Human physiology Final Exam UIOWA

Nephron

functional unit of the kidney

vascular and tubular component

Two components of a nephron

basic renal processes

1. glomerular filtration

2. tubular secretion

3. tubular reabsorption

4. Excretion

Filtrate

fluid that passes from the blood through the glomerulus capsule of the kidney

- made up of water, ions, etc.

proteins, cells

Filtrate virtually same as plasma, but without _____________ or ___________

glomerular filtration rate

amount of filtrate formed in all the renal corpuscles of both kidneys

hydrostatic pressure and osmotic forces

Which two gradients control bulk flow across the glomerular capillary?

osmotic, hydrostatic

In the glomerular capsule, _________________ forces work against _______________________ pressure

SNS

Primary control of GFR

constriction

SNS activity will cause (constriction/dilation) in afferent arterioles

Decrease

Constriction of afferent arterioles, and dilation in efferent arterioles will (increase/decrease) GFR

Increase

Dilation of afferent arterioles, and constriction in efferent arterioles will (increase/decrease) GFR

passive diffusion

Non-polar substances travel across membrane due to concentration gradient

Mediated transport

Substances coupled with Na+ travel across membrane

Secretion

Kidneys selectively add some substances (H+, K+, etc.) back into the filtrate

Aldosterone

stimulates Na+ reabsorption in the distal convulated tubule and collecting duct

SNS

What extrinsically controls GFR for the purposes of regulating blood volume?

increases, decreases

If blood volume/pressure is low, SNS activity (increases/decreases) therefore GFR (increases/decreases)

decreases, increases

If blood volume/pressure is high, SNS activity (increases/decreases) therefore GFR (increases/decreases)

RAAS (renin-angiotensin-aldosterone system)

Main regulator of ECF volume

juxtaglomerular apparatus

Specialized cells next to the glomerulus that help to detect/regulate blood pressure

- Releases renin

Renin

An enzyme secreted by the juxtaglomerular cells when blood pressure decreases

- Converts angiotensinogen to angiotensin I

Adrenal cortex

Aldosterone is released by the _____________ ____________

check

Write out changes in GFR and RAAS in a low blood volume/pressure situation

check

Write out changes in GFR and RAAS in a high blood volume/pressure situation

Na+ and Cl-

The loop of henley creates gradient to reabsorb water by pumping out which molecules?

ADH

_______ controls permeability of water

Aquaporins

ADH causes insertion of ___________________ into collecting duct

Plasma osmolarity (hydration/dehydration)

Stimulus for ADH control

Increase

Dehydration would indicate an (increase/decrease) in osmolarity

check

Describe the response when dehydration occurs (high plasma osmolarity)

check

Describe the response when over-hydration occurs (low plasma osmolarity)

Bicarbonate, H+

Kidneys maintain blood pH by reabsorbing __________________ and secreting _____

Na+, H+

Proximal tubule uses pumps to reabsorb _____ and secrete ____

Reabsorbed

HCO3- is (reabsorbed/secreted) indirectly in acid-base balance

respiratory alkalosis

Arise in blood pH due to hyperventilation (excessive breathing) and a resulting decrease in CO2

respiratory acidosis

A drop in blood pH due to hypoventilation (too little breathing) and a resulting accumulation of Co2.

decrease H+ secretion/HCO3- reabsorption

How do the kidneys compensate for respiratory alkalosis?

Increase H+ secretion/HCO3- reabsorption

How do the kidneys compensate for respiratory acidosis?

Functions of the immune system

protect against microbes (viruses, bacteria, fungi, and parasites)

- isolate/remove non-microbial foreign substances

- Destroy cancer cells

innate immunity

- non-specific immune system

- External and internal components

adaptive immunity

- specific immune system

- centered around the ability of lymphocytes to recognize specific pathogens and mount a response

Leukocytes

immune system cells

neutrophils

most common immune cell

eosinophils

immune cell that kills parasites

- 1-3%

Basophils

- <1% of immune cells

- allergic reactions

Monocytes

immune cells that can differentiate into phagocytes

Lymphocytes

2nd most common immune cell

- T & B cells

internal defenses of innate immunity

- Phagocytosis

- Inflammation

- Complement system

- Fever

- Interferons

Types of phagocytes

- neutrophils

- mononuclear phagocyte system

- Organ-specific phagocytes

Cytokines

- released by phagocytes after contact with microbes

- chemical messengers that initiate other immune responses in the body

inflammation

- Local, non-specific response to tissue injury or infection

Goals:

- Bring phagocytes and other immune cells to that area

- Isolate, destroy, or inactivate the pathogens

- Remove debris

- Prepare for subsequent healing and repair

complement system

plasma proteins in the blood which circulate in inactive form (antibodies)

- Activated when bound to an antigen

- Promotes phagocytosis

- Ruptures bacterial walls

- Promote inflammation

Fever

- Generated in response to inflammation

- Macrophages release endogenous pyrogens

- Increases body temp set point (hypothalamus)

Interferons

- Type of cytokine

- secreted by viral infected cells

- Promote resistance to viral infection

primary lymphoid organs

Site of lymphocyte maturation

secondary lymphoid organs

Sites of lymphocyte encounter and activation

- Continuous circulation

Plasma, memory

On binding with an antigen, B cells differentiate into _______________ cells and _______________ cells

Memory cell

Formed after B cells bind to an antigen, enhances future immune responses

B cell receptor

Antigen receptor on the plasma membranes of B cells

- Bind to a specific antigen

antibodies

Plasma cells release ___________________ after exposure to specific antigens

Antibodies

Proteins that attach to antigens, making them more prone to phagocytosis

Cytotoxic (killer) T cells

Destroy host cells harboring anything foreign

- Virus and cancer cells

- Bind to MHC 1

Helper T cells

Bind to MHC II proteins on antigen presenting cells

- fully activate B cells

- stimulate cytotoxic T cell replication

Suppresor T cells

dampens immune system response

humoral immunity

specific immunity produced by B cells that produce antibodies that circulate in body fluids

cell-mediated immunity

type of immunity produced by T cells that attack infected or abnormal body cells

antigen presentation

the display of the antigen fragment in an exposed groove of the MHC protein

Antigen presenting cells

dendritic cells, macrophages, B cells

MHC proteins

- protein that presents foreign antigen on membrane

- allows recognition of "self" and "nonself" cells by the immune system

- Two Classes

MHC I

molecules found on every body cell that presents antigen; signals cytotoxic T to destroy

MHC II

molecules found on macrophages, B cells, and dendrites; signal helper T cells

Cytotoxic

Helper T cells also stimulate _____________________ T cell division

cytotoxins

Cytotoxic T cells secrete ___________________ into their target cell to destroy them

Active immunity

A form of acquired immunity in which the body produces its own antibodies against disease-causing antigens

Primary response (humoral immunity)

First exposure to antigen

1 to 2 weeks before antibody titer reaches efficacy

- Forms memory cells

Secondary response (humoral immunity)

- Repeat exposure to the same antigen

- More rapid response, with efficacy in 1 to 3 days due to memory cells

passive immunity

the short-term immunity that results from the transfer of antibodies from something else

Autoimmune disease

failure of recognition of "self"

- B cells produce antibodies that bind to self-antigens

- Cytotoxic T cells now target self antigens

immunodeficiency

failure of the immune system

- Susceptible to infection and cancer

Hypersensitivity

an exaggerated response by the immune system to environmental antigens

- allergies

natural killer cells

play an important role in the killing of cancer cells and cells infected by viruses

- NOT specific

Cancer and immunity

- Decreased thymus function causes a decrease in cell-mediated immune function

- Cortisol is known to suppress the immune system

23

Somatic cells contain ____ pairs of chromosomes

Diploid cells

cells that have pairs of chromosomes

haploid cells

A cell containing only one set of chromosomes (n)

SRY gene

sex determining region of the Y chromosome

- Produces TDF (testis-determining factor)

Testes

__________________ produce testosterone and mullerian inhibitory factor

Mullerian inhibiting factor

a hormone secreted in male embryos that prevents the developing of female reproductive organs

seminiferous tubules

site of sperm production

Spermatogenesis

production of sperm

Sertoli cells

store and nourish sperm

Leydig cells

produce testosterone

- located in interstitial tissue

Gonadotropins

FSH and LH

luteinizing hormone (LH)

secreted by the pituitary gland to stimulate secondary sex hormone secretion

- Testosterone in males

- Estrogen and progesterone in females

Follicle-stimulating hormone (FSH)

secreted by the pituitary gland to stimulate sex cell production/maturation

- Sperm in males

- Ova in females

GnRH

causes pituitary to release LH and FSH

High levels of testosterone inhibit the release of GnRH

Decrease in production of FSH and LH

Ultimately, decrease in natural sperm and testosterone production

Consequences of anabolic steroid use?

SNS, PNS

An erection is induced by the decrease in (SNS/PNS) activity, and an increase in (SNS/PNS) activity

Cardiovascular

The most common cause of erectile dysfunction is ____________________ disease