human bio semester 1 exam Flashcards

Question

Explain the kidneys in the excretory system

Answer 1

Primary excretion organs Each kidney is about 11cm long Surrounded by fibrous connective tissue called the capsule Three layers: Cortex: outer layer Medulla: middle layer Renal pelvis: inner layer

Answer 2

• Nephron: functional unit of the kidney, its where urine is formed • Kidneys are composes of a large number of nephrons • About 2 million nephrons in each kidney

Answer 3

Each nephron consist of a renal corpuscle and a renal tube, located in renal pyramids Renal corpuscle: - Consists of the glomerulus and glomerular capsule: expanded side of the nephron Renal tube: - Leads away from the glomerular capsule - About 5 cm long - Begins with a winding section called the proximal convoluted tubule - Beyond this each tubule has a straight portion before it forms the loop of Henle - Then the tubule becomes coiled again (second coiled section is called the distal convoluted tube) - Distal convoluted tube joins a collecting duct that opens up into the renal pelvis (which channels fluid from collecting ducts into the ureter)

Answer 4

Responsible for removing waste from blood and regulating blood composition: - Blood enters the kidney through the renal arteries - Renal arteries divide into smaller arteries and arterioles - Each renal corpuscle is supplied with an afferent arteriole which forms a knot of capillaries called the glomerulus - Capillaries unite to form the efferent arteriole which passes out of the renal corpuscle - After leaving the renal corpuscle the efferent arteriole breaks up into a second capillary network (peritubular capillaries) - These surround the proximal and distal convoluted tubules, the loop of Henle and the connecting duct - Blood drains away from the peritubular capillaries and leaves the kidney the renal vein

Answer 5

1. Afferent arteriole has a wider diameter than the efferent arteriole 2. Afferent arteriole carries blood into the nephron, efferent carries blood away

Answer 6

glomerular filtration selective re-absorption tubula secretion

Answer 7

1. Small substances move from the glomerulus into the glomerular capsule 2. Afferent arteriole leading into glomerulus is much wider than efferent arteriole leaving it 3. This increases resistance in blood flow and creates high pressure in the capillaries 4. Capillaries force water and undissolved blood components through it’s membrane into the glomerular capsule 5. What’s left behind is residue • Blood cells • Proteins

Answer 8

water urea glucose amino acids vitamins salt

Answer 9

1. increasing pressure and resistance in the glomerulus forces substances out 2. Cells of the glomerular capsule and capillaries are 1 cell thick 3. New blood is constantly brought the glomerulus and keeps a concentration difference of the substances

Answer 10

Occurs in tubule of nephron and its surrounding peritubular capillaries Many components of filtrate are useful, so the body uses selective re-absorption to take back what it needs Must be large surface area achieved by: - Long length of renal tubule, created by convolution and lop of Henle - Large number of nephrons in each kidney

Answer 11

proximal convoluted tubule: glucose, amino acids, water, vitamins and salts are absorbed loop of henle: ions are re-absorped to adjust pH to 7.3 - 7.4 distal convoluted tubule: Further reabsorption of water and salt (depending on needs of body) Water is moved by FACILITATED REABSORPTION (active) **permeability of membrane in distal convoluted tubule and collecting duct can be changed so more of less water is absorbed

Answer 12

Body removes unwanted waste and regulates pH levels Substances are secreted back into the tubules: hydrogen ions ammonium creatinine toxins drugs neurotransmitters

Answer 13

inability to tolerate a protein called gluten the immune system responds to this by damaging or destroying villi in the small intestine nutrients cannot be absorbed, and the person becomes malnourished it is inherited symptoms include: nausea and vomiting, stomach cramps, fatigue and weakness treatment: no cure but follow a gluten free diet

Answer 14

glucose + oxygen ----> carbon dioxide + water +energy C6H12O6 + O2 -----> CO2 + H2O + ATP

Answer 15

amino acids + oxygen ----enzymes----> carbohydrate + ammonia energy + carbon dioxide + ammonia ------> water + urea

Answer 16

jelly like material fills space between nucleus and membrane 75 - 90% water cell organelles suspended in it regulate osmotic pressure

