Human Bio systems

Veins

carry blood towards the heart

Vena cava -

carries blood from upper and lower body towards right atrium

Pulmonary vein -

carry blood from lungs twoards left atrium

Arteries -

carry blood away from heart

Aorta -

carries blood from LV to cells of body

Pulmonary artery -

carries deoxygenated blood from the right ventricle towards lungs (left and right)

A valve's function is to

prevent the backflow of blood between chambers (Tricuspid and Mitral) or from arteries into the chambers (Pulmonary and aortic)

what r the semilunar valves

• pulmonary

• aortic

what r the atrioventricular valves?

• tricupsid

• mitral(bicupsid)

vein structure

• thin thickness of walls

• valves present

• large lumen size

elastic walls function

expansion and conraction w changes in blood pressure

muscular walls function

allows vasoconstriction and vasodilation to control blood flow

thickness of walls function

resist bursting under high pressure

valves function

prevent backflow

lumen suize function

if narrow it helps maintain high blood pressure in arterys

pulmonary circulation

takes deoxygenated blood from the right ventricle to the lungs and returns oxygenated blood to the left atriym. the right ventricle is the pump

systematic circulation

takes oxygenated blood from left ventricle to all tissues in body and returns deoxygenated blood to rate atrium. left ventricle is pump

functions of blood

• transport

• regulation

• protection

plasma function

• transport co2

• transporting nutrients and wastes

erythrocytes (red blood cells) fucntion

1. transporting co2

2. and oxygen

structural features of erythrocytes (rbc)

• biocooncave disc

• no nuceus

• edges are thiciker for more harmoglobin space

platelets (thrombocytes)

• responsible fir clotting of blood

• prevent blood and entry of pathogens

the following will occur in small tears in capilleries

1. damage to blood vessels cause platelts to stick to site of injury

2. forms a plug of platelets

3. platelets secerete substances causing vasoconstriction to reduce blood flow

following will occur in larger injurys if first steps are insufficent

4. clotting factors will b released to form a meshwork of fibrin

5. fibrin mesh will trap blood cells platelets and plasm to form a clot

6. over time this mesh will contract and cause a scab

lymphatic system

has an important role in immunity as well as returning fluid to the circulatory system

3 structures of lymphatic sytem

• lymphatic vessels

• lymph nodes

• lymph

lymph consists of

• white blood cell

• water

• proteins

• fats

Lymph nodes fucntion

• foreign poarticles and disease causing organisms get trapped and destroyed by cells in lymph nodes

structure of lymph vessels

• blind ended

• larger than capilleries

• permeable

• thin kayer of smoth muscle

structure of lymph vessels

• fluid leaks out of cappilleries

• allow proteins and larger organism to pass

• passes through lymph node which aids in immunity

• excess fluid is retuned via lymph vessls, to large veins in chest

systole

heart contracts

pumps blood out

diastole

when heart relaxes and refills w blood

cardiac output ml/minute

stroke volume (mL) x heart rate (beats/minute)

antigen

molecule on surface of cell that immune system can recognise

antibody

protein that recognises and binds to antigens

oral and nasal cavity function

• air cleaned warmed and moistened

• nasal secretions can destroy some bacteria w anti-bacterial enzyme called luysozyme

funciton of mucus

• trap dirt molecules before they enter the lungs

nasal lining cavity

muscous lining

• contains goblet cells which sectrete a clear sticky mucus

bronchal tree

• consist of larynx trachea bronchus and bronchioles

• c shapes cartilliagewhich prevent airways closing under pressure

• lined w cilated mucous membrane

• mucus traps dirt and microbes

• the cillia sweep dirty mucus up trachea nad into throat

Alveoli

respiration

is the transport od oxygen to tissues

• and transport of co2 in oppsite direction

internal respiration

exchange of o2 and co2 between blood and tissues

external respiration

movement of o2 and co2 between the lungs and the blood stream

inhalation

• the diaphram contracts flattens and moves down

• the external intercostal muscles contract

• ribcage move up and out

• thoraric volume increases

• throraric pressure decreases

• movement of air into lungs

exhalation

• the diaphram relaxes and moves up

• the external intercostal muscles relax

• ribcage move down and in

• thoraric volume decreases

• throraric pressure increases

• movement of air out of lungs

structure of alveoli

• thin walls

• large num of alveoli w large surface area

• surface alveoli are moist

• continous supply of blood thrpugh cappilaries

• continous inhalation and exhalation

how do thin walls aid exchange

• less distance for gases to diffuse through

• increases rate of diffusion

large number of alveoli with large surface area

• more surface for gas to diffuse

• increases rate of diffusion

surface of alveoli are moist - how does it aid

• allows gasses to dissolve

• increase rat eof diffusion

have continous supply of blood through capilleries function aid in echange

• maintain high concentration gradients

• increase rate of diffusion

continous inhalation and exhalation - how does it aid?

