CTAP Final

Alveoli of the lungs

Sacs attached to alveolar ducts, composed of simple squamous epithelium. Primary site of gas exchange

Epiglottis composition

Made of elastic and healing cartilage connected by ligaments

Trachea composition and epithelium

Lined with ciliated pseudostratified columnar epithelium with goblet cells

What is the trachea supported by?

C-shaped rings of hyaline cartilage and annular ligaments

Type II alveolar cells

Pneumocytes

Characteristics of type II (pneumocytes) cells

-cuboidal epithelial

-secrete surfactant

-serve as progenitor cells for type I pneumocytes

Bronchioles composition

Small airways that lack cartilage and mucosal glands

Lined by simple cuboidal epithelium

Role of dendritic cells

Capture antigens and deliver them to lymph nodes to initiate immune responses.

Germinal centers of lymph nodes

Found within the cortex of lymph nodes within lymphoid follicles

They are sites of rapid B cell proliferation, somatic hypermutation, and class switching

What cell are present in germinal centers?

Activated B cells, follicular dendritic cells, helper T-cells

Hassal's corpuscles of lymph nodes

Located in the thymus, specifically in the medulla of the thymic lobes...

Involved in maturation of regulatory T cells

Spleen functions

Red pulp- filter blood, removes old/ defective RBC's

White pulp- lymphocyte activation site

Other function: platelet reservoir, immune surveillance, and iron recycling

Peyer's patches locaton and function

Found in submucosa of the distal ileum

Responsible for immune surveillance; contain germinal centers; produce memory lymphocytes

Lymph drainage from left arm to heart

Drains via the thoracic duct, which empties into the junction of the left subclavin and internal jugular veins.

How does the right arm lymph drain?

Drains directly into lymphatic duct.

MALT

mucosa-associated lymphoid tissue

Mucosa-associated lymphoid tissue

It is a diffuse system of lymphoid tissue found in mucosal linings of various organs.

Function: protects mucosal surfaces by detecting and responding to pathogens.

Contains: lymphocytes, macrophages, plasma cells, and germinal centers.

What are some example of MALT

Tonsils, peyer's patches, appendix and bronchial MALT

Pancreas exocrine secretions

Acinar cells produce digestive enzymes e.g. amylase, lipase, proteases

These enzymes will travel through intercalated, intralobular, and interlobular ducts to the duodenum.

Centroacinar cells

Found at the origin of the duct system; part of the exocrine network.

Functions of the liver

Exocrine function: secretes bile for fat digestion

Endocrine function: synthesizes plasma proteins e.g. albumin, clotting factors

Metabolic function: Stores glycogen, detoxifies blood, regulates lipid and amino acid metabolism

Immunologic function: contains kupffer cells (macrophages)

Kupffer cell

Specialized liver-resident macrophages located in the sinusoids

Function: phagocytose old RBC and pathogens, presents antigens to lymphocytes and contribute to Fe recycling and immune surveillance.

Large intestine epithelium

Lined by simple columnar epithelium.

Contains: goblets cells, enterocytes

No villi present anymore.

Crypts of lieberkuhn

Tubular glands housing stem cells and goblets cells

Function of villi in the small intestine

Villi are fingerlike projections of the mucosa in the small intestine.

Function: increase surface area for nutrient absorption

Structure: each villus contains blood capillaries and a lacteal.

Cells of the stomach and their secretions

Parietal cells- secrete HCl and intrinsic factor

Chief cells- secrete pepsinogen

Mucous neck cells- produce mucus

Enteroendocrine cells- release gastrin

Stem cells- regenerate the epithelium

Brunner's glands location and function

Found in the duodenum submucosa.

They secrete alkaline mucus to neutralize stomach acids entering from the pylorus of the stomach.

Hirschsprung's disease pathology

Congenital disorder due to failure of the neural crest cell migration.

Pathology- absence of Auerbach(myenteric) and Meissner(submucosal) plexuses in the distal colon.

Results: no peristalsis- functional obstruction- megacolon.

3 layers of the small intestine (inner to outer layer)

Mucosa- contains epithelium, lamina propria, and muscularis mucosae.

Submucosa- dense connective tissue with blood vessels, glands, and nerves.

Muscularis externa- inner circular and other longitudinal smooth muscle layers.

Helper T cells

(CD4+ cells) play a central role in adaptive immunity.

Functions: activate B cells, activate cytotoxic T cells and macrophages

Release cytokines and form memory helper T cells.

IgA

Found in mucosal secretions; protects mucosal surfaces.

IgA, IgG, IgE, IgM, IgD

antibodies

IgG

Most abundant; crosses placenta; secondary immune response

IgM

First antibody produced; activates complement.

