during one system

left/right atrium

chamber of heart into which blood enters from pulmonary vein or vena cava

left/right ventricle

chamber in heart which pumps blood out of heart through pulmonary artery or aorta

valves

structure within heart or vein which prevents blood from flowing in wrong direction

aorta

artery that transports blood from heart to rest of body

pulmonary artery

blood vessel which transports blood out of heart to lungs

pulmonary vein

blood vessel which transports blood into heart from lungs

coronary arteries

arteries that branch off aorta and surround heart

vena cava

blood vessel which transports blood into heart from the rest of body (not lungs)

Name all the steps of blood flow through the heart.

1. Blood flows into the two atria from the vena cava and the pulmonary vein.

2. The atria contract, pushing blood into ventricles.

3. The ventricles contract, forcing blood into pulmonary artery and aorta.

4. Blood flows to organs through arteries, then arteries through veins.

What is the resting heart rate controlled by?

cells in right atrium wall that acts as a pacemaker

What do cells produce that spread to surrounding muscle cells causing them to contract?

small electric impulses

Function of arteries

carry blood away from heart

Function of capillaries

where blood passes substances back and forth from cells

Function of veins

carry blood towards the heart

Adaptations of arteries

• walls are strong + elastic

• contain thick layers of muscle

  • make them strong + elastic fibres to allow them to stretch and spring

• thick walls compared to size of lumen

Adaptations of capillaries

• permeable walls so substances can diffuse

• walls are one cell thick

  • increases rate of diffusion

• narrow

  • large SA:V ratio

    • increases rate of diffusion

Adaptations of veins

• lower pressure

  • walls do not need to be as thick

• bigger lumen than arteries to help blood flow

• valves to direct blood in right direction

function of arteries

carry blood away from heart

function of veins

carry blood towards heart

function of capillaries

where blood passes substances back and forth from cells

function of valves

to assist blood in correct direction

The blood in the valves are at a…

low pressure

Arteries do not have valves because…

the pressure from the heart is strong enough to ensure the correct direction of blood flow

blood

type of tissue that’s function is to transport substances around the body

function of red blood cell, its special features and why they’re important

• to transport oxygen around the body

• biconcave shape to give large S.A

• contains red pigment called haemoglobin that carries oxygen

• has no nucleus to make more room for oxygen

function of white blood cells, its special features and why they’re important

• to defend against microorganisms that cause disease

• produces antibodies which releases antitoxins to fight microorganisms

• engulfs unwelcome microorganisms through phagocytosis

function of platelets, its special features and why they’re important

• to help the blood clot at the wound

• can connect to eachother

• lack of platelets means excessive bleeding

• stops microorganisms

function of plasma, its special features and why they’re important

• to carry all substances in blood

• pale, straw-coloured

What substances can plasma carry?

• red + white blood cells, platelets

• nutrients

• carbon dioxide from organs to lungs

• urea from liver to kidneys

• hormones

• proteins

• antibodies + antitoxins produced by white blood cells