• maintains high concentration gradients

• increase rate of diffusion

6 basic functions of the digestive system

1.Ingestion of food and water

2.Mechanical digestion of food

3.Chemical digestion of food

4.Movement of food along the alimentary canal

5.Absorption of digested food and water into the blood and lymph

6.Elimination of material that is not absorbed

MECHANICAL DIGESTION

physical breakdown of food particles

3 examples of mechanical digestion

1. mouth : teeth

2. stomach: churning

3. gall bladder: bile which emulsify fat into smaller droplets

food particles are smaller meaning

increased surface area

Chemical digestion

use enzymes to break down large complex molecules into smaller simpler molecules

3 examples of chemical digestion

1. salivary amalyse

2. stomach (protein into polypeptides

3. stomach acids

proteases which turn

protein into polypeptides in stomach

bile salts

emulsify lipids in liver

amalyse

starch into maltose

pancreas

lipase

triglecerides into fatty acidss

pancreas

endopeptidase

peptides into amino acids

pancreas

Bicarbonate ions in liver

neutralise stomach acid

The mouth - mechanical

• chewing (mastication) teeth break down food to increase surface area

• swallowing - tongue shapes food into bolus

The mouth - chemical

• salivary amylase

3 types of teeth

1. insisors

2. canines

3. premolars and molars

oesophigus

• connects pharynx —> stomach

peristalsis

• wave like contractions

• Contains a double layer of muscle that is able to constrict and push the bolus into the stomach.

Stomach mechanical

• churning - mixes food w gastric juice

• due to extra oblique layer of muscle the stomach is able to churn and mix food w gastric juice to create chyme

stomach chemical

• Hcl - ativates a substance called pepsinogen to form pepsin

• pepsin - digests proteins into polypeptides

the movement is of chyme depends on

pyloric sphincter

ling of stomach secretes

gastric juice

gastric juice contains

hcl, mucus and digestive enzymes

duodenum functioin (1)

chemical digestion

jejunum ⁽²⁾

• absorption of carbs and proteins

ileum (3)

• absorption of vitamins, biles salts and other remaining nutrients

small intestine mechanical

• peristalsis which helps break up the bolus and mix it with juices and bile

chemical digestion small intestine

• pancreatic juice secreted into the small inetstine contains many enzymes

• intestinal juice secreted by small intestine contains many enzymes

bile

produced in the liver

stored in galll blader and secreted into the duodenum

is emulsification mechanical. orchemical

mechanical

bile function

• emulsify fat

• breaks it into smaller droplets and increases surface area by lipases

intestinal juice

maltase, sucrase and lactase - break down disaccharides (maltose, sucrose and lactose) into monosaccharides (galactose, glucose and fructose)

intestinal lipase - breaks down lipids into fatty acids and glycerol

Peptidase - Breaks down peptides into amino acids

large intestinal surface area is using - into blood stream

• long small intestine

• villi

• microvilli

• mucosal fold

structure of a villus

•The structure of a villus is ideally suited to its function of nutrient absorption. Each villus;

•Is approx. 1 mm long

•Has Single layer of cells

•Contains a lacteal (a lymph capillary) surrounded by blood capillaries

small intestine - asorption

• blood capilleries

• lacteals

faces contains

• water

• undigested food

• bacteria

• bile pigments

• remaining of cells

elimination

• semi solid material left inthe colon after absorption of water pushes into the walls of the rectum by peristalsis

• as walls stretch they trigger defecation

• anal sphincter relaxes and faces can b passed

excretion

rmoval of wastes of metabolism

• removes wastes before they reach a harmful concentration inthe body

parts involved in excretion

•Lungs – excrete carbon dioxide from cellular respiration

•Liver – processing chemicals into safer forms

•Sweat glands – excrete salts, urea, lactic acid

•Alimentary canal – excrete bile pigments

•Kidneys – excrete nitrogenous wastes

skin sweat contains

sodium chloride, lactic acid, urea, some drugs.

liver (excretory organ)

•Processes chemicals into a safer form that can be excreted
(e.g. deamination)

•Detoxifies alcohol and many other drugs

•Deactivates hormones for excretion by the kidneys

•Breaks down haemoglobin from dead red blood cells to produce bile pigments, which are then eliminated

Deamination (liver)

removes amino acid group (NH2) from amino acid molecule in liver by enzyme deaminase

formula for deamination

amino acid + oxygen —(deaminase) —> ammonia +carbohydrate

formula of ammonia (NH3)

ammonia +co2 +energy —> urea +water

kidney works to

• rid body of wastes (urea, uric acid and creatine

• maintain constant concentration of materials in body fluids

• regulate balance of fluid salt and PH

kidney

filters blood and produce urine

renal capsule

tough fibrous layer surrounding the kidney

renal artery

transports blood into kidney

renal vein

transports blood away from kidney

cortex

outer part of kidneys