Answer 17

largest organelle oval of sphere shaped nuclear membrane: double membrane, separates nucleus from cytoplasm nuclear pore: gaps in the nuclear membrane, lets large molecules enter and leave the nucleus nucleolus: inside nucleus, contains genetic material in DNA, plays a part in manufacturing proteins

Answer 18

very small spherical organelles site of protein synthesis either attached to endoplasmic reticulum or free floating in cytoplasm

Answer 19

pairs of parallel membranes extending from cell membrane to nucleus channels are for storing or transporting molecules e.g. protein provides surface for chemical reactions to take place rough: ribosomes attached smooth: no ribosomes

Answer 20

flattened stacks modifies and packages proteins vesicles: small sacks of liquid containing proteins formed at the edges of the golgi body membrane

Answer 21

small sphere containing digestive enzymes remove/break down cell waste

Answer 22

double membrane (outer and inner folded) sausage shaped some chemical reactions of cell respiration occur provides energy available for cellular activities

Answer 23

controls/regulates movement of particles in & out of cell regulates equilibrium in cell phospholipid bilayer phosphate head: hydrophilic (water loving), head faces cytoplasm and outside of cell (both mostly water) glycerol neck connects to: 2 x fatty chain tails: hydrophobic (water hating), faces inward & not in direct contact with water embedded between the phospholipids are proteins

Answer 24

identity protein receptor protein carrier protein channel protein

Answer 25

passive: no energy required active: requires energy

Answer 26

spreading out of particles from areas of high - low concentration until they're evenly distributed down a concentration gradient only occurs in gases and liquids passive, no energy required occurs across cell membrane only lipid soluble substances

Answer 27

movement/diffusion of water particles from areas of high to low concentration down a concentration gradient through AQUAPORINS water molecules can pass through both phospholipid bilayer and channel proteins.

Answer 28

facilitated: passive, with concentration gradient H-L, water soluble, requires assistance e. g. glucose molecules simple: passive, with concentration gradient H-L, lipid soluble, straight through membrane e. g. O2, CO2

Answer 29

diffusion and osmosis

Answer 30

requires energy (ATP: adenosine triphosphate) against concentration gradient L-H example of active transport: vesicular transport e.g. transporting ions

Answer 31

movement of substances across the membrane in membranous sacks called vesicles active process: energy is needed to form the vesicles either endocytosis: taking substances into the cell by vesicular transport. membrane forms around particle until completely enclosed. Vesicle pinches off and is suspended in the cytoplasm. In pinocytosis (liquids) or phagocytosis (solids) exocytosis: contents of a vesicle inside the cell are passed to the outside. a vesicle migrates to the membrane and fuses with the membrane. contents of the vesicle are the pushed outside of the cell.

Answer 32

muscular epithelium connective nervous

Answer 33

cells are arranged in sheets joined by small amount of intercellular matrix rest on basement membrane either: simple epithelium: 1 layer connective epithelium: several layers

Answer 34

squamous cuboidal columnar ciliated

Answer 35

several layers of cells cells become flatter and more scale like closer to the surface cells lose their living contents in the skin found in lining of mouth, pharynx and oesophagus

Answer 36

lines internal organs and cavities protects underlying cells from injury, harmful chemicals, bacteria or drying absorption secretes waste sensation

Answer 37

binds parts of the body together provides support found in: rib cage, ears, and joints between bones

Answer 38

areolar adipose cartilage bone

Answer 39

cells are nearly cube shaped found in the kidney

Answer 40

cells are column shaped long axis at right angle to basement membrane found in lining of stomach and intestines

Answer 41

flattened and scale like arranged edge to edge found in lining of the mouth

Answer 42

short, actively waving threads called cilia are attached to cell edges found in wall of trachea

Answer 43

white and yellow fibres mixed together as well as other non fibrous ground substances keeps internal organs in place and binds skin to deeper structures found in: under skin, binding it to muscle & surrounding various organs

Answer 44

fatty tissue few fibres and cells are swollen with fat droplets protects organs close to it emergency food reserve found: under skin, packed around internal organs

Answer 45

consists of tough matrix cells are spread far apart; lots of cell matrix between them cells continuously divide to multiply each cell produce fresh matrix, spreading them further apart found: wall of trachea

