Homeostasis

What is homeostasis

maintenacne of constant internal and external changes

What is homeostasis based off of?

Feedback system

What does homestasis ensure?

cells/tissues/organs fucntiosn as normal limits

Give an example of a feedback system

Temeprature:
Temperature outside body gets colder
modey loses het
3 responses - contriction of blood vessels, curling up, shivering
first two limits the heat loss fromt he body
third produces heat

What are the two types of ways the feedback mechanism is regulated through?

Nervous and hormonal

Explaint he process of a general feedbakc system

stimulus - receptor - integrator - effector - responce - negative or positive reesponse to the simulus

Expalin the difference ebtween a pos and neg feedbakc responce

Negative feedback lesens he orgininal stimulus (reverses the effect), positive feedback inhances or amplifies the the original stimulus

Give an example and expalina neg feedback response

Insreased blood pressue →
message sent to brain (integrator) →
brain sends message to the heart and blood vesesl (effectors)→
heart rate increases, vessel diameter increases (response) →
blood pressure decreases to nromal

Give an example and expalin a positive feedback response

Cildbriths, babay head pushes on uterus opening →
pressure causes contractions and sends message to hypothalamus (integratore)
oxytocin is released to increase strength of contractions (response) →
hels push the baby out

Explaint he functions of the kidney

filter blood
remove waste
controll water ballance
controll ph
ontroll ion concentration

what si a filtration unit called int he kidney?

Nephron

Name the 5 parts of the nephron

1. bownmans capsule

2. Proximital tubule

3. loop of henle

4. distal tubule

5. collecting duct

Explaint the bowmans capsule and its fucntion

bowmans capsule contaisn the glomerulus (a bed of capilaries)
blood rpessure in glomeruslus forces plasma and small moleculres out of capilaries and into the bowmans capsule where the fluid is now called “filtrate”

bowmans capsule captures the ions plasma and monomers the ooze out fo the blood

Explaint the Proximital convulated tubule capsule and its fucntion

its is the frist covulated tubula of the nephron

1. reabsobption of materials needed by the body. (glucose, amino acids, ons, water)

2. ph of filtrate adjusted

3. glucose, amino acids and ions are actively transported back into the blood

4. toxins from protien digestion are secretes from blood into nephron

Explaint the loop of henle and its fucntion

regulated fluid balance int eh blood by moving water and ions our of loop o fhenle
concetrates unrine so you only peeing things your DONT need

Decesing limb:

• as fluid decesnds water is passively reabsorbed into surounding fluid that has a higher solute conceptration

• water quickly absorbed by blood stream to maintain blood pressure and ion concentration

• filtrate becomes super concentrated att eh bottom of loop after all that water is taken

Ascending limb:

• is not permeable to water

• as filtrate travels up ions (na, cl and k) are moved out of nephron and into fluid surounding loop keeping the concentration of solute higher outside th elimb

Explaint the distal convulated tubule and its fucntion

mainataind blood ph and electrolye balance by reabsolbing ions or secreation of ions

Explaint the collecting duct and its fucntion

remaining water, ions and waste products are caried to the collectin gduct

water mill move out of collecting duct because of the high solute concentration in the surounding solution (this concentrates the urine)

urine collected and delivered to bladder

why is water quickly absorbed by the blood stream in the descending limb?

to prevent reabsobtion in the nephron

Name the absorebed or released particles of each part fo the nephron

bowmans capsule - plasma, iona, water, glusoce/amino acids
proximal tubule - glucose, amino acids, ions, water
loop of henle - water, ions
distal tubule - ions
collecting duct - water

Ho wis urine production controlled?

fluid intake is detected by hypothalamus (brain) →
sends a signal to the pituitary gland →
decreases the levels of antidiuretic hormone (adh) →
increases urine production

How does the body stop water from leaving the system through urine?

pituitary glad snglans for more adh which makes the colecting duct more permeable to water

Nervous system is split ito what two parts, epain thier difference

Central (CNS) and peripheral (PNS)

CNS:

• recieves sensory info from PNS

• Sends motorcommands back to PNS to react or respond

• braina nd spinal cord

PNS:

• sends sesory info to CNS

• Recieves motor commands from CNS

• motor and sensory nerves

the motor neurons have 2 types

autonimic and somatic

explain autonomic nervous system

controls body organs not under consious controll

heart and stomach, diaphram

(sympathetic and parasympathetic)

Somatic nervous sytem

under cosious contrlll

moving skeletal muscles

Explain difference bwteeen the two typesof autonomins sytem

sympathetic: HHBR

• prepare body for imidiate threats

• increase heart rate and breathing

• glucose relseased form liver for enegry

• releases hormones

Parasympathetic

• actions opposed the sympathic system

• when threta has bpassed stabalizes back to hemostasis range

explain the reflex arc

reflexes are controlled at the spinal cord without the brain

impulse is deted by resceptors and skin

impulse travels directly to spinal cors through sensory neuron

message transmitted staright ti motor neuron through inter neurons (effector)

motor neurons trogger response ebfore barine evn knows whats happening

What is a bundle of neurons

Nerve

WHat are the 3 type sof neurons

Sensory - detects stimulus, send ssignals tot he brain

Interneuron - relays info between sensorya nd motor neurons

Motor - tranmists impuls from bran to muscles/organs

Explain the parts of the neuron

Head:

• cell body

• denrites

Body/Axon:

• Myelin

• Node of ranvier

Feet / Axon terminals:

Expalint he purpose of each partof the neuron

Dendrite: Recieve singla from other neuron

Axon: intramit info in response to stimulus

• node ranvier: has the movement of sodiaum and potassium ions deeded for message to be transmitted

• myelin fat: potects the axon from damage and inscreases the speed of message transmission

Axon terminal: release checmisla neurotransmistters to stimulate the next neuron

What is an action potential

the rapid electrical current transmitting nerve impulses

How doe sthe electric current happen?

Through movement of sodium and potassium in and out of the axon’s cell membrane

what triggers and action potntial?

a certain threshhold of intesity in stimulation

Do axons transmit strong or mild responses?

no the response is unifrom on non existent. You feel the intesity of something by the number of axons firing, not the strenght of the action potential.

Explaint he phases of an action potential

Resting: more sodium actively pumped (leaving) that potasium enetering, potensial of -70mV (3:2)
Depolarization: Stimulus causes na channel to open, (higher con outside) na diffuses into neuron -70 → +40

Repolarization: K channels open immediately after, K diffuses out of neuron to re-establish the resting potentional

Refractory period: for 1 milisecond no channels can be opened by a stimulus (can fire another response)

Resting state again

why are myelinated axons important?

fatty insulation allows for the signal to jump over instead of carry through, this speeds of timing. action potential jumps form node to node

What are the synapses?

Synapeses are th espaces between neurons. nEURONS DONT TOUCH.

How are messages recived and given wehn neurons dont acc touch?

presynaptic neurons release neurotransmitters across the empty space "(synapse) that are recives by postsynaptic neurons via receptos

How does the action potential continue between two neurons?

action potential at the end of a neuron opens CA2 gates. Ca2 triggers the release of neuro transmitters. Neurotranmitter at post synaptic neuron causes NA channels to open, continuing the action potential

(Neurotransmitters are then released and uptaken byt he presynaption enuron again)

Eplain the feedback process of nerves

The stimuls triggers the sesory neuron with relays th emessage to the spinal cord, then ot the brain, a response is created adn relayed to the motor neuron that then takes action. In the case of a relfec, the sensory neuron imidiately triggers the motor neorn

all fo this is transmitted through neurons by an action potential

Explaint he parts fo the brain

Cerebral cortex:

• frontal, parietal, temporal, occipital (Lobes)

• Most high developed part of brain

• thinkign processinf, language

Cerebellum:

• little brain, much older

• Regulation of movement, posture and balance

Brain stem:

• vital life funtions

• Midbrain, pons, medulla

Expaln 2 purposes of each lobe of the brain

Frontal:

• planning

• speech

Parietal:

• spatial orientation

• visual perception

Occipital lobe:

• visual porcessing

• recognizing colour

Temporal:

• Perception of auditory stimulu,

• memory

What are the two hemispheres of the brain connected by, and why?

Left and right are connected throught eh corpus collosum: nervs that ensure communication between sides

Where si the brains tem located

Under the limbic system

Explain 3 functiosn fo the brain stem

Breathing, hreat rate, blood pressure

Why can damage to the brains tem be dangerous?

because its responsibel for vital life funtions

Explain 2 functiosn fo each part fo the brain stem

Mid rbaing:

• voluntery motor functions,

• vision,

• hearing

Pons:

• Motor control,

• sensory analysis,

• consious ness,

• sleep

Medulla:

• breathing,

• heart rate,

• blood flow,

• swallowing

I breief, what is the nedorcin ssytem>?

a collection of glands that secrete hormones

How are the ndocrine and nervous sytem conencted?

Both maintian homeostasis, nervous sytem signals release fo hormones from endocrine glands

Explaint he differences ebtween nervous and endocrine system

Endocrien is slower and longer lasting

Nervous, is faster, imperminent

WHat are hormones?

Chemiscal sproducesd the bodyt hat regialte cell / organ activity

Explain how hormones work

secreted by specialized glands

travel through bloodstream to affect targeti cells by binding to recpetors

What type of feedbakc system are hormones?

mostly negative, one the problme is corrected, pituitary gland stops releasign hormones

WHat are the 7 glands? and where

Hypothalamus/pituitary: Brain

Parathyroid:

Thyroid: Throat

Adrenal - kidney

Pancreas

Pineal: brain

Gonads: testes, ovaries

eXPLAIN THE MASTER GLANDS

Hypothalamus releases releasing hormones that tell the pituitary glad to release hormones

Expalint he 2 parts fo pituitary gland

Postierios:

• ADH (pee)

• Oxytocin (preganancy)

Anterior:

• TSH (Thyroid growth, and thyroid hormones secretion

• ACTH (stimulates adrenal cortec - stress)

• FSH (egge developemnt and sex hormones in women and sperm production

• LH (regulated ovulation in females and secretion of sec hromones in males

• HG (growth

• PRL (breast dev and millk produc

• Endorphins (Nerutransmitters that act like pain killers

Adrenal glands purpose and sage

Stress responce
on top of kidney
cortex and medula (medulla is the middle)

Short term:

• nerves stimulate th emedulla directly, that then releases adrenaline. adranaline triggers glycogen to be converted into glucose for more nebergy, this elevated the matabolic rate

Loger term:

• ACTH fro anterior petuitary stimulates the cortex that releases cortisol and aldosterone. help keep sodium and wter which increase the blood pressure.

• The stress itself might be ebacue of lack of food, so ur body starts using protien and fat in ur body for glucose

• Things not paramoutn ot survival are surpressed, liek ur immune system

Whta is elevated metabolic rate

higher blood resure, heart rater, breating rate ect.

Cortisol regulation

hypothalamuz releases CRH

CRH triggers anterior petutitary to release acth

acth TRIGGERS ADRENALS CORTEXT TO RELEASE CORTISOL

the thyroid glang

Metabolism controll

Stimulated by TSH which releases thyroxin (receptors fo rthis hormone foudn on a lot of cells)

Leads to increase metabolic rate:
- energy production
- oxygen consumption (heart, kindey, skeletal muscle)

Negative fedbakc response

Expalint he negative feedbakc system of thyroid

controlled by hypothamamus and petuitary galnd

TRH (tsh releasing hormone) is released by hypothalamus

pituitary grand releases TSH

TSH tells thyroid gland to relaease thyroxin

thuroxin tells the bdy to increae metabolism

one levels are too high it tells the hypothamauls and petuitary to stop releasign hromones

disorders fo the thyoid gland

Low elevels (hypothyroidism):

• not gonan have th eright metabolism,

• weak tored, cold,

• poor memeory,

• goitre (large thyroid lack of iodine - neede for thyroxine- constant stimulation of thhyroid by TSH - increased number/size of cell due to stimulation)

High elvels: Hyper thyrodism

• too much metabolic rates

• fst heart rate

• weight loss

• restlessness

• increase ehat -sweating ect

Pancreas

Regualt blood glucoe sleves: produces insulina nd glacagon (antagonistic)

high glucose - insuline by beta cells

low glusoce - glucagon by aplha cells

What does beta cells do

secrete insulin

send glucose to the liver to be stored as glycogen

makes the cells take in glucose out of blood

what do alpha cells do

secrete glucagon,

breakes down glycogen int he liver into glucode in blood stream

Pancrease diabetes

type 1: cells do not produce insluin (injections)

type 2: reduces insulin production or not binding properly to stimulate regulation (diet and excersise)

Pineal gland

secretes melatonin
or elight, less melatonin

regulates slee

inhibits gonadotropins in children

might be an dantioxidant or neuroprotective agent int eh brain

Prathyroid gland

regulates clasium levels in blood

release prathroid hormone in reposnse to LOW calsium

targets:

• bones (stimulate osteoclasts to break down bones

• Kidney (stimulates reabsorption of calcium from nephron into blood

• intestines: increased absoption of calsium due to elevated vitamin D levels-cells-

Where is the primary source sof sex hormones?

GOnads (testes and ovaries)

What are the 3 type sof sex hormnes

androgen

estrogen

progestin

Expalin which sex produces which sex hormones and what its purpose is

Both produce all 3

Andrgen is predomiannt in males

the other two are predominant in femals

controll developemt for secondayr sex charateristics and sex drive

Expalint eh amle hormnes

hypothalamus releases GnRH - > Pituitary FSH and LH

FSH - sperm production

LH - testorterone

Testosterone

responsible for secondary chaaracteristis (voice, growth, hair, muslce

Sperm rpoduction

Negtaive feedbakc system:

• ris eof testosterone

• increase of inhibin leveles, acts ont he hypo thalamus and ptituitray to inhibi release of GnRH , FSH and LH

Why does testosterone need ot eb regulated?

can make you agressive

expalin female hormones

Hypohtalamuc secreatses GnRH release FSH AND LH

FSH stimualtes egg development in follicles cells (they produce inhibin)

LH also helps with ova production, triggers ovulation and stimulation of estorgen and pregesterone:

• Estrogen edometrial growth, ovulation and calcium absorption, also secondary characteristics (breast, body ahri, pelvis widenin, sex drive)

• Progesterone: edometiral growth but also ihibition

Edomertiral growth is needed to

prep for egg protection

Expalin menopause

Ovaries become less sensitive to FSH and LH therefore done mature the folicles and dont undergo ovulation

expalin stages of female cylce

Follicular phase:

Menstration, maturation, new follicle : LH, FSH and estorgen kept low

Ovulation:

Folicle inscrease estrogen, increases LH and FSH, egg is released; endometiral lining thickes as food for baby

Luteal phase = dead folicle releases low estrogen and LH AND FSH, endometrium thickets to support new baby

What are the 3 subcategories for sensory neurons

Nociceptors - pain

Mechanoreceptior - touch

Proprioceptors (body perception - position)

Write a short explanation of how the message got from your fingertip to your brain.

Transmission of Message from Fingertip to Brain:

When you touch something, sensory receptors in your skin detect the sensation and send electrical signals through nerves to the spinal cord. From there, the signals travel up the spinal cord to the brain, where they are processed and interpreted, allowing you to perceive the touch.

• Explain the 4 extra parts of the Brain

• Ventricle: Fluid-filled cavities in the brain that help cushion and protect the brain.

• Thalamus: Acts as a relay station for sensory information to the cerebral cortex.

• Olfactory bulb: Processes information about smell.

• Optic Chiasm: Point where optic nerves cross over, allowing visual information from each eye to be processed together.

What is Grey and white matter int he brain and why is it important?

Grey matter consists of neuronal cell bodies and white matter consists of myelinated axons. Grey matter processes information while white matter facilitates communication between different brain regions. Both are crucial for cognitive functions and overall brain activity.

Explain the urine feedback controll system

hyPo- pit → ADH → affects urine
+ADH = - Urine
-ADH = +Urine

What is a dieuretic?

Hormone that makes you pee:
coffee

How does ADH make you stop peeing?

When water level drop low, the hypothalamus signals to secrete more ADH - ADH makes tke collecting duct more permeable to water, making water go back into the blood (decreaseing urine production)

Taxis

Taxis involves the turning of an animal's body relative to a stimulus - either toward or away.

Kinesis

Kinesis is a random movement of an animal in relation to a stimulus, like cockroaches scattering when the light is turned on.

Adrenal gland response system

hypo → CRH → pit → acth → cortex → Cortisol and aldosterone (cortisol limis acth and crh)

Sympahtetic nerves → medula → adrenaline

Thyroid feedbakc systehm

hypo → TRH → Pit → TSH → Thyroid gland → thryoxine (goes ot pit an d hypo to stop production) - > peripheral tissues

If metabolism is loo low is triggers the hypothalamus to release trh ,once high enough…

Pancrease feedback system

+glucose → pancrease (beta cells)→ +insulin

- Glucose → pancrease (alpha cells) → +glucogen

Pineal Gland

+ light → pineal gland → - melatoning

Parathyroid glands

- clacium → parathyroid gland → prathyroid hormone →

→Bones

→ kidney

→ intestine

Male gonad hormones system

hypo → gnrh → pit → FSH LSH→ SPerm (FSH) , Testosterone (LH)
+testosterone → sperm, secondary sex characteristics, inhibin → stop GNRH, FSH and LH

ANdrogen?

tESTOSTERON