HOMEOSTASISREVIEW

• Endocrine glands and other systems maintain physiological equilibrium mediated by hormones.

• A study of the interaction between the neural and endocrine systems leads to an examination of the functioning of the central and peripheral nervous systems and their ability to sense the environment and respond to it.

The two major concepts developed in this unit are:

1. The human organism regulates physiological processes, using electrochemical control systems

Nervous system

2. The human organism maintains homeostasis through the use of complex chemical control systems Endocrine

system

1.The human organism regulates physiological processes, using electrochemical control systems.

•Students should be able to demonstrate an understanding that:

•the human organism, like other organisms, maintains control over its internal environment with neural systems by

Neuron

2) Cell body

1) Dendrite- receives sensory info

3) Nucleus

4) Neurilemma (thin layer on outside of myelin sheath, responsible for regeneration)

5) Myelin sheath6) Schwann cells-

make up the myelin sheath

7) Axon 8) Axon ending

9) Nerve ending (same as axon ending)

10) Nodes of Ranvier- gaps between myelin sheath

11) Saltatory conduction- impulse jumps from node to node

Neuron• describing the structure and function

of a neuron and myelin sheath,

Nerve Impulse

What type of neuron is this?

Sensory Neuron!

Pola

rized

Depol

arize

d

Repol

arize

d

Restin

g

pote

ntia

l

Restin

g

pote

ntia

l

Terms:1) Polarized2) Depolarized3) Repolarized4) Resting potential

Wave of Depolarization• explaining the formation and

transmission of an action potential

Label:a) the section of

axon that has resting potential

b) polarizedc) depolarizedd) repolarized

a

bcd

d c

c

, b

Direction of impulse in axons

Action PotentialTerms:1) Polarized2) Depolarized3) Repolarized4) Sodium/

Potassium Pump5) Hyperpolarization

6) Refractory Period

7) Active transport8) All-or-none

response9)Threshold10)Action potential

http://www.brookscole.com/chemistry_d/templates/student_resources/

shared_resources/animations/ion_pump/ionpump.html

Sodium/Potassium pump animation:

1

2

3

4

Synapse• explaining the formation and transmission of a signal

across a synapse or neuromuscular junction and the main chemicals and transmitters involved; i.e., norepinephrine, acetylcholine and the enzyme that breaks them down

Terms:1) Presynaptic terminal2) synaptic vesicles3) Synapse4) neurotransmitters5) Active

transport(exocytosis)6) acetylcholine7) Cholinesterase or enzyme8) Diffusion

Synapse

1) Presynaptic terminal

6) Active transport (exocytosis)

8) Postsynaptic Neuron

7) acetylcholine

8) Cholinesterase or enzyme

10)Diffusion of neuortransmitter across synapse

2) Synaptic vesicle

3) Synapse

Nerve Impulse1) Excitatory neuron

Causes depolarization (Na+ in)2) Inhibitory neuron

Causes hyperpolarization (K+ out)

3. Summation 2 or more neurons release their neurotransmitters at the same time to cause an action potential in the post-synaptic neuron.

Types of Synapses

Excitatory• Causes

depolarization of the post synaptic neuron = action potential

• Na+ channels on post synaptic neuron open

(= Na+ in)

Inhibitory• Causes

hyperpolarization of the post synaptic neuron (axon becomes more negative)

• This inhibits depolarization

• K+ channels on the post synaptic neuron open

• (= K+ out)

Depends on the type of receptor activated NOT the type of neurotransmitter.

SummationTwo or more neurons

release neurotransmitters at the same time to cause an action potential– Neurons A and B must

work together to cause an action potential in neuron D

– Alone, they cannot reach threshold

Is neuron C excitatory or inhibitory?

1) stimulus

2) affectorsensory receptor converts stimulus into nerve impulse

Effector (muscle)

Sensory neuron (in)

Interneuron (CNS)

11) White matter

12) Grey matter

Motor Neuron (out)

ASIME

Has myelin

No myelin

Diploma Question

Structure:

Function: Transmits impulses to the central nervous system

Receives sensory stimulation

Carries out intructions from the CNS; is a muscle

Transmits impulses from the CNS to the effector

Numerical Response #33. Identify the structure, as numbered above, that

performs each of the functions given below.

Structure:

Function: Transmits impulses to the central nervous system

Receives sensory stimulation

Carries out instructions from the CNS; is a muscle

Transmits impulses from the CNS to the effector

2 1 5 4

1.The human organism regulates physiological processes, using electrochemical control systems.

• identifying the principal structures of the central and peripheral nervous systems and explaining their functions in regulating the voluntary (somatic) and involuntary (autonomic) systems of the human organism; e.g., cerebral hemispheres, cerebellum, pons, medulla, hypothalamus, pituitary, spinal cord, sympathetic and parasympathetic nervous systems

PARTS OF THE BRAIN AND THEIR FUNCTIONS

Cerebrum- frontal, parietal, temporal and occipital lobes

hypothalamus

Pituitary – master gland

Pons – relay centre

Medulla oblongata- autonomic NS

Frontal lobe- motor, thinking

Parietal lobe- sensory

Occipital lobe- vision

Temporal lobe- hearing, smelling (olfactory)

Cerebellum- balance

Spinal cord

Temp, metabolism, hunger, thirst, sleep and sex drive

Around other side

SOMATIC (voluntary) and AUTONOMIC (involuntary) SYSTEMS

SOMATIC NERVESControl the

i) neurons relay information about the environment to the CNS

ii) neurons impulses away from the CNS

AUTONOMIC NERVESSpecial motor nerves that are designed to control the

i) – fight or flightii) – rest and digest

skeletal muscles, bones and skinSensory

Motor

internal organs of the body.Sympathetic

Parasympathetic

PARASYMPATHETIC AND SYMPATHETIC N.S.

PARASYMPATHETIC AND SYMPATHETIC N.S.

Which neurotransmitters do the parasympathetic and sympathetic nervous systems use?

Parasympathetic uses acetylcholine.

Sympathetic uses norepinephrine.

NERVOUS SYSTEM

Central N.S. Peripheral N.S.

Brain Spinal Cord

Somatic

Autonomic

Parasympathetic

Sympathetic

Motor Sensory

1.The human organism regulates physiological processes, using electrochemical control

systems.• explaining how human organisms

sense their environment and their spatial orientation in it; e.g., auditory, visual, skin receptors, olfactory, proprioceptors.

• These are found in tendons, muscles, ligaments and joints and provide information to the brain regarding the adjustment of posture and movement. They influence the responses required for the body to correct imbalance due to tension in muscles or ligaments caused by a twisted foot, or unforeseen stretching movement. The spinal cord and brain centers are made aware of the situation and respond accordingly.

Info to brain about body

Outer Middle Inner

Pinna

Tympanic membrane

Ossicles

Eustachian tube

Auditory Canal

Semicircular canals - balance

Cochlea and organ of corti - where hearing happens

Auditory Nerve

PARTS OF THE EYE1) Aqueous humour (Anterior

chamber)2) Vitreous humour 3) Photoreceptors (rods and cones) 4) Cornea 5) Lens6) Pupil7) Iris8) Ciliary body9) Sclera10)Choroid11)Retina12)Fovea centralis13)Optic nerve14)Blood vessels15)Blind spot16)Eye muscle17)Rectus muscle*18)Suspensory ligaments*19)Conjunctiva* (optional)

ALSO KNOW!1) Pathway of light into eye2) Accommodation3) Optic chiasma

ScleraChoroidRetina

Fovea centralis

Optic nerveBlood vessels

Blind spot

Blood vesselsVitreous humor

Ciliary muscleControls shape of lens

Iris (colored muscle)

Conjunctiva

Pupil (hole)Lens (focuses)

Aqueous humor

Cornea

Suspensory ligament

Eye muscle Rectus muscle

The Eye

Hard outer white part

Rods(dim) & Cones(color)

Called accommodation

Clear, refracts light onto centre of lens

Controls size of pupil

Where optic nerve leaves eye.

No rods or cones

Black layer, absorbs stray light & contains blood vessels

Mostly cones

To occipital lobe

1)Pathway of light into eye-

Cornea, pupil, lens, retina2) Accommodation- the lens changes shape to focus3) Optic chiasma- point in brain where the optic nerves cross over

A person with a vitamin A deficiency may have night blindness. The glare from the headlights of an approaching car will temporarily reduce that person’s visual capacity. The primary structures associated with this change are thea) cornea and lensb) retina and rod cellsc) fovea and blind spotd) choroid and cone cells

Diploma Question

• the principal endocrine glands of the human organism; e.g., the hypothalamus/pituitary complex, thyroid and adrenal glands, pancreas islet cells

2. The human organism maintains homeostasis through the use of complex chemical control

systems.

• describing the hormones of the principal endocrine glands; i.e., TSH/thyroxine, ACTH/cortisol glucagon/ insulin, HGH, ADH, epinephrine, norepinephrine, aldosterone

2. The human organism maintains homeostasis through the use of complex chemical control

systems.

12

345

6789

10

1. Hypothalamus2. Pituitary Gland3. Thyroid gland4. Parathyroid*5. Liver (stores glucose)6. Pancreas

7. Adrenal Gland*8. Kidney (water

regulation)9. Ovary

10. Testes

* Are not endocrine glands, but are target tissue for hormones.

Gland/Organ Hormones

1 Thyroid Thyroxin, calcitonin

1a Parathyroid

Parathormone (PTH)

2 Liver Insulin (glucose glycogen) and glucagon (glycogen glucose)

3 Pancreas Insulin, glucagon

4 Adrenal glands

Cortex-Aldosterone, Cortisol

Medulla- Epinephrine (Adrenaline)

5 Kidney Aldosterone, ADH

6 Ovary Estrogen, Progesterone

7 Testes Testosterone

8 Hypothalamus

GnRH, TSH-RF, ACTH-RF, ADH, oxytocin

9 Pituitary TSH, ACTH, FSH, LH, MSH, (tropic) and prolactin, GH. Post: ADH, Oxytocin

Gland Hormone Target EffectThyroid Thyroxine All body cells Increase metabolic rate

Calcitonin“calcium – bone – in”

Bones, kidneys and small intestine

Stores Ca2+ in bones, decreases calcium in blood

Parathyroid Parathormone (PTH)

Bones, kidneys and small intestine

Releases calcium from bones, increasing blood calcium

Pancreas Insulin (from beta cells)

All cells, liver Lowers blood sugar, stores glucose as glycogen

Glucagon (from alpha cells)

All cells, liver Raise blood sugar, converts glycogen glucose

Adrenal GlandMedulla

Adrenaline All cells Sympathetic Nervous system response (prepare for an emergency)

Noradrenaline All cells

Adrenal GlandCortex

Aldosterone Kidney Sodium is reabsorbed into blood and water follows by osmosis

Cortisol All body cells Anti-inflammatoryReleases glucose and a.a. to repair injury

Testes TestosteroneIn interstitial cells

Seminiferous tubules, other cells

Increases sperm prod. , bone growth, larynx, hair…

Ovaries Estrogen Secondary sex cells and endometrium

Secondary sex charGrowth of the endometrium

Progesterone Uterus Maintains the endometrium by preventing contractions

PituitaryPosterior

ADH Kidney Reabsorbtion of water into blood

Oxytocin Uterus and breasts Contractions

PituitaryAnterior

Tropic Hormones- they stimulate other glands to produce hormones

GH Most cells Promotes growth

TSH Thyroid Releases thyroxin, which increases metabolism

ACTH Adrenal cortex Aldosterone and cortisol

Prolactin (PRL) Mammary glands Milk production

FSH Ovaries and testes Production of ova, estrogen and sperm

LH Ovaries and testes Female - Causes corpus luteum to produce est. and prog. Male - interstitial cells produce testosterone

•explaining the metabolic roles hormones play in homeostasis; i.e., thyroxine to metabolism, insulin to blood sugar regulation, HGH to growth, ADH to water regulation

2. The human organism maintains homeostasis through the use of complex chemical control

systems.

Diploma Question

In humans, when iodine levels are adequate, abnormally high TSH secretion would likely result ina) nervousness and weight gainb) nervousness and weight lossc) sleepiness and weight gaind) sleepiness and weight loss

Diploma Question

A hormone that regulates glucose levels in the blood and a hormone that regulates Na+ in the blood and, indirectly, water reabsorption by the kidneys are, respectively,

a) aldosterone and insulinb) glucagon and aldosteronec) epinephrine and glucagond) insulin and antidiuretic hormone

28. Humans, as well as rats, release glucagon in response to stress. The row below that identifies the gland that secretes glucagon and the target organ of glucagon in humans is

Row Secreting GlandTarget

Gland/Organ

A. 2 3

B. 4 2

C. 3 2

D. 3 4

8

9

1a

Diploma Question

Diploma Question

The endocrine function of the pancreas was studied in Canada using dogs as experimental animals. The pancreatic cells with an endocrine function area) islet cellsb) blood cellsc) Sertoli cellsd) interstitial cells

Steroid hormones • SLOW• Enter cell

Protein hormones

• Prompt (fast)• Attaches to receptors

on cell membrane• Ex. Insulin, growth

hormone and epinephrine (adrenaline)

• Most hormones are this type

Negative feedback loop

Hypothalamus

TSH-RF

Pituitary

Thyroid Gland

TSH

Thyroxine

Negative Feedback

Low Metabolism

Need iodine to make thyroxine

Diploma Question

Normally, inhibition of the pituitary gland would occur if the secretion of hormone Xa) increased, causing a decrease in the secretion of hormone Yb) decreased, causing a decrease in the secretion of hormone Yc) increased, causing an increase in the secretion of hormone Yd) decreased, causing an increase in the secretion of hormone Y

Control of the Secretion of Hormone Y by the Pituitary Gland

•explaining how the endocrine system allows human organisms to sense their internal environment and respond appropriately; e.g., sugar metabolism

2. The human organism maintains homeostasis through the use of complex chemical control

systems.

Feedback loop

Insulin

Glucagon

•comparing the endocrine and neural control systems and explaining how they act together;

2. The human organism maintains homeostasis through the use of complex chemical control

systems.

e.g., stress and the adrenal gland

Adrenal Gland

Medulla

Adrenaline All cells Sympathetic Nervous system response (prepare for an

emergency)

Noradrenaline

All cells

Gland Hormone Target Response

The adrenal gland releases epinephrine in the blood stream. This stimulates the medulla to increase heart rate and breathing rate through nerve pathways.

In general, circulating epinephrine and norepinephrine released from the adrenal medulla have the same effects on target organs as direct stimulation by sympathetic nerves, although their effect is longer lasting.

A listing of some major effects mediated by epinephrine and norepinephrine are:

•Increased rate and force of contraction of the heart muscle: this is predominantly an effect of epinephrine acting through beta receptors. •Constriction of blood vessels: norepinephrine, in particular, causes widespread vasoconstriction, resulting in increased resistance and hence arterial blood pressure. •Dilation of bronchioles: assists in pulmonary ventilation. •Stimulation of lipolysis in fat cells: this provides fatty acids for energy production in many tissues and aids in conservation of dwindling reserves of blood glucose. •Increased metabolic rate: oxygen consumption and heat production increase throughout the body in response to epinephrine. Medullary hormones also promote breakdown of glycogen in skeletal muscle to provide glucose for energy production. •Dilation of the pupils.•Inhibition of certain "non-essential" processes: an example is inhibition of gastrointestinal secretion and motor activity.

Common stimuli for secretion of adrenal medulla hormones include exercise, hypoglycemia, hemorrhage and emotional distress.

• describing, using an example, the physiological consequences of hormone imbalances.

2. The human organism maintains homeostasis through the use of complex chemical control

systems.

What would happen as a result of too much

a) GH? _______________________________________b) Thyroxine? _____________________________________c) Cortisol? _______________________________________

Gigantism or acromegaly (in adults)

Hyperthyroidism- weight loss, nervousness, insomniaCushing’s Syndrome: Weight gain, weakened immune

system