Answer 46

very firm connective tissue cells are separated by matrix of organic material made up of groups of concentric layers of lamellae surrounding the Haversian canal (contains blood vessels and nerves) in between lamellae lie small cavities, lacunae lacunae is united with Haversian canal through canaliculi which run through the lamellae

Answer 47

has the power of contraction made up of fibres 3 types: striped/skeletal/voluntary unstriped/plain/involuntary cardiac

Answer 48

builds muscles under control of will includes most 'meat' or 'flesh' of an animal

Answer 49

builds muscle not under control of will e.g. in the walls of gut and walls of blood vessels capable of sustaining slow contractions even when separated from nervous system sensitive to mechanical stimulation e.g. stretching

Answer 50

only found in wall of heart no sarcolemma and have faint cross striations cells are not properly divides into seperate units, they branch and join with neighbours so a network is formed

Answer 51

consists of nervous cells or neurones has supporting tissue called neuroglia found: in brain

Answer 52

determine which type of cell it is

Answer 53

fit with specific molecules to help carry them across the membrane

Answer 54

assist molecules moving across the membrane easily

Answer 55

open and allow larger molecules to travel across membrane

Answer 56

Physical process of inhalation

Answer 57

External intercostals contract --> ribcage moves up and out Diaphragm contracts and flattens Volume of thoracic cavity increases - Lungs inflate, increasing volume in the lungs - Therefore decreasing pressure - Air travels from H-L pressure into the lungs

Answer 58

Internal intercostals contract --> ribcage moves down and in Diaphragm relaxes and forms a dome shape Volume of thoracic cavity decreases - Lungs deflate, decreasing volume in the lungs - Therefore increasing pressure - Air travels from HL pressure out of the lungs

Answer 59

Covered by the pleural membrane The inner layer is attached to the lungs and the outer layer attached to the thoracic cavity Between the 2 layers is the pleural fluid It’s attached to the thoracic cavity and reduces friction, protects them as we breathe

Answer 60

Divides into 2 sides, each side has 3 shelves Contains chemo receptors Cilia hairs filter. Blood capillaries warms. Mucous moistens.

Answer 61

Allows for speech, vocal cords vibrate to make sound.

Answer 62

Made of c-shaped bands of cartilage that give flexibility and support Lined with mucous membrane and cells with cilia to trap any solid particles Cilia beat to move mucous and trapped particles upwards

Answer 63

Pass air from the trachea into each lung. Contains cartilage rings and a ciliated mucus membrane Two bronchi branch from the trachea, one left and one right

Answer 64

Very fine tubes that pass air from bronchi to alveoli. End in tiny air sacs, the alveoli.

Answer 65

Tiny air sacs at the end of bronchioles Site of gas exchange On the outside of an alveolus is a dense network of blood capillaries One cell layer thick Cells are moist to increase the rate of diffusion The huge surface area allows efficient exchange of gasses

Answer 66

Process of oxygen diffusing from the alveoli into the blood and carbon dioxide diffusing from the blood into the alveoli in the lungs.

Answer 67

Deoxygenated blood comes from the heart via pulmonary artery. There is a high concentration of C02 in the blood capillaries and a low concentration in the alveolus. Inspired air in the alveolus contains a high concentration of oxygen, and low in the blood capillaries. Via the process of diffusion carbon dioxide moves from the capillaries (high concentration) to the alveolus (low concentration). O2 moves from the Alveolus (high concentration) to the blood capillaries (low concentration). Oxygenated blood in the capillaries returns to the heart via pulmonary veins. C02 in the alveolus is expired.

Answer 68

1. Alveoli give the lungs a huge internal surface area, so large amounts of gas can be exchanged more efficiently and quickly 2. Each alveolus is well supplied kwith blood vessels, so that as much blood as possible is close to air 3. Alveoli and capillary cell walls are 1 cell thick, so molecules don’t have to travel far when moving in or out of the blood 4. Lung volume can be changed by movements of respiratory muscles, so air is made to flow in and out of the lungs

Answer 69

emphysema asthma

Answer 70

Caused by long term exposure to irritating particles in the air taken into the lungs Irritating particles cause damage to alveoli They lose elasticity and are replaced with fibrous tissue and may break down, reducing surface area for gas exchange Lungs become constantly inflated and breathing out is a voluntary effort Symptoms: frequent coughing/wheezing, cough produces mucous, tightness in chest, shortness in breath especially in physical activity Treatment: cannot be cured, once lung damage begins progression of disease cannot be stopped

