6. Human Physiology Flashcards
6.1 Bile makeup
Contains bile salts
- interact with fat globules and divide them into smaller droplets
6.1 Stomache acid makeup
- releases digestive acids to create low pH to denature protiens
+ pepsin enzyme
6.1 What is peristalsis?
Muscle contractions along digestive tract
6.1 What is the iluem?
The final and largest section of the small intestine
6.1 Small intestine vs large intestine
Small intestine: usable food substances: monosaccharides, amino acids, fatty acids, vitamins
Large intenstine: water and disolved minerals
6.1 Draw the structure of the iluem
6.1 Draw the digestive system including descriptions
Salvitory Glands: moistion, begin carbohydrate digestion ( amylase )
Esophogus: Transport food via peristalsis
Stomache: Store and churn food, begin protien digestion (protease)
Pancreas: Release digestive enzymes, release hormones
Gall bladder: Store/secrete bile
Liver: Detoxify, stores vitamins, Iron, gylcogen, syntesizes bile
Small I: Absorbs nutrients
Large I: Absorbs water and ions
Rectum: Release of waste
6.1 Types of intenstine muscle contraction
Circular: Contraction behind food to prevent backward movement
Longitudinal: Pushes food along
6.1 Peristalsis in stomache vs intestine
Stomache: One pulse from esophogus to stomache
Esophagus: slow, mix with enzymes
6.1 Glands of pancreas
The pancreas has two gland tissues, exocrine (main) for enzymes and endocrine (smaller) for hormones.
6.1 Enzymes of pancreas
Lipase
Amylase
Protease
6.1 Structure of villus epithelial cells
Tight junctions between cells
Microvilli
More mitochondria
Pinocytotic vesicles
6.1 What is the structure of intestional villi?
Microvilli
Dense capillary network
Single layer epithelium
Lacteal -absorbs lipids into lymphatic system
Inteestinal glands (exocrine pits) release digestive juices
Membrane protiens
6.1 What do intestional villi absorb?
Glucose, fructose, galactose
Any A-acids
Fatty acids, monoglycerodes + glycerol
Bases from nucleotides
Mineral ions
6.1 What are the two way the pancreas breaks down starch?
Exocrine: Amylase from acinar cells
Endocrine: Hormones
6.1 What is the duodenum?
First section of teh S.I which is fed by pancreas and gall bladder
6.2 What is atheroscelrosis?
The build up of fat deposits in coronary arteries
Plaques are created form fat buildup, if these rupter clots form a thrombus
6.1 Where does starch get broken down?
Starts in mouth w/ saliva, not in stomache pH bad, then gets broken down in intestine w/ amylase
Amylose –> maltose
Amylopectin –> dextrins
Both these disaccharides get broken down by maltase fixed to the epithelial lining of the small intestine
6.1 Methods of absorption for the villi
1) NA+ and glucose/amino acids cotransported
2) Triglycerides are broken into fatty acids + monoglyceride which simple diffuse,
Everything diffuses out (monosaccharides facilitated) into capillary, lipids into lacteal
6.2 Types of tissue in arteries
Elastic: Contains elastic fibers which store energy at peak stretch, recoil sends blood down artery
Muscular tissue: determines diameter of lumen
6.2 Structure of artery (description)
Lumen
Tunica Interna
Tunica Media
Tunica externa
6.2 Blood pressure terms
Systolic = peak pressure
Diastolic = resting
6.2 What are capillaries?
Narrowest blood vessels
Form extensive networks
Bring blood to almost all tissues
6.2 Capillary structure
Wall = thin endotheliym cells covered in fliter like protien
6.2 How does exchange with capillaries work?
The permeability of the wall allows part of the plasma to leak out and become tissue fluid. This flows between cells allowing absorption and excretion of waste before it is reabsorped
6.2 Plasma vs Tissue Fluid
Plasma: fluid around red blood cells
Tissue fluid: O2, glucose, other substances (not protiens, too big)
6.2 Vein purpose
Collect blood at low pressure to go back to heart, not thick walls and valves
6.2 Circulation of blood
Systematic circulation: pumps oxygenated blood around body
Pulmonary Circulation: pumps deoxygenated blood to lungs
6.2 Draw a heart
6.2 Heart valves
Tri Me PA
Atrioventricular (AV): Tricuspid (right) , mitral
Semilunar (SL)
Pulminary (right), aortic
6.2 Path of pulmonary circulation
Superior vena cava –> right atrium –> AV valve –> right ventricle (also inferior vena cava enters to ventricle) –> SL valve –> pulmonary artery
6.2 Path of systematic circulation
Pulmonary vein –> left atrium –> AV valve – left ventricle –> SL valve –> aorta
6.2 Cardiac cycle
0-0.1: Atria contracts pushing open AV valves
0.1-0.15: Ventricle contracts, closing AV valves
0.15-0.4: Pressure increases in ventricle pushing open sumilunar valves
0.4-0.45: ventricle relaxes, SL valve closes
0.45-0.8 pressure drops, AV valves open
6.2 Heart beat sound
Caused by AV valves
Lub - close
Dub - open
6.2 Heartbeat pacemaker
Sinoatrial node is a group of speciliazed muscle cells that kicks off a wave of depolarization first in atria
Then 0.1 secs later in vetricles
6.2 Control of heartrate by brain
The cardiovascular center in the medulla has two branches of nerves.
