C3.1 Integration of Body Systems

kms

system hierarchy of organisms (5)

specialized cell

tissue

organ

organ system

organism

variety of cells in tissues (2)

• may contain only 1 type of spec. cells or multiple spec. cells

• eg. AT1 and AT2 cells in lung epithelium

human body systems (11)

• digestive

• integumentary

• nervous

• reproductive

• skeletal

• lymphatic

• muscular

• circulatory

• endocrine

• gas exchange

• urinary

diffs btwn hormonal and nervous signalling (5 counting both types)

	hormonal	nervous
type of signal	chemical	electrical
transmission	bloodstream	neurons
response speed/length	slow, long lasting	VERY fast, short term
destination of signal	widespread	focused
effectors	target cells (tissues)	muscles/glands

types of hormone responses (5)

• growth + dvlpmt

• reproduction

• metabolic rate

• homeostasis (glucose reg)

• mood, stress, thirst, sleep, horny, etc

types of nervous responses

• muscle contraction (striated, smooth, cardiac)

• gland responses

  • exocrine (eg. sweat)

  • endocrine (eg. adrenaline)

role of brain as an organ

• central integrating organ connecting all life processes

• receives info from sensory organs

• sends signals to muscles or glands to carry out responses

anatomy of spinal cord (5)

• white matter myelinated

• grey matter not myelinated

purpose of each part of spinal column (4)

white matter: carry impulses to/from brain

grey matter: unconscious processes and reflexes (faster than going up to brain first)

dorsal root: contains axons of sensory neurons

ventral root: contains axons of motor neurons

nerve anatomy (5+1)

• most nerves contain nerve fibres of both sensory and motor neurons but some only contain 1 or the other

pathway of signals in grey matter (3)

• neurons bring info to grey matter from brain and sense organs

• motor neurons convey signals from grey matter to muscles and glands

• interneurons pass impulses via synapses btwn neurons in grey matter

unconscious vs conscious processes

unconscious	conscious
can happen when asleep	only happen when awake
involuntary	voluntary
controlled by brain and spinal cord	controlled by cerebral hemispheres of brain
glands and smooth muscle controlled involuntarily	striated muscle controlled voluntarily
eg. peristalsis in intestine	eg. chewing

types of neurons relating to sense (5)

receptor cells: detect changes in phsyical envr

• stretch receptors: sense state of contraction in muscle

• chemoreceptor: monitors chemicals in blood

sensory neurons: transfers impulses from receptors to central nervous system

interneurons: connectors btwn sensory and motor neurons

pathway of sensory neurons (3)

• sensory neuron axons enter either spinal cord or brain

• brain receives signals from main sense organs in the head (eyes, ears, nose, tongue)

  • sensory inputs to brain received by specialized areas in cerebral hemispheres eg. visual cortex receiving info from rod and cone cells in eyes

pathway of control of muscles (3+1)

• motor cortex sends nerve impulses to any striated muscle

• striated muscle attached to bone can move

• equals ctrl of posture + locomotion

• (extra) grey matter in cerebral hemispheres contains many motor neurons

reflex arc (2)

rapid involuntary response to a specific stimulus

• signals pass thru the smallest # of neurons = fast and advantageous

where do reflex arcs go

spinal cord or brain synapses (bc fast)

pain reflex arc (6)

1. pain stimulus

2. sensory receptors detect sitmulus and generate impulse

3. sensory neuron conducts signal to CNS

4. impulse is sent thru interneurons that send it to the brain

5. brain sends impulse to motor neurons, which conduct it to the effector

6. effector muscle produces a response (flinch away)

parts of cerebrum (6)

roles of each cerebrum part (6)

frontal lobe: mvmt and control

temporal lobe: communication, hearing, memory

parietal lobe: touch and sensory input

occipital lobe: visual processing

cerebellum: skeletal muscle ctrl, balance, precise ctrl of mvmts

brain stem: vital body fxns (eg. breathing and heart rate)

parts of inside brain??? (5)

function of inside brain things idk (3)

hypothalamus: endocrine system

pituitary gland: hormone production

corpus callosum: communication btwn left and right hemispheres

circadian rhythm process (6)