IgE

Involved in allergic reactions and parasite defense

IgD

Mostly found on immature B ells; function not well understood.

Physical barriers of immune system

Skin, mucous membranes of the GI, respiratory and Urogenital tracts.

HCl, defensins,lysozyme, complement proteins, interferons

Layers of urothelium

Lines the urinary tract and its layers are:

Basal cells, intermediate cells, and umbrella cells.

Capillary fenestrae of glomerular filtration

Fenestrated capillaries in the glomerulus:

Allow plasma through but blocks RBC's and platelets

Work with basement membrane and podocytes to form filtration barrier.

Function of kidney

Maintain electrolyte, fluid, and pH balance

Remove metabolic waste

Reabsorb nutrients

Secrete hormones e.g. renin, erythropoietin

Glomerular capsule layers and composition

Parietal layer- simple squamous epithelium

Visceral layer- podocytes with foot processes

Filtrate collects in bowman's space between these layers.

Glomerular basement membrane

Acts as a physical barrier and charge barrier.

Blocks large proteins and an ionic molecules.

Works with fenestrated endothelium and podocytes.

Cells that secrete renin

Renin is secreted by juxtaglomerular cells in the afferent arteriole.

Proximal convoluted tubule

Simple cuboidal epithelium with brush border.

Reabsorbs most filtered nutrients and water.

Distal convoluted tubule

Simp cuboidal, with fewer microvilli.

Active in electrolyte regulation and pH balance.

Bladder epithelium

Lined by transitional epithelium

Allows stretching

Umbrella cells at surface protect underlying tissues.

Ureter epithelium

Lined by transitional epithelium, has mucosa, muscularis, and adventitia layers

Podocytes

Specialized cell of the visceral layer of bowman's capsule.

They wrap around glomerular capillaries.

Form filtration slits with predicates to restrict protein passage.

Correct order of the route the filtrate has to take

Glomerular capsule

Proximal convoluted tubule

Loop of Henle

Distal convoluted tubule

Collecting duct

Renal papilla-> minor calyx-> major calyx

Renal Pelvis-> ureter-> bladder-> urethra

Anterior pituitary hormones

GH; growth

Prl: milk production

Tsh: stimulates thyroid

ACTH: stimulates adrenal cortex

FSH/LH: reproductive hormone

Posterior pituitary hormones

ADH: water reabsorption in kidneys

Oxytocin: uterine contractions, milk letdown

Where is oxytocin produced?

By neurons in the hypothalamus

Hypothalamo-hypophyseal tract functions

Transports ADH and oxytocin from the hypothalamus to the posterior pituitary via axons.

Adrenal cortex layers

Zona glomerlosa- aldosterone

Zona fasciculata- cortisol

Zone reticularis- androgens

Effect of hyperthyroidism

Weight loss, heat intolerance, tachycardia, nervousness, diarrhea, fine tremor

High levels of ADH

Causes water retention in collecting ducts.

Leads to ECF expansion and dilutional hyponatremia

Conn's syndrome

Aldosterone producing tumor

Na retention leading to hypertension

K excretion leading to muscle weakness

Factors that regulate the release of ACTH

Stimulated by CRH from the hypothalamus

Triggered by stress, low cortisol, hypoglycemia, inflammation

Role of thyroid hormones

Increase BMR (basal metabolic rate), oxygen use, heat production

Enhances CNS development and cardiovascular output

Follicle cells of thyroid

produce thyroglobulin, stored in colloid

Parafollicular cells of thyroid

secrete calcitonin

Interstitial cells of testicles

Leydig cells located between seminiferous tubules.

Produce testosterone in response to LH.

Layers of the uterus

perimetrium, myometrium, endometrium

Corpus luteum

Formed from ruptured follicle after ovulation.

Secretes progesterone and estrogen

Maintained by hCG if pregnancy occurs.

What is released during ovulation?

A secondary oocyte surrounded by the corona radiate

Triggered by LH surge

Spermatic cord

Contains vas deferens, testicular artery, pampiniform plexus, lymphatics and nerves.

Wrapped in fascia and cremasteric muscle.

Transformational zone in female cervix

Junction of columnar and stratified squamous epithelium

Site of cervical dysplasia and cancer

Sampled during Pap smear

Fibrous connective tissue enclosing each testis

tunica albuginea

tunica vaginalis parietal and visceral

Bulbourethral glands

Paired glands at base of the penis

Secrete alkaline mucus to neutralize urethra and lubricate it.

Corpus albicans

Fibrotic remnant of a degenerated corpus luteum if no pregnancy occurs.

Corpus cavernosum

Paired erectile bodies of penis, fill with blood during erection

Corpus spongyosum

Surrounds urethra; remains compressible to prevent urethra collapse during erection.