- One increases pase
- The other decreases
Indicators:
Low blood pr, low O, low pH = need speed up
High that stuff = slow down
Epinephrine: hormone that increases pace, from adrenal glands
6.3 Surface barriers of defense
Skin: Extneral structures
tough physical barrer, mostly dead skin cells, sebacious glands secrete sebum (lowers skin pH, inhibits growth)
Mucuous membranes: Internal structures that are externally accesable
traps pathogens, antibacterial enzyme - lysozume
6.3 Clotting process
1) Platelets (cellular fragments) form temperary plug
2) Platelets release clotting factor
3) This triggers conversion of prothrombin into thrombin
4) Thrombin converts fibrogen into insoluble fibrin
5) Fibrin forms mesh around plug and traps blood cells that harden
6) When damage is repaired, plasmin (enzyme) disolves clot
6.3 Coronary Thrombosis
Formation of clot within coronary arteries (blood vessels that sustain heart)
Form when vessels are damaged as a result of cholestoral deposits (atherosclerosis) ruptering
6.3 Role of Phagocytes
Phagocytes are part of the non-specific innate immune system
Phagocytic leukocytes (white blood cells) circulate blood and move through body tissue. Leukocytes are drawn by the release of histamines
Through phagocytosis pathogens are englufed (endocytosis) and the vesciel is fused to a lysosome.
Antigens may be presented
6.3 Types of Leukocytes (white blood cells)
Neutrophils: majority of white blood cells, phagocytosis
- unable to renew lysosome, become pus
ex: police
Eosinophils: prominent at allergic reactions and parasitic infection (common in mucus, not blood)
- release chemicals to perforate cells
ex: pest control
Basophil: mainly responsible for initiating inflamattory response by releasing histamine
- Similar to mast cells but circulate in bloodstream
ex: Fireman
Monocyte: share phagocytosis duties, slower but longer lasting
Will differentiate into two types of cells in response to infection
-Macrophage: remain in tissue and phagocytosis, riot police
-Dendritic cell: present antigen fragments to lymphocytes
Lymphocyte: antibody production
- B Cells (plasma + memory)
- T Cells (helper, cytotoxic)
ex: superheros
6.3 Role of antibiotics
Target bacterial DNA replication, transcription, translation, ribosome function and cell wall formation
- Mainly discovered in saprotrophic fungi
6.3 Antibiotics and viruses
Viruses have no metabolic processes no antibiotics do nothing
6.3 Development of antibioirc resistance
Process:
Natural selection, fast reproduction, horizontal gene transfer (plasmids)
Factors:
Over prescription, no presciption use (over the conter), common in hospitals
6.4 Draw a diagram of alveoulus and adjacent capillaries
6.4 Types of pneumocytes
Type 1: Most cells in epithelium are type 1
Type 2: Secrete solution to keep alveoli moist
- form monolayer (similar to phospholipids) on surface of wet alveoli
- Reduces surface tension and prevents water escaping
6.4 Draw a diagram of alveoli
6.4 Process of inspiration
Primary muscles: Diaphragm and external intercostal
Diaphragm contracts, becoming flat and increasing volume of thoracic cavity
External intercostals contract, pulling ribs up and out
6.4 Process of expiration
Primary muscles: abdominal and internal intercostals
Abdominal muscles: As diaphragm relaxes, abs conract and push diaphragm upward
Internal intercostals: pull ribs downward and external muscles relax
6.4 Lung cancer
Causes:
Smoking, air pollution, infections, genetic predispositions
6.4 Emphysema
Lung conditinon caused by damage to alveolar walls.
- Leads to loss of elasticity for alveoli which causes abnormal enlargement
- Smaller number of larger air saces = reduced SA
Major cause = smoking
6.5 Draw a nueron cell
6.5 What is the difference between the endocrine and nervous system?
Endocrine = hormones
Nervous = nuerons
6.5 What are the two types of growth from nueron cells?
Dendrites: Short-branched (between other nuerons)
Axons: Elongated
6.5 What are myelinated nerve fibers?
Some nerve fiber are coated with myelin
Schwann cells grow around nerve fibers, each time they grow a double layer of phoslipid bilayer
- the gap between myelin is called node of Ranvier
6.5 Resting potential of a nueron
Nuerons not transmitting have a resting potential caused by a natural imbalance
6.5 What causes the resting potential of a nueron?
Sodium-potassium pump: pumps NA out and K in to maintain charge
K+ ions leak back across faster than Na+
Negatively charged prtoeins inside increase imbalance
6.5 Concentration of ions during resting potential
More K+ inside, more Na+ outside
3Na, 2K
6.5 Stages of action potential
Depolarization: Sodium channel opens, Na goes inside, membrane potential becomes positive
Repolarization: Potassium channels open, potassium moves outside (negative again, but opposite with Na inside and K outside)
Refractory Period: Other channels closed, Na+/K+ pump brings K in and pushes Na out
6.5 What are nerve impulses?
Propogation of action potentials from one end to the other of a nueron
Depolarization triggers neighbors depolarization
6.5 What are local currents?
Diffusion of Na+ with its depolarized part and non-depolarized neighbor
6.5 What are synapses?
Junctions between nuerons or nueron and receptor (effector) cells
6.5 Steps of transmission at synapses
1) Action potential arrives at axon terminal
2) Voltage-gated Ca2+ channels open (because of depolarization)
3) Ca2+ enters presynaptic nueron
4) Ca2+ singals to nuerotransmitter vesicles
5) Vesicles move to membrane and release transmitters via exocytosis
6) Nuerotransmitters bind to receptor
7) Ligand-gated ion channels open
8) Sodium ions diffuse down gradients and cause post-synaptic memrbane to reach threshold potential
9) Depolarization triggered
10) Nuerotrasnmitters broken down and removed
6.5 What is acetylcholine?
A common nuerotransmitter synthesized in pre-synaptic cell w/ choline (diet) and acetyl (respiration)
Acetylcholine remains for a short time in receptor before acetylcholinesterase breaks it down, choline reabsorbed
6.5 What are neonicotinoids?
These molecules bind to acetylcholine-receptors and can’t be removed w/ enzyme
- effective insecticide
- toxic to humans
6.5 What is the threshold potential
Action potentials only happen when threshold potential is reached, voltage-gated sodium channels open then
- Amount of nuerotransmitted secreted may not be enough to cause threshold potential
- Typical post synaptic nueron has multiple synapses, may require several nuerotransmitter releases
6.6 How are glucagon and insulin secreted?
From pancreatic pits called islets of Langerhans
Insulin comes from beta cells
Glucagon from ALpha cells
6.6 Type 1 vs Type 2 Diabetes
Types 1: Body fails to produce insulin, treated with injections
Type 2: Failing to respond to insulin production, monitoring dietary intake
6.6 What is thyroxin and how is it secreted
Thyroxin is secreted by the thyroid gland in hypothalamus
- increases basal metabolic rate
Needs iodine, defficency is bad
6.6 What is leptin and how is it produced?
Leptid is produced by adipose cells and it supresses appetite
6.6 What is melatonin and how is it produced?
Produced by pineal gland, light exposire inhibits melatonin secretion
6.6 How is male sex determined?
On the Y chromosome the SRY gene codes for TDF which causes development of testes, these produce testosterone to further dedvelopment
6.6 How is female sex determined?
In absence of SRY, ovaries will develop instead and those will secrete estrogen and progesterone
6.6 Draw the male reproductive system
6.6 Draw the female reproductive system
6.6 What is FSH, where is it produced and when?
Produced by anterior pituitary gland
- stimulates follicular growth
- stimulates estrogen secretion
Peaks right before ovulation / less than LH
6.6 What is LH?
- surge causes ovulation
- results in formation of corpus luteum
Anterior pituitary
Surges high at ovulation
6.6 Purpose of estrogen
Secreted by ovaries
- thickens endometrium
- inhibits FSH and LG
- stimulates FSH and LH pre ovulation
Rises over follicle cycle, peaks at ovulation, high during luteal
6.6 Purpose of progesterone
Thickins endometrium
Inhibits FSH and LH
Anterior pituitary
Highest at luteal phase
6.6 What two hormones is the posterior pituitary gland responsible for?
ADH
Oxytocin