Answer 71

Difficulty breathing caused by narrowing of airways Occurs due to: smooth muscles contracting: blocking airways, mucous filling airway, narrowing the tube Triggers include: respiratory infections, cigarette smoke, allergens e.g. dust, pollen and animals During asthma attack muscles surrounding the bronchi spasm and cause narrowing of air passages, therefore difficult breathing Irritation of membrane lining passage secretes excess mucous, restricting movement of air Gas exchange is reduced and blood doesn’t carry normal amount of oxygen Symptoms: difficulty breathing, severe chest pain, coughing and wheezing Treatment: bronchodilator, inhaler, anti-inflammatory medication

Answer 72

3% is dissolved in blood (plasma) 97& dissolved in oxyhaemoglobin - At the alveoli oxygen enters into RBCs and attatches to the ‘haem’ part of the haemoglobin molecule - At the cells oxygen breaks off the haemoglobin molecule and enters fluid outside of the cell, the moves into the cell

Answer 73

8% dissolved in blood (plasma) 22% dissolved in the ‘globin’ part of haemoglobin in RBCs - At the cells 22% of CO2 attached to the globin part of the haemoglobin molecule - At the alveoli CO2 breaks away and moves into the alveoli to be exhaled 70% converted into bicarbonate ions - CO2 diffuses out of cell and react with water around the cell to form carbonic acid - Carbonic acid ionises to produce H+ ions and HCO3- ions - At the alveoli this reaction reverses

Answer 74

CO2 + H2O (arrows) H2CO3 (arrows) H+ + HCO-3

Answer 75

Body’s main transport system Link between cellular requirement inside the body and outside environment that supplies these requirements Blood is the transport link between cells and all the body systems Some important functions of blood are: - Transporting oxygen, nutrients and hormones to cells - Transporting carbon dioxide and waste away from cells - Maintaining pH and water & ion concentration of body fluids - Distribution of heat and maintaining body temperature

Answer 76

Pump that pushes blood around the body Located between the lungs in the mediastinum & behind and slightly to the left of the sternum Conical shape approximately 12 cm long, 9 cm at its widest and 6 cm wide It is enclosed in the pericardium (its membrane) Wall of heart is made of cardiac muscle Right side: collects deoxygenated blood from the body and pumps it to the lungs Left side: collects oxygenate blood from the lungs and pumps it around the body Each side is separated into 2 chambers: atria & ventricles

Answer 77

- Holds heart in place - Allows for movement - Prevents overstretching

Answer 78

composition in blood: 45% Biconcave disc shape No nuclei: more room to carry haemoglobin that binds with oxygen Flexible: fit through capillaries Carry oxygen, bound to the protein haemoglobin Live for approximately 120 days Produced in red bone marrow destroyed in liver and spleen

Answer 79

composition: <1% Larger than RBC but fewer 2 types: - Granulocytes: granular cytoplasm and spherical nucleus - Monocytes and lymphocytes: agranular cytoplasm and spherical nucleus Able to change shape Removes dead/injured cells and invading

Answer 80

composition: 55% 91% water The rest is dissolved substance e.g. ions, gases, hormones Pale yellow colour Liquid part of the blood

Answer 81

composition: <1% small cell fragments no nucleus formed in red bone marrow last for 7 days jagged edges

Answer 82

Minimise blood loss prevent entry of microorganisms

Answer 83

vasoconstriction platelet plug formation coagulation

Answer 84

Blood Vessel constricts reducing blood flow to that area.

Answer 85

Walls of blood vessel becomes rough Platelets in plasma become stuck to the rough walls More platelets come to the site and stick to each other Platelets release chemicals which prolong vasoconstriction

Answer 86

Chemicals form thread-like proteins called Fibrin Fibrin threads form a mesh network around the plug Fibrin seals wound from outside the blood vessel wall and traps RBCs This build up causes a clot Network of threads contracts and pulls the edges of the damaged vessels together Fluid gets squeezed out of the cut and dries, causing a scab