Biology 12 unit 3

Explain the negative feedback system for drop in blood pressure

1. A drop in blood pressure is detected

2. The medulla oblongata in the brain receives this signal

3. The medulla oblongata stimulates the nerve pathway

4. The nerve pathway signals the heart to increase its rate

5. The nerve pathway also signals arterioles to constrict

6. Increased heart rate and arteriolar constriction rise blood pressure

7. The rise in blood pressure is detected inhibiting further stimulation of the heart and arterioles

8. Blood pressure returns to normal

Explain a positive feedback look for the suckling by the baby during lactation

1. The suckling of the baby is sensed by the nerve endings

2. The hypothalamus see this

3. It releases oxytocin and the milk duct contractions

4. Milk is ejected

5. Increased suckling

6. Only stops when suckling stops ( baby is full)

What is thermoregulation

Maintenance of the body temperature within a range that enables cells to function efficiently

What are ectotherms

An animal that is dependent on external sources of body heat

What is an endotherm

An animal that is dependent on or capable of the internal generation of heat

What is hypothermia

A condition in which the bodies core temperature falls below the normal range

Why is freezing dangerous for cells

It can cause crystals to form, which may puncture cell membranes and lead to cell damage or death.

What is the source, target and action of ADH

Source- pituitary gland

Target-kidneys

Action- water reabsorption

What is the source, target and action of aldosterone

Source- adrenal gland

Target- kidneys

Action- enhances renal function

What is the source, target and action of insulin

Source- beta cells islets of langerhans

Targets- liver

Action- decreases blood sugar levels

What is the source, target and action of glucagon

Source- alpha cells islets of langerhans

Targets- liver

Action- raising blood sugar

What is the source, target and action of epinephrine and adrenaline

Source- adrenal medulla

Target- muscle, lungs, heart, and blood vessels

Action- fight or flight

What is the source, target and action of cortisol

Source- adrenal gland (adrenal cortex)

Target- every cell and organ in the body

Action- converts amino acids to glucose and breaks down fats

What is the source, target and action of ACTH

Source- anterior pituitary gland

Targets- adrenal cortex

Action- stimulates cortisol which regulates metabolism

What is the source, target and action of thyroid hormone

Source- thyroid gland

Target- brain, liver, skin

Action- regulates metabolism and growth

What is the source target and action of TSH

Source- anterior pituitary gland

Targets- thyroid gland

Action- tells your thyroid how much thyroid hormone to make

What is the source, target and action of TRH

Source- cell bodies of the hypothalamus

Target- Anterior pituitary gland

Action- stimulate cells in the anterior pituitary gland to release TSH

What is the source target and action of calcitonin?

source-Thyroid gland

Target- Bones

Action-lowers blood calcium levels

What is the source target and action of PTH?

Source-Parathyroid gland

Target-Bones

Action-Increases blood calcium levels

What is the source target an action of growth hormone?

Source-Anterior pituitary gland

Target-Liver and muscles and bones

Action-Stimulates bones and tissue growth

What is the source target in action of prostaglandins?

Source-All tissues and organs

Targets-You tissues

Action-Mediates inflammation and pain

What is the source target in action of Anabolic steroids

Source-Synthetic versions

Targets-Muscle cells

Action-Promotes muscle growth and maculation

What is the source target in action of EPO?

Source-Kidneys

Targets-Bone marrow

Action-Boost red blood cell production

What is the source target in action of testosterone?

Source- interstitial Cells

Target-Reproductive tissues

Action-development of male reproductive organs

What is the source target in action of FSH?

Source-Anterior pituitary gland

Targets-follicle

Action-Maturation of sex cells in female

What is the source target in action of LH?

Source-Anterior pituitary gland

Target-Corpus Luteum

Action-Triggers, ovulation, and progesterone

What is the source target in action of estrogen?

source-Ovaries

Target-Reproductive organs

Action-Female reproductive development and regulates menstrual cycle

What is the source target in action of progesterone?

Source-Corpus luteum

Target-Uterus

Action-Prepares uterus for pregnancy

What is the source target in action of prolactin?

source-Anterior pituitary gland

Targets-Mammary glands

Action-Milk reproduction

What is the source target in action of oxytocin?

Source-Posterior pituitary gland

Target-Uterus and mammary gland

Action-Stimulates uterine contractions during childbirth and milk production

What is a source target action of MSH?

Source-Anterior pituitary gland

Targets-Skin

Action-Stimulates melanin production

What is homeostasis?

The ability of a cell or organism to maintain a stable internal environment when outside conditions change

What is negative feedback

A change in some variable triggers mechanics that reverse the change

What is positive feedback?

A change in some variable triggers mechanisms that amplify the change

What are the two major systems of homeostasis?

The endocrine system and the nervous system

What is the endocrine system?