1. light detected by retina which sends impulses to suprachiasmatic nucleus

2. SCN of hypothalamus signals to pineal gland

3. pineal gland reduces secretion of melatonin

4. lack of light detected by retina

5. SCN signals to pineal gland

6. pineal gland increases secretion of melatonin

times of day for melatonin stuff (2)

7:30am: melatonin secretion stops thru liver removing it from blood

9:00pm: melatonin secretion starts

effects of low melatonin (6)

• ++ body temp

• ++ blood pressure

• ++ alertness

• ++ muscle control

• ++ strength

• ++ rxn time

efects of high melatonin

• -- body temp

• -- BP

• ++ sleepiness

• -- urine production

hypothalamus

links nervous system to endocrine system via pituitary gland

nuclei (biology) (2)

• specialized areas in hypothalamus

• uses info from a variety of sources (eg. sensors for blood temp, glucose conc. etc)

pituitary gland (3)

• responsible for hypothalamus system integration (eg. puberty, osmoregulation

• does this by secreting hormones to blood caps

• ctrled by hypothalamus

things secreted by the pituitary gland

anterior lobe	posterior lobe
HGH — growth LH — ovulation FSH — follicle stim. TSH — metabolism prolactin — lactation	ADH — osmoregulation oxytocin — love

adrenaline response (4)

1. stimulus triggers fight/flight response (preparing body for vigorous physical activity)

2. signal triggers adrenal glands

3. pituitary gland releases adrenocorticotropic hormone (ACTH) which also triggers the adrenal glands

4. medulla of adrenal glands secrete adrenaline into bloodstream

location of adrenal glands

on the kidneys like hats

what places are affected by adrenaline response (6)

• striated muscle fibres

• SA node

• liver

• arterioles

• lungs

• non-essential functions eg. digestive system and urination

effetcs of adrenaline on striated muscle fibres

converts glycogen into glucose for cell resp

effects of adrenaline on SA node

incr. bpm = incr blood flow, O₂, energy (from resp)

effects of adrenaline on liver

converts glycogen on glucose (ie. increases glucagen)

effects of adrenaline on non-essential functions

slows digestion, urination so that blood goes to the heart and lungs

effects of adrenaline on arterioles (2)

• blood going to muscles and liver vasodilate (WIDEN) to incr. blood flow

• blood gonig to gut, kidneys, skin vasoconstrict (shrink) = red. blood flow

effects of adrenaline on lungs (2)

• bronchioles dilate to make vent. easier

• intercostal and diaphragm muscles contract at a faster rate and more force = incr. vent rate, O₂

cumulative result of adrenaline (2)

• striated muscles get a greater volume of blood per min

• results in incr. resp = incr ATP = incr. frequency and/or power of muscle contractions

baroreceptor

responds to blood volume and pressure in arteries

chemoreceptor (2)

responds to blood pH, which indirectly monitors blood O₂

• CO₂ → HCO₃ = -- pH = -- O₂

control of heart rate by brain (4+1)

1. BR and CR monitor for changes in blood

2. (A) cardiovascular centre (CVC) in medulal oblongata ctrls freq. of impulses in parasympathetic nervous system along the vagus nerve = --- bpm

3. (B) CVC ctrls freq. of impulses in sympathetic nervous system = +++ bpm

4. causes the sinoatrial node to set the heart rate by initiating each beat

• extra: signals from hypothalamus can also signal adrenal glands to secrete epinephrine (+++ bpm)

locations of BR and CR (2)

BR: carotid artery and aorta

CR: carotid artery

control of ventilation by brain (3)

1. CR monitor blood pH

   • CR in carotid monitor [O₂] of blood flowing to brain

2. respiratory centre in brainstem sends signals to diaphragm and external intercostal muscles to contract = inhale

3. RC sends signals to abdomen wall muscles and internal intercostal muscles to contract = exhale

role of nervous systems in ventilation (2)

PNS: -- vent rate

SNS: ++ vent rate

peristalsis

waves of contraction and relaxation in wall of gut that moves food from mouth to stomach to intestines to anus

control of peristalsis in brain (5)

1. stimulus of bolus (chunk of food)

2. stimulation of enteric nervous system (which is the autonomous NS)

3. contraction of circular muscles BEHIND bolus; longitudinal muscles relaxed

4. contraction of longitudinal muscles AHEAD of bolus; circular muscles relaxed

5. repeat CM, LM contraction in a cycle to push bolus along tract

digestive things that CNS voluntarily controls

• swallowing

• defectation

how swallowing happens (3)

• striated muscle in tongue that pushes food to bacck of mouth

• food stimulates touch receptors in pharynx that are passed to brainstem

• stimulates muscle contr. to push food into esophagus

how defecation happens (3)

• anus contains a ring of smooth muscle (sphincter)

• wall of rectum contains layers of CM and LM

• during defecation, anus widens and wall of rectum contracts to push feces out

tropism and types (3)

turning all or part of an organism in a particular direction in response to stimuli

phototropism: growth in response to light

gravitropism: growth in response to gravity

phototropism in root vs shoot (2)

root	shoot
negative tropism: auxin accumulates on dark side = root grows down (away from light)	positive tropism: auxin accum. on dark side = shoot grows up (towards light)

gravitropism in root and shoot (2)

root	shoot
positive tropism: auxin accum. on lower side = root grows down (towards gravity)	negative tropism: auxin accum. on lower side = shoot grows up (away from gravity)

types of phytohormones and uses

gibberellins: ctrl. cell elongation for stem growth, seed germination, flowering, plant dormancy

ethylene: ctrl. fruit ripening

cytokinins: incr. rate of cell division

auxin: ctrl. cell elongation

jasmonic acid: secretion of enzymes to digest prey in Venus flytrap

auxin efflux response (4+1)

1. auxin enters cells by passive diffusion ONLY if its carboxyl is uncharged

2. cytoplasm of plant is alkaline so auxin loses H⁺ from carboxyl group, making it a negatively charged COO^-; this traps it in the cell

3. auxin efflux carriers can pump -ve auxin molecules across PM into the surrounding cell wall

4. cell wall is acidic so auxin regains H⁺ to turn into uncharged state

• auxin is pumped in the same direction by all cells, resulting in a conc gradient being generated

cellulose structure (3)

• cellulose microfibrils are the main structural component of plant cell walls

• inelastic so they cant stretch/extend; instead they move further apart or slide past e/o

• crosslinked in cell walls by carbohydrates; the strength of these crosslinks is determiend by pH (-- pH = -- link str)

how auxin causes cell growth (4)

1. auxin binds to receptors on H⁺ pump

2. H⁺ pumped into cell wall

3. decreased pH reduces links of cellulose structure, causing expansion

4. H₂O enters cell allowing it to elongate

where are auxin and cytokinin generated and go (2)

auxin: produced in shoot, goes to root in phloem

cytokinin: produced in root, goes to shoot in xylem

interactions of auxin and cytokinin (4 including both)

	cell division	cell enlargement	dvlpmt of roots	dvlpmt of lateral buds
auxin	stimulates (if CK present)	stimulates	inhibit	stimulate
cytokinin	stimulate	stimulates (if auxin present)	stimulate	inhibit
interaction	synergistic	synergistic	antagonistic	antagonistic

elongation of roots (5)

• incr [A] = inhibit growth

• decr. [A] = incr growth

• whatever side auxin ISNT on will grow and elongate

• therefore, if root grows straight down, auxin is evenly distr. = growth straight down

• if root is angled, auxin accum. on lower side so the lower side is inhibited and the top side grows = downwards growth

elongation of shoots (6)

• incr [A] = incr. growth

• decr [A] = decr. growth

• light directly above = equal auxin distr = grows straight up

• angled = auxin goes to dark side = incr. growth to angle towards light

• auxin also inhibits growth of axillary buds to allow main to grow big (no competition)

• if main shoot is gone auxin is decreased, causing bud growth to replace the lost shoot

what happens to a fruit during ripening (4)

• flesh softer

• acids and starch turn to sugar

• skin colour changes

• nice scents to entice animals

positive feedback loop of fruit ripening (4)

1. ethylene produced by ripe fruit

2. ethylene diffuses into air and goes to other fruit

3. nearby fruit begin ripening too and release ethylene

4. more fruit ripens

5. repeat