The endocrine system is slow communication messages travel by means of chemical hormones from a source to a target. It involves their source target in action.

What is the nervous system?

The nervous system is fast communication with high-speed nerve impulses that are conveyed along. Nerve cells called neurons.

What is a gland? What are the type types of glands?

It is a secretary organ

Exocrine glands and endocrine glands

What are exocrine glands?

They have ducks through which secretion travels an example is sweat, mucus, tears, digestive enzymes

What is an endocrine gland?

It is ductless glands, and it produces hormones and secretes them into the bloodstream

What are the three things that define an animal hormone?

1. It is a specific molecule synthesized and secreted by an endocrine gland

2. It is released into the circulatory system

3. It travels via the blood to another area of the body, where it elect specific biological responses from target cells which have receptors for the hormone

What are receptors?

• Proteins within the target cell or on its surface

• Specific for certain hormones

• Hormones bind to receptors molecules and it is the hormone/receptor complex that triggers the effect

What are the three general classes based on their chemical structure of hormones?

Steroid hormones, amino acid derivatives and polypeptides

What are steroid hormones?

• Includes the sex hormones

• Fat soluble

• Cholesterol is the precursor

• examples include estrogen, progesterone, and testosterone

What are amino acid derivatives?

• Hormones derived from amino acids, Especially tyrosine

• Water soluble

• Smaller than a steroid molecule

• Example is Epinephrin and adrenaline

What are polypeptides?

• The most diverse

• Chains of amino acid

• Example as insulin

What are the three principles governing hormone activity?

1. Hormones can act at very low concentrations

2. A given hormone can affect different target cells in an animal differently or very in effects from one species to another

3. A hormone trigger specific changes in a target cell by one of two general Mechanisms

   A hormone can Enter the nucleus of the target cell and influence the expression of cells genes

   A hormone can attach to the cell surface and influence activity within the cell through cytoplasmic intended call second messenger

How do steroid hormones enter the cell?

1. Steroid hormone from the bloodstream arrives at the target and passes easily through the cell membrane because it is lipid soluble

2. The steroid hormone is then able to enter the nucleus through the nuclear membrane

3. Once in the nucleus, the hormone will then combined with a receptor molecule from hormone receptor complex

4. The hormone receptor complex well, then, combined with an acceptor molecule, located in the chromatin and form a receptor acceptor complex

5. The acceptor is associated with the DNA/gene which will activate or turn on the gene

6. The gene is then copied from DNA into a working copy called mRNA

7. The working copy of mRNA goes from the nucleus into the cytoplasm where it is translated or converted into a sequence of amino acids producing the first second third levels of protein structure

What are the anterior lobes two steps to hormones?

1. Releasing factors are secreted

2. Target sells synthesize appropriate hormone in response to releasing factor

What happens during short term stress response?

• Increase heart rate

• Increase blood pressure

• Liver converts glycogen to glucose and releases glucose to the blood

• Dilation of bronchioles

• Decreased digestive system activity

• Decreased urine output

• Changes in blood flow patterns

• Increase alertness

What is the long-term effects of stress caused by aldosterone?

• Retention of sodium and water by kidneys

• Increase blood volume in blood pressure

What are the long-term affects of cortisol on stress response?

• Increase blood sugar

• Proteins and fats broken down for energy

What are the functions of the testes?

• Produce sperm cells

• Produce the hormone testosterone

What is the function of seminiferous tubes?

• Produce immature, sperm cells

What is the function of seminal vesicles?

• Secretes fructose into the semen, which provide provides energy for the sperm

What is the function of the prostate gland?

• Secretes and alkaline buffer into the cement to protect the sperm from the acidic environment of the vagina

What is the function of cowpers gland?

• Secrete mucus, rich fluids into the semen that may protect the sperm from acids in the urethra

What is the function of the urethra?

• Carries semen during ejaculation

• Carries urine from the bladder to the exterior of the body

What is the function of the penis?

• Deposit sperm into the vagina during ejaculation

• Contains the urethra

What is the function of ovaries?

• Produce the hormones, Oestrogen and progesterone

• Sites of over development and ovulation

What is the function of the fallopian tubes?

• Carries the ovum from the ovary to the uterus

• Usually the site of fertilization

what is the function of the fimbria

• Sweeps the ovum into the oviduct following ovulation

What is the function of the uterus?

• Pear shaped organ in which the embryo and foetus develop

• Involved in menstruation

What is the function of the cervix?

Separates the vagina from the uterus

Holds the foetus in place during pregnancy

Dilate during birth to allow the foetus to leave the uterus

What is the function of the vagina?

• Extends from the cervix to the external environment

• Provides a passageway for sperm and menstrual flow

• Functions as the birth canal

What happens when there’s no embryo

The corpus luteum stops making progesterone and estrogen, and the endometrium stops developing and breaks down

What are the four Stages in the menstrual cycle

1. Flow

2. Follicular

3. Ovulation

4. Luteal

What happens during the flow phase? And how long does it last?

Menstruation the endometrium is shed through the vagina and last one to five days

What happens during the follicular phase?

Follicles containing eggs develop in ovaries and the endometrium begins to develop FSH from the anterior pituitary gland helps follicles develop this increases oestrogen this process last 6 to 13 days

What happens during ovulation?

One egg cell burst from the follicle in ovary and enters oviduct Towards the uterus, LH is produced from the pituitary gland. This happens on day 14.

What happens during the luteal phase

Follicle turns into yellow body from LH oestrogen is produced and so is progesterone if pregnancy doesn’t occur the endometrium is maintained this happens on day 15 to 28

What are the steps in menstruation?

1. Anterior pituitary releases FSH

2. FSH stimulates follicles to grow

3. As follicle grows cell of follicle releases, estrogen, larger amounts of secreted oestrogen increases

4. Oestrogen stimulates the endometrium to begin to develop

5. High levels of oestrogen feedback to pituitary to turn off FSH

6. Anterior pituitary, then secretes LH

7. LH promotes ovulation of the fully developed follicle

8. Corpus selenium continues to secrete oestrogen as well as progesterone

9. Progesterone maintains endometrium

10. SH when no fertilization takes place egg dies, and LH secretion stops

11. Without any LH corpus lithium cannot be maintained the progesterone secretion will stop

12. With progesterone stops menstruation begins

What takes place during the transport of epithelium

1. Filtration between the glamorous and Bowmans capsule

2. Reabsorption good materials are made from the Filtrate/nephron back into the bloodstream

3. Secretion the bad waste or access materials are removed from the blood into the filtrate

What are the two parts of the nervous system?

Central nervous system and peripheral nervous system

What does the Central nervous system involve

The brain and the spinal cord

What does the peripheral nervous system involve?

Somatic nerves, and autonomic nerves

What are The somatic nerves

Voluntary sensor and motor responses

What is the autonomic nerves?

Involuntary sympathetic, which is your fight or flight response and your parasympathetic, which is your calm, relaxed response

What are neurons?

The functional unit of the nervous system

What are the three groups of neurons?

1. The sensory neurons which are photo receptors in the eyes, fear the afferent neurons

2. Inter neurons, they link neurons within the body. They are called association neurons.

3. Motor neurons, they are linked to muscles also called efferent neurons

What are the events of the reflex arc

1. Stimulus causes action potential in the sensory receptor

2. Message travels along sensory dentries

3. Message travels along sensory axon

4. Message reaches and turn on dendrite

5. Message splits one to brain one to motor neuron dendrite

6. Message travels along motor neuron axon

7. Message causes muscles to contract

What is an action potential?

• Is an all or none event

• Is unidirectional

• Has the same amplitude each time?

What is the process of action potential?

1. The action potential arrives at the terminal button

2. The membrane will start to become leaky to calcium ions

3. Calcium ions, move towards the neurotransmitters in vesicles to help the neurotransmitters fuse with the cell membrane of the terminal button of the pre-synoptic cell

4. The vesicle fuses with the cell membrane, allowing the neurotransmitter to exit into the synaptic gap via exocytosis

5. The neurotransmitter will then diffuse across the synaptic gap

6. The neurotransmitter will bind with a specific cell membrane receptor, and the postsynaptic cell

7. If the neurotransmitter is excitatory it will lead to a graded potential in the postsynaptic cell if the neurotransmitter is inhibitory, it will lead to the hyperpolarization of the post synaptic cell

What is nerve impulse theory?

The wave of depolarization sweeps the length of the axon ending at the terminal button. There is a short refractory period of several milliseconds during which the normal ion distribution is reestablished an impulse cannot be initiated during this. Period.

What is the pituitary gland?

The master gland, it secretes hormones that influence a wide range of functions from body growth to human reproduction

What is a thalamus?

A relay station for all sensory input

What is the hypothalamus?

• Governs the autonomic nervous system, and the pituitary gland

• Body temperature

• Appetite

• Thirst

What is the frontal lobe?

The front of the brain responsible for personality, decision-making planning, and problem-solving

What is the occipital lobe?

The back of the brain responsible for vision

What is the corpus Callosum

Connect left and right hemisphere

Allows left, and right hemisphere to communicate

What is the pons

Relay station to and from the cerebellum

What is the medulla oblongata?

Responsible for breathing, heart rate and blood pressure

What is the cerebellum?

Responsible for balancing coordination

What is the temporal lobe

Hearing auditory cortex memory

What is the Parietal lobe

Pressure temperature

3-D battle spatial Perception

Limb awareness

Silent areas

What is the hippocampus?

Gives rise to emotions and allows us to feel other emotions and stories memories

What is the reticular formation?

The primary regulator